Physical
Activity
and
Health

A Report of the Surgeon General

U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES
Centers for Disease Control and Prevention
National Center for Chronic Disease Prevention and Health Promotion
The President's Council on Physical Fitness and Sports


Suggested Citation

U.S. Department of Health and Human Services. Physical Activity and Health:
A Report of the Surgeon General. Atlanta, GA: U.S. Department of Health and
Human Services, Centers for Disease Control and Prevention, National
Center for Chronic Disease Prevention and Health Promotion, 1996.

For sale by the Superintendent of Documents,
P.O. Box 371954, Pittsburgh, PA 15250-7954,
      s/No17-023-00196-5


Message from Donna E. Shalala
Secretary of HeaIth and Human Services

The United States has led the world in understanding and promoting the
benefits of physical activity. In the 1950s we launched the first national effort to
encourage young Americans to be physically active, with a strong emphasis on
participation in team sports. In the 1970s we embarked on a national effort to
educate Americans about the cardiovascular benefits of vigorous activity, such as
running and playing basketball. And in the 1980s and 1990s we made break-
through findings about the health benefits of moderate-intensity activities, such as
walking, gardening, and dancing.

Now, with the publication of this first Surgeon General's report on physical
activity and health, which I commissioned in 1994, we are poised to take another
bold step forward. This landmark review of the research on physical activity and
health-the most comprehensive ever-has the potential to catalyze a new physical
activity and fitness movement in the United States. It is a work of real significance,
on par with the Surgeon General's historic first report on smoking and health
published in 1964.

This report is a passport to good health for all Americans. Its key finding is that
people of all ages can improve the quality of their lives through a lifelong practice
of moderate physical activity. You don't have to be training for the Boston Marathon
to derive real health benefits from physical activity. A regular, preferably daily
regimen of at least 30-45 minutes of brisk walking, bicycling, or even working
around the house or yard will reduce your risks of developing coronary heart
disease, hypertension, colon cancer, and diabetes. And if you're already doing that,
you should consider picking up the pace: this report says that people who are
already physically active will benefit even more by increasing the intensity or
duration of their activity.

This watershed report comes not a moment too soon. We have found that 60
percent-well over half-of Americans are not regularly active. Worse yet, 25
percent of Americans are not active at all. For young people-the future of our
country-physical activity declines dramatically during adolescence. These are
dangerous trends. We need to turn them around quickly, for the health of our
citizens and our country.

We will do so only with a massive national commitment-beginning now, on
the eve of the Centennial Olympic Games, with a true fitness Dream Team drawing
on the many forms of leadership that make up our great democratic society.
Families need to weave physical activity into the fabric of their daily lives. Health
professionals, in addition to being role models for healthy behaviors, need to
encourage their patients to get out of their chairs and start fitness programs tailored
to their individual needs. Businesses need to learn from what has worked in the past


and promote worksite fitness, an easy option for workers. Community leaders need
to reexamine whether enough resources have been devoted to the maintenance of
parks, playgrounds, community centers, and physical education. Schools and
universities need to reintroduce daily, quality physical activity as a key component
of a comprehensive education. And the media and entertainment industries need to
use their vast creative abilities to show all Americans that physical activity is
healthful and fun-in other words, that-it is attractive, maybe even glamorous!
We Americans always find the will to change when change is needed. I believe
we can team up to create a new physical activity movement in this country. In doing
so, we will save precious resources, precious futures, and precious lives. The time
for action-and activity-is now.


Foreword

This first Surgeon General's report on physical activity is being released on the
eve of the Centennial Olympic Games- the premiere event showcasing the worlds
greatest athletes. It is fitting that the games are being held in Atlanta, Georgia, home
of the Centers for Disease Control and Prevention (CDC), the lead federal agency
in preparing this report. The games' loo-year celebration also coincides with the
CDC's landmark 50th year and with the 40th anniversary of the President's Council
on Physical Fitness and Sports (PCPFS), the CDC's partner in developing this
report. Because physical activity is a widely achievable means to a healthier life, this
report directly supports the CDC's mission- to promote health and quality of life
by preventing and controlling disease, injury, and disability. Also clear is the link
to the PCPFS; origin-ally established as part of a national campaign to help shape up
America's younger generation, the Council continues today to promote physical
activity, fitness, and sports for Americans of all ages.
The Olympic Games represent the summit of athletic achievement. The
Paralympics, an international competition that will occur later this summer in
Atlanta, represents the peak of athletic accomplishment for athletes with disabili-
ties. Few of us will approach these levels of performance in our own physical
endeavors. The good news in this report is that we do not have to scale Olympian
heights to achieve significant health benefits. We can improve the quality of our lives
through a lifelong practice of moderate amounts of regular physical activity of
moderate or vigorous intensity. An active lifestyle is available to all.
Many Americans may be surprised at the extent and strength of the evidence
linking physical activity to numerous health improvements. Most significantly,
regular physical activity greatly reduces the risk of dying from coronary heart
disease, the leading cause of death in the United States. Physical activity also reduces
the risk of developing diabetes, hypertension, and colon cancer; enhances mental
health; fosters healthy muscles, bones and joints; and helps maintain function and
preserve independence in older adults.

The evidence about what helps people incorporate physical activity into their
lives is less clear-cut. We do know that effective strategies and policies have taken
place in settings as diverse as physical education classes in schools, health promo-
tion programs at worksites, and one-on-one counseling by health care providers.
However, more needs to be learned about what helps individuals change their
physical activity habits and how changes in community environments, policies, and
social norms might support that process.

Support is greatly needed if physical activity is to be increased in a society as
technologically advanced as ours. Most Americans today are spared the burden of
excessive physical labor. Indeed, few occupations today require significant physical


acttvtty, and most people use motorized transportation to get to work and to perform
routine errands and tasks. Even leisure time is increasingly filled with sedentary
behaviors, such as watching television, "surfing" the Internet, and playing video
games.

Increasing physical activity is a formidable public health challenge that we must
hasten to meet. The stakes are high, and the potential rewards are momentous:
preventing premature death, unnecessary illness, and disability; controlling health
care costs\ and maintaining a high quality of life into old age.

David Satcher, M.D., Ph.D.                 Philip R. Lee, M.D.

Director
Centers for Disease Control
and Prevention

Assistant Secretary
for Health

Florence Griffith Joyner
Tom McMillen
Co-Chairs
President's Council on
Physical Fitness and Sports


    Preface
from the Surgeon General
U.S. Public Health Service

I am pleased to present the first report of the Surgeon General on physical
activity and health. For more than a century, the Surgeon General of the Public
Health Service has focused the nation's attention on important public health issues.
Reports from Surgeons General on the adverse health consequences of smoking
triggered nationwide efforts to prevent tobacco use. Reports on nutrition, violence,
and HIV/AIDS-to name but a few-have heightened America's awareness of
important public health issues and have spawned major public health initiatives.
This new report, which is a comprehensive review of the available scientific
evidence about the relationship between physical activity and health status, follows
in this notable tradition.

Scientists and doctors have known for years that substantial benefits can be
gained from regular physical activity. The expanding and strengthening evidence
on the relationship between physical activity and health necessitates the focus this
report brings to this important public health challenge. Although the science of
physical activity is a complex and still-developing field, we have today strong
evidence to indicate that regular physical activity will provide clear and substantial
health gains. In this sense, the report is more than a summary of the science-it is
a national call to action.

We must get serious about improving the health of the nation by affirming our
commitment to healthy physical activity on all levels: personal, family, community,
organizational, and national. Because physical activity is so directly related to
preventing disease and premature death and to maintaining a high quality of life,
we must accord it the same level of attention that we give other important public
health practices that affect the entire nation. Physical activity thus joins the front
ranks of essential health objectives, such as sound nutrition, the use of seat belts,
and the prevention of adverse health effects of tobacco.

The time for this emphasis is both opportune and pressing. As this report
makes clear, current levels of physical activity among Americans remain low, and
we are losing ground in some areas. The good news in the report is that people can
benefit from even moderate levels of physical activity. The public health implica-
tions of this good newsare vast: the tremendous health gains that could be realized
with even partial success at improving physical activity among the American
people compel us to make a commitment and take action. With innovation,
dedication, partnering, and a long-term plan, we should be able to improve the
health and well-being of our people.


This report is not the final word. More work will need to be done so that we can
determine the most effective ways to motivate all Americans to participate in a level
of physical activity that can benefit their health and well-being. The challenge that
lies ahead is formidable but worthwhile. 1 strongly encourage all Americans to join
us in this effort.

Audrey F. Manley, M.D`., M.P.H.
Surgeon General (Acting)


Physical Activity and Health

Acknowledgments

Editors

Steven N. Blair, P.E.D., Senior Scientific Editor,
Director of Research and Director, Epidemiology
and Clinical Applications, The Cooper Institute for
Aerobics Research, Dallas, Texas.

Adele L. Franks, M.D., Scientific Editor, Assistant
Director for Science, National Center for Chronic
Disease Prevention and Health Promotion, Centers
for Disease Control and Prevention, Atlanta, Georgia.

Dana M. Shelton, M.P.H., Managing Editor,
Epidemiologist, Office on Smoking and Health,
National Center for Chronic Disease Prevention and
Health Promotion, Centers for Disease Control and
Prevention, Atlanta, Georgia.

John R. Livengood, M.D., M.Phil., Coordinating
Editor, Deputy Director, Epidemiology and
Surveillance Division, National Immunization
Program, (formerly, Associate Director for Science,
Division of Chronic Disease Control and Community
Intervention, National Center for Chronic Disease
Prevention and Health Promotion), Centers for
Disease Control and Prevention, Atlanta, Georgia.

Frederick L. Hull, Ph.D., Technical Editor, Technical
Information and Editorial Services Branch, National
Center for Chronic Disease Prevention and Health
Promotion, Centers for Disease Control and
Prevention, Atlanta, Georgia.

Byron Breedlove, M.A., Technical Editor, Technical
Information and Editorial Services Branch, National
Center for Chronic Disease Prevention and Health
Promotion, Centers for Disease Control and
Prevention, Atlanta, Georgia.

This report was prepared by the Department of
Health and Human Services under the direction of
the Centers for Disease Control and Prevention,
National Center for Chronic Disease Prevention and
Health Promotion, in collaboration with the
President's Council on Physical Fitness and Sports.

David Satcher, M.D., Ph.D., Director, Centers for
Disease Control and Prevention, Atlanta, Georgia.

J~~I~CS S. Marks, M.D., M.P.H., Director, National
Center for Chronic Disease Prevention and Health
Promotion, Centers for Disease Control and
Prcvcntion, Atlanta, Georgia.

Virginia S. Bales, M.P.H., Deputy Director, National
Ccntcr for Chronic Disease Prevention and Health
Promotion, Centers for Disease Control and
f'rcvcntion, Atlanta, Georgia.

f.isa A. Daily, Assistant Director for Planning,
f:valuation, and Legislation, National Center for
(:hronic Disease Prevention and Health Promotion,
(:cntcrs for Disease Control and Prevention,
)\tlanta, Georgia.

Marjorie A. Speers, Ph.D., Behavioral and Social
\cicnccs Coordinator, Office of the Director,
(lormcrly, Director, Division of Chronic Disease
(:oritrol and Community Intervention, National
(:ctircr for Chronic Disease Prevention and Health
Promotion), Centers for Disease Control and
f'rcvention, Atlanta, Georgia.

f:rcclerick L. Trowbridge, M.D., Director, Division of
Nutrition and Physical Activity, National Center for
Chronic Disease Prevention and Health Promotion,
Ccmcrs for Disease Control and Prevention, Atlanta,
Georgia.

l'lorcnce Griffith Joyner, Co-Chair, President's
C:ouncil on Physical Fitness and Sports, Washington,
D.C.

C. Thomas McMillen, Co-Chair, President's Council
on Physical Fitness and Sports, Washington, D.C.
5lmh-a P. Perlmutter, Executive Director, President's
Council on Physical Fitness and Sports, Washington,
D.C.

Editorial Board

Carl J. Caspersen, Ph.D., Epidemiologist, Division
of Nutrition and Physical Activity, National Center
for Chronic Disease Prevention and Health
Promotion, Centers for Disease Control and
Prevention, Atlanta, Georgia.

Aaron R. Folsom, M.D., M.P.H., Professor, Division
of Epidemiology, School of Public Health, University
of Minnesota, Minneapolis, Minnesota.

vii


A Report of the Surgeon General

William L. Haskell, Ph.D., Professor of Medicine,
Stanford University, Palo Alto, California.

Arthur S. Leon, M.D., M.S., Henry L. Taylor Professor
and Director of the Laboratory of Physiological
Hygiene and Exercise Science, Division of Kinesiology,
University of Minnesota, Minneapolis, Minnesota.

James F. Sallis, Jr., Ph.D., Professor, Department of
Psychology, San Diego State University, San Diego,
California.

Martha L. Slattery, Ph.D., M.P.H., Professor,
Department of Oncological Sciences, University of
Utah Medical School, Salt Lake City, Utah.

Christine G. Spain, `M.A., Director, Research,
Planning, and Special Projects, President's Council
on Physical Fitness and Sports, Washington, D.C.

Jack H. Wilmore, Ph.D., Professor, Department of
Kinesiology and Health Education, University of
Texas at Austin, Austin, Texas.

Planning Board

Terry L. Bazzarre, Ph.D., Science Consultant,
American Heart Association, Dallas, Texas.

Steven N. Blair, P.E.D., Senior Scientific Editor,
Director of Research and Director, Epidemiology and
Clinical Applications, The Cooper Institute for
Aerobics Research, Dallas, Texas.

Willis R. Foster, M.D., Office of Disease Prevention
and Technology Transfer, National Institute of
Diabetes and Digestive and Kidney Diseases, National
Institutes of Health, Bethesda, Maryland.

Patty Freedson, Ph.D., Department of Exercise
Science, University of Massachusetts, Amherst,
Massachusetts. Represented the American Alliance
for Health, Physical Education, Recreation and Dance.

William R. Harlan, M.D., Associate `Director for
Disease Prevention, Office of the Director, National
Institutes of Health, Bethesda, Maryland.

James A. Harrell, M.A., Deputy Commissioner,
Administration on Children, Youth, and Families,
(formerly, Deputy Director, Office of Disease
Prevention and Health Promotion, Office of the
Assistant Secretary for Health, Department of Health
and Human Services), Washington, D.C.

Richard W. Lymn, Ph.D., Muscle Biology Branch,
National Institute of Arthritis and Musculoskeletal
and Skin Diseases, National Institutes of Health,
Bethesda, Maryland.

Russell R. Pate, Ph.D., Chairman, Department of
Exercise Science, University of South Carolina,
Columbia, South Carolina. Represented the American
College of Sports Medicine.

Sandra P. Perlmutter, Executive Director, President's
Council on Physical FitnessandSports, Washington,
D.C.

Bruce G. Simons-Morton, Ed.D., M.P.H., Behavioral
Scientist, Prevention Research Branch, National
Institute of Child Health and Human Development,
National Institutes of Health, Bethesda, Maryland.

Denise G. Simons-Morton, M.D., Ph.D., Leader,
Prevention Scientific Research Group, DECA,
National Heart, Lung, and Blood Institute, National
Institutes of Health, Bethesda, Maryland.

Contributing Authors

Lynda A. Anderson, Ph.D., Public Health Educator,
Division of Adult and Community Health, National
Center for Chronic Disease Prevention and Health
Promotion, Centers for Disease Control and
Prevention, Atlanta, Georgia.

Carol C. Ballew, Ph.D., Epidemiologist, Division of
Nutrition and Physical Activity, National Center for
Chronic Disease Prevention and Health Promotion,
Centers for Disease Control and Prevention, Atlanta,
Georgia.

Jack W. Berryman, Ph.D., Professor, Department of
Medical History and Ethics, School of Medicine,
University of Washington, Seattle, Washington.

Lawrence R. Brawley, Ph.D., Professor, University of
Waterloo, Ontario, Canada.

David R. Brown, Ph.D., Health Scientist, Division of
Nutrition and Physical Activity, National Center for
Chronic Disease Prevention and Health Promotion,
Centers for Disease Control and Prevention, Atlanta,
Georgia.

.
VIII


Physical Activity and Health

Lee S. CupIan, M.D., Ph.D., Medical Epidemiologist,
Epidcruiology and Statistics Branch, Division of
C&lnccr prevention and Control, National Center for
Cllronic Disease Prevention and Health Promotion,
Ccntcrs for Disease Control and Prevention, Atlanta,
Georgia.

R,+h J. Coatcs, Ph.D., Chief, Epidemiology Section,
Division of Cancer Prevention and Control, National
ccntcr for Chronic Disease Prevention and Health
f'romotion, Centers for Disease Control and
frcvcntion, Atlanta, Georgia.

C,lrlos J. Crespo, Dr.P.H., M.S., F.A.C.S.M., Public
flculth Analyst, National Heart, Lung, and Blood
Itlstitutc, National Institutes of Health, Bethesda,
Xlaryland.

I.orctta DiPietro, Ph.D., M.P.H., Assistant Fellow
and Assistant Professor of Epidemiology and
I'ublic Health, The John B. Pierce Laboratory and
Y;IIC University School of Medicine, New Haven,
(;onnccticut.

124 K. Dishman, Ph.D., Professor, Department of
f:scrcisc Science, University of Geoigia, Athens,
Georgia.

Michael M. Engelgau, M.D., Chief, Epidemiology
:~nd Statistics Branch, Division of Diabetes
Translation, National Center for Chronic Disease
I'rcvcntionand Health Promotion, Centers for Disease
(:ontrol and Prevention, Atlanta, Georgia.

\Valtcr H. Ettinger, M.D., Professor, Internal Medicine
and Public Health Sciences, Bowman Gray School of
Medicine, Winston-Salem, North Carolina.

David S. Freedman, Ph.D., Epidemiologist, Division
of Nutrition and Physical Activity, National Center
for Chronic Disease Prevention and Health
Promotion, Centers for Disease Control and
Prevention, Atlanta, Georgia.

Frederick Fridinger, Dr.P.H., C.H.E.S.., Public Health
Educator, Division of Nutrition and Physical
Activity, National Center for Chronic Disease
Prevention and Health Promotion, Centers for
Disease Control and Prevention, Atlanta, Georgia.

Gregory W. Heath, D.Sc., M.P.H., Epidemiologist/
Exercise Physiologist, Division of Adult and
Community Health, National Center for Chronic
Disease Prevention and Health Promotion, Centers
for Disease Control and Prevention, Atlanta, Georgia.

Wendy A. Holmes, M.S., Health Communications
Specialist, Division of Nutrition and Physical
Activity, National Center for Chronic Disease
Prevention and Health Promotion, Centers for
~Disease Control and Prevention, Atlanta, Georgia.

Elizabeth H. Howze, Sc.D., Associate Director for
Health Promotion, Division* of Nutrition and
Physical Activity, National Center for Chronic
Disease Prevention and Health Promotion, Centers
for Disease Control and Prevention, Atlanta,
Georgia.

Laura K. Kann, Ph.D., Chief, Surveillance Research
Section, Division of Adolescent and School Health,
National Center for Chronic Disease Prevention and
Health Promotion, Centers for Disease Control and
Prevention, Atlanta, Georgia.

Abby C. King, Ph.D., Assistant Professor of Health
Research and Policy and Medicine, Stanford
University School of Medicine, Palo Alto, California.

Harold W. Kohl, III, Ph.D., Director of Research,
Baylor College of Medicine, Baylor Sports Medicine
Institute, Houston, Texas.

Jeffrey P. Koplan, M.D., M.P.H., President, Prudential
Center for Health Care Research, Atlanta, Georgia.

Andrea M. Kriska, Ph.D., M.S., Assistant Professor,
Department of Epidemiology, Graduate School of
Public Health, University of Pittsburgh, Pittsburgh,
Pennsylvania.

Barbara D. Latham, R.D., M.P.H., Public Health
Nutritionist, Division of Nutrition and Physical
Activity, National Center for Chronic Disease
Prevention and Health Promotion, Centers for
Disease Control and Prevention, Atlanta, Georgia.

I-Min Lee, M.B.B.S., Sc.D., Assistant Professor
of Medicine, Harvard Medical School, Boston,
Massachusetts.

ix


A Report of the Surgeon General

Elizabeth Lloyd, M.S., Statistician, Division of
Nutrition and Physical Activity, National Center for
Chronic Disease Prevention and Health Promotion,
Centers for Disease Control and Prevention, Atlanta,
Georgia.

Bess H. Marcus, Ph.D., Associate Professor of
Psychiatry and Human Behavior, Division of Behavior
and Preventive Medicine, Miriam Hospital and Brown
University School of Medicine, Providence, Rhode
Island.

DyannMatson-Koffman,Dr.P.H.,M.P.H., C.H.E.S.,
Public Health Educator, Division of Adult and
Community Health, National Center for Chronic
Disease Prevention and Health Promotion, Centers
for Disease ControI and Prevention, Atlanta,
Georgia.

Marion R. Nadel, Ph.D., Epidemiologist, Epidemiology
and Statistics Branch, Division of Cancer Prevention
and Control, National Center for Chronic Disease
Preventionand Health Promotion, Centers for Disease
Control and Prevention, Atlanta, Georgia.

Eva Obarzanek, Ph.D., M.P.H., R.D., Nutritionist,
National Heart, Lung, and Blood Institute, National
Institutes of Health, Bethesda, Maryland.

Christine M. Plepys, M.S., Health Statistician, Division
of Health Promotion Statistics, National Center for
Health Statistics, Centers for Disease Control and
Prevention, Hyattsville, Maryland.

Michael L. Pollock, Ph.D., Professor of Medicine,
Physiology and Health and Human Performance;
Director, Center for Exercise Science, University of
Florida, Gainesville, Florida.

Michael Pratt, M.D., M.P.H., Medical Epidemiologist,
Division of Nutrition and Physical Activity, National
Center for Chronic Disease Prevention and Health
Promotion, Centers for Disease Control and
Prevention, Atlanta, Georgia.

Paul T. Raford;M.D., M.P.H.,Special Assistant to the
Regional Health Administrator, Environmental
Justice Programs, Office of Public Health Science,
Region VIII, Department of Health and Human
Services, U.S. Public Health Service, Denver,
Colorado.

W. Jack Rejeski, Ph.D., Professor, Health and Sports
Science, Wake Forest University, Winston-Salem,
North Carolina.

Richard B. Rothenberg, M.D., M.P.H., F.A.C.P.,
Professor and Director, Preventive Medicine
Residency Program, Department of Family and
Preventive Medicine, Emory University School of
Medicine, Atlanta, Georgia.

Mary K. Serdula, M.D., M.P.H., Acting Branch Chief,
Chronic Disease Prevention Branch, Division of
Nutrition and Physical Activity, National Center for
Chronic Disease Prevention and Health Promotion,
Centers for Disease Control and Prevention, Atlanta,
Georgia.

Charlotte A. Schoenborn, M.P.H., Health Statistician,
National Center for Health Statistics, Centers for
Disease Control and Prevention, Hyattsville,
Maryland.

Denise G. Simons-Morton, M.D., Ph.D., Leader,
Prevention Scientific Research Group, DECA,
National Heart, Lung, and Blood Institute, National
Institutes of Health, Bethesda, Maryland.

Elaine J. Stone, Ph.D., M.P.H., Health Scientist
Administrator, Division of Epidemiology and Clinical
Applications, National Heart, Lung, and Blood
Institute, National Institutes of Health, Bethesda,
Maryland.

Marlene K. Tappe, Ph.D., Visiting Behavioral
Scientist, Division of Adolescent and School Health,
National Center for Chronic Disease Prevention and
Health Promotion, Centers for Disease Control and
Prevention, Atlanta, Georgia.

Wendell C. Taylor, Ph.D., M.P.H., Assistant Professor
of Behavioral Sciences, School of Public Health,
University of Texas Health Science Center at Houston,
Houston, Texas.

CharlesW. Warren, Ph.D., Statistician/Demographer,
Division of Adolescent and School Health, National
Center for Chronic Disease Prevention and Health
Promotion, Centers for Disease Control and
Prevention, Atlanta, Georgia.

Deborah R. Young, Ph.D., Assistant Professor of
Medicine, Division of Internal Medicine, The Johns
Hopkins School of Medicine, Baltimore, Maryland.

X


Physical Activity and Health

Senior Reviewers

Elizabeth A. Arendt, M.D., Associate Professor of
Orthopaedics, University of Minnesota, Minneapolis,
>jtnnesota. Member, President's Councilon Physical
Fitness and Sports.

Elsworth R. Buskirk, Ph.D., Professor of Applied
Physiology, Emeritus, Pennsylvania State University,
University Park, Pennsylvania.

B. Don Franks, Ph.D., Professor and Chair,
Department of Kinesiology, Louisiana State
University, Baton Rouge, Louisiana. Senior Program
Advisor, President's Council on Physical Fitness
and Sports.

\Villiam R. Harlan, M.D., Associate Director for
Disease Prevention, Office of the Director, National
Institutes of Health, Bethesda, Maryland.

William P. Morgan, Ed.D., Professor, Department of
Kincsiology, University of Wisconsin-Madison,
Madison, Wisconsin.

Ralph S. Paffenbarger,Jr., M.D., Dr.P.H., Professor of
Epidemiology (Retired-Active), Stanford University
School of Medicine, Stanford, California.

Russell R. Pate, Ph.D., Chairman, Department of
Escrcise Science, University of South Carolina,
cIolumbia,SouthCarolina. Represented the American
(:ollcge of Sports Medicine.

Roy J. Shephard, M.D., Ph.D., D.P.E., F.A.C.S.M.,
Professor EmeritusofApplied Physiology, University
of Toronto, Toronto, Canada.

Peer Reviewers

Barbara E. Ainsworth, Ph.D., M.P.H., Associate
Professor, Department of Epidemiology and
Biosratistics, Department ofExercise Science, School
of Public Health, University of South Carolina,
Columbia, South Carolina.

Tom Baranowski, Ph.D., Professor, Department of
Behavioral Science, University of Texas, M. D.
.-\nderson Cancer Center, Houston, Texas.

Oded Bar-Or, M.D., Professor of Pediatrics and
Director, Children's Exercise and Nutrition Centre,
McMaster University, Chedoke Hospital Division,
Hamilton, Ontario, Canada.

Charles B. Corbin, Ph.D., Professor, Department of
Exercise Science and Physical Education, Arizona
State University, Tempe, Arizona.

Kirk J. Cureton, Ph.D., Professor and Head,
Department of Exercise Science, University of
Georgia, Athens, Georgia.

Gail P. Dalsky, Ph.D., Assistant Professor ofMedicine
(in residence), University of Connecticut Health
Center, Farmington, Connecticut.

Nicholas A. DiNubile, M.D., Clinical Assistant
Professor, Department of Orthopaedic Surgery,
Hospital of the University of Pennsylvania; Chief,
Orthopaedic Surgery and Sports Medicine, Delaware
County Memorial Hospital, Drexel Hill, Pennsylvania.

BarbaraL. Drinkwater, Ph.D., Research Physiologist,
Pacific Medical Center, Seattle, Washington.

Andrea L. Dunn, Ph.D., Associate Director, Division
of Epidemiology and Clinical Applications, The
Cooper Institute for Aerobics Research, Dallas, Texas.

Leonard H. Epstein, Ph.D., Professor, Department of
Psychology, State University of New York at Buffalo,
Buffalo, New York.

Katherine M. Flegal, Ph.D., Senior Research
Epidemiologist, National Center for Health Statistics,
Centers for Disease Control and Prevention,
Hyattsville, Maryland.

Christopher D. Gardner, Ph.D., Research Fellow,
Stanford Center for Research in Disease Prevention,
Stanford University, Palo Alto, California.

Glen G. Gilbert, Ph.D., Professor and Chairperson,
Department of Health Education, University of
Maryland, College Park, Maryland.

Andrew P. Goldberg, M.D., Professor of Medicine
and Director, Division of Gerontology, University of
Maryland School of Medicine, Baltimore, Maryland.

John 0. Holloszy, M.D., Professor of Internal
Medicine, Washingtonuniversity SchoolofMedicine,
St. Louis, Missouri.

Melbourne F. Hovell, Ph.D., M.P.H., Professor of
Health Promotion; Director, Center for Behavioral
Epidemiology, Graduate School of Public Health,
College of Health and Human Services, San Diego
State University, San Diego, California.

xi


A Report of the Surgeon General

Caroline A. Macera, Ph.D., Director, Prevention
Center, School of Public Health, University of South
Carolina, Columbia, South Carolina.

JoAnn E. Manson, M.D., Dr.P.H., Co-Director of
Women's Health, Brigham and Women's Hospital,
Harvard Medical School, Boston, Massachusetts.

Jere H. Mitchell, M.D., Professor of Internal Medicine
and Physiology; Director, Harry S. Moss Heart Center,
University of Texas Southwestern Medical Center,
Dallas, Texas.

James R. Morrow, Jr., Ph.D., Professor and Chair,
Department of KHPR, University of North Texas,
Denton, Texas.

Neville Owen, Ph.D., Professor of Human Movement
Science, Deakin University, Melbourne, Australia.
Roberta J. Park, Ph.D., Professor of the Graduate
School, University of California, Berkeley, California.

Peter B. Raven, Ph.D., Professor and Chair,
Department of Integrative Physiology, University of
North Texas Health Science Center, Fort Worth,
Texas.

Judith G. Regensteiner, Ph.D., Associate Professor of
Medicine, University of Colorado Health Sciences
Center, Denver, Colorado.

Bruce G. Simons-Morton, Ed.D., M.P.H., Behavioral
Scientist, Prevention Research Branch, National
Institute of Child Health and Human Development,
National Institutes of Health, Bethesda, Maryland.

Denise G. Simons-Morton, M.D., Ph.D., Leader,
Prevention Scientific Research Group, DECA,
National Heart, Lung, and Blood Institute, National
Institutes of Health, Bethesda, Maryland.

James S. Skinner, Ph.D., Professor, Department of
Kinesiology, Indiana University, Bloomington,
Indiana.

Thomas Stephens, Ph.D., Principal, Thomas Stephens
and Associates, Ottawa, Canada.

Anita Stewart, Ph.D., Associate Professor in
Residence, University of California, San Francisco,
San Francisco, California.

C. Barr Taylor, M.D., Professor of Psychiatry,
Department of Psychiatry and Behavioral Sciences,
Stanford University School of Medicine, Stanford,
California.

Charles M. Tipton, Ph.D., F.A.C.S.M., Professor of
Physiology and Surgery, University of Arizona,
Tucson, Arizona.

Zung Vu Tran, Ph.D., Senior Research Scientist,
Center for Research in Ambulatory Health Care
Administration, Englewood, Colorado.

Other Contributors

Melissa M. Adams, Ph.D., Assistant Director for
Science, Division of Reproductive Health, National
Center for Chronic Disease Prevention and Health
Promotion, Centers for Disease Control and
Prevention, Atlanta, Georgia.

Indu Ahluwalia, M.P.H., Ph.D., EISOfficer, Division
of Nutrition and Physical Activity, National Center
for Chronic Disease Prevention and Health
Promotion, Centers for Disease Control and
Prevention, Atlanta, Georgia.

Betty A. Ballinger, Technical Information Specialist,
Technical Information and Editorial Services Branch,
National Center for Chronic Disease Prevention and
Health Promotion, Centers for Disease Control and
Prevention, Atlanta, Georgia.

Sandra W. Bart, Policy Coordinator, Office of the
Secretary, Executive Secretariat, Department of
Health and Human Services, Washington, D.C.

Mary Bedford, Proofreader, Cygnus Corporation,
Rockville, Maryland.

Caryn Bern, M.D., Medical Epidemiologist, Division
of Nutrition and Physical Activity, National Center
for Chronic Disease Prevention and Health
Promotion, Centers for Disease Control and
Prevention, Atlanta, Georgia.

Karil Bialostosky, M.S., Nutrition Fellow, National
Center for Health Statistics, Centers for Disease
Control and Prevention, Hyattsville, Maryland.

xii


Physical Activity and Health

Thomas E. Blakeney, Program Analyst, National
Center for Injury Prevention and Control, Centers
for Disease Control and Prevention, Atlanta,
Georgia.

Ronctte R. Briefel, Dr.P.H.. Nutrition Policy Advisor,
National Center for Health Statistics, Centers for
Disease Control and Prevention, Hyattsville,
htaryland.

L. Diane Clark, M.P.H., Public Health Nutritionist,
Division of Nutrition and Physical Activity, National
Ccntcr for Chronic Disease Prevention and Health
Promotion, Centers for Disease Control and
Prevention, Atlanta, Georgia.

jancl L. Coil' Ins, Ph.D., Chief, Surveillance and
Evaluation Research Branch, Division of Adolescent
and School Health, National Center for Chronic
Disease Prevention and Health Promotion, Centers
for Disease Control and Prevention, Atlanta,
Georgia.

Janet B. Croft, Ph.D.,Epidemiogist,DivisionofAdult
;tnd Community Health, National Center for Chronic
Discasc Prevention and Health Promotion, Centers
for Disease Control and Prevention, Atlanta,
Georgia.

Ann M. Cronin, Program Analyst, National Institute
for Occupational Safety and Health, Centers for
Discase Control and Prevention, Atlanta, Georgia.

(iail A. Cruse, M.L.I.S., Technical Information
Specialist, Technical Information and Editorial
Scrviccs Branch, National Center for Chronic Disease
Prcventionand Health Promotion, Centers for Disease
Control and Prevention, Atlanta, Georgia.

John M. Davis, M.P.A., R.D., Public Health Analyst,
Division of Nutrition and Physical Activity, National
Center for Chronic Disease Prevention and Health
Promotion, Centers for Disease Control and
Prevention, Atlanta, Georgia.

Earl S. Ford, M.D., M.P.H., Senior Scientist, Division
of Nutrition and Physical Activity, National Center
for Chronic Disease Prevention and Health
Promotion, Centers for Disease Control and
Prevention, Atlanta, Georgia.

Christine S. Fralish, M.L.I.S., Chief, Technical
Information and Editorial Services Branch, National
Center for Chronic Disease Prevention and Health
Promotion, Centers for Disease Control and
Prevention, Atlanta, Georgia.

Emma L. Frazier, Ph.D., Mathematical Statistician,
Division of Diabetes Translation, National Center
for Chronic Disease Prevention and Health
Promotion, Centers for Disease Control and
Prevention, Atlanta, Georgia.

Deborah A. Galuska, M.P.H., Ph.D., EIS Fellow,
Division of Nutrition and Physical Activity, National
Center for Chronic Disease Prevention and Health
Promotion, Centers for Disease Control and
Prevention, Atlanta, Georgia.

Dinamarie C. Garcia, M.P.H., C.H.E.S., Intern,
Division of Nutrition and Physical Activity, National
Center for Chronic Disease Prevention and Health
Promotion, Centers for Disease Control and
Prevention, Atlanta, Georgia.

Linda S. Geiss, M.A., Health Statistician, Division of
Diabetes Translation, National Center for Chronic
Disease Prevention and Health Promotion, Centers
for Disease Control and Prevention, Atlanta, Georgia.

Wayne H. Giles, M.D., M.S., Epidemiologist,
Cardiovascular Health Section, Division of Adult
and Community Health, National Center for Chronic
Disease Prevention and Health Promotion, Centers
for Disease Control and Prevention, Atlanta, Georgia.

Kay Sissions Golan, Public Affairs Specialist, Office
of Communication (proposed), Centers for Disease
Control and Prevention, Atlanta, Georgia.

Betty H. Haithcock, Editorial Assistant, Technical
Information and Editorial Services Branch, National
Center for Chronic Disease Prevention and Health
Promotion, Centers for Disease Control and
Prevention, Atlanta, Georgia.

Helen P. Hankins, Writer-Editor, Technical
Information and Editorial Services Branch, National
Center for Chronic Disease Prevention and Health
Promotion, Centers for Disease Control and
Prevention, Atlanta, Georgia.

. . .
XIII


A Report of the Surgeon General

Rita Harding, Graphic Designer, Cygnus Corporation,
Rockville, Maryland.

William A. Harris, M.M., Computer Specialist,
Division of Adolescent and School Health, National
Center for Chronic Disease Prevention and Health
Promotion, Centers for Disease Control and
Prevention, Atlanta, Georgia.

Charles G. Helmick, III, M.D., Division of Adult and
Community Health, National Center for Chronic
Disease Prevention and Health Promotion, Centers
for Disease Control and Prevention, Atlanta, Georgia.

Elizabeth L. Hess, Technical Editor, Cygnus
Corporation, Rockville, Maryland.

Mary Ann Hill, M.P.P., Director of Communications,
President's Council on Physical Fitness and Sports,
Washington, D.C.

Thomya L. Hogan, Proofreader, Cygnus Corporation,
Rockville, Maryland.

Judy F. Horne, Technical Information Specialist,
Technical Information and Editorial ServicesBranch,
National Center for Chronic Disease Prevention and
Health Promotion, Centers for Disease Control and
Prevention, Atlanta, Georgia.

Catherine A. Hutsell, M.P.H., Public Health Educator,
Division of Adult and Community Health, National
Center for Chronic Disease Prevention and Health
Promotion, Centers for Disease Control and
Prevention, Atlanta, Georgia.

Robert Irwin, Special Assistant, Office of the Director,
Centers for Disease Control and Prevention,
Washington, D.C.

Sandra E. Jewell, MS., Statistician, Division of
Nutrition and Physical Activity, National Center for
Chronic Disease Prevention and Health Promotion,
Centers for Disease Control and Prevention, Atlanta,
Georgia.

Loretta G. Johnson, Secretary, Division of Nutrition
and Physical Activity, National Center for Chronic
Disease Prevention and Health Promotion, Centers
for Disease Control and Prevention, Atlanta, Georgia.

Deborah A. Jones, Ph.D., Epidemiologist, Division
of Nutrition and Physical Activity, National Center
for Chronic Disease Prevention and Health
Promotion, Centers for Disease Control and
Prevention, Atlanta, Georgia.

Wanda K. Jones, M.P.H., Dr.P.H., Associate Director
for Women's Health, Office of Women's Health,
Centers for Disease Control and Prevention, Atlanta,
Georgia.

Robert E. Keaton, Consultant, Cygnus Corporation,
Rockville, Maryland.

Delle B. Kelley, Technical Information Specialist,
Technical Information and Editorial ServicesBranch,
National Center for Chronic Disease Prevention and
Health Promotion, Centers for Disease Control and
Prevention, Atlanta, Georgia.

Mescal J. Knighton, Writer-Editor, Technical
Information and Editorial Services Branch, National
Center for Chronic Disease Prevention and Health
Promotion, Centers for Disease Control and
Prevention, Atlanta, Georgia.

Sarah B. Knowlton, J.D., M.S.W., Attorney Advisor,
Office of the General Council, Centers for Disease
Control and Prevention, Atlanta, Georgia.

FredKroger,ActingDirector,HealthCommunication,
Office of Communication (proposed), Centers for
Disease Control and Prevention, Atlanta, Georgia.

Sarah A. Kuester, M.P.H., R.D., Public Health
Nutritionist, Division of Nutrition and Physical
Activity, National Center for Chronic Disease
Prevention and Health Promotion, Centers for Disease
Control and Prevention, Atlanta, Georgia.

Becky H. Lankenau, M.S., R.D., M.P.H., Dr.P.H.,
Public Health Nutritionist, Division of Nutrition and
Physical Activity, National Center for Chronic Disease
Prevention and Health Promotion, Centers for Disease
Control and Prevention, Atlanta, Georgia.

Nancy C. Lee, M.D., Associate Director for Science,
Division of Cancer Prevention and Control, National
Center for Chronic Disease Prevention and Health
Promotion, Centers for Disease Control and
Prevention, Atlanta, Georgia.

xiv


Physical Activity and Health

Leandris C. Liburd, M.P.H., Public Health Educator,
Division of Diabetes Translation, National Center
for Chronic Disease Prevention and Health
Promotion, Centers for Disease Control and
Prevention, Atlanta, Georgia.

Richard Lowry, M.D., M.S., Medical Epidemiologist,
Division of Adolescent and School Health, National
Center for Chronic Disease Prevention and Health
Promotion, Centers for Disease Control and
Prevention, Atlanta, Georgia.

Salvatore J. Lucido, M.P.A., Program Analyst,
National Center for Chronic Disease Prevention and
Health Promotion, Centers for Disease Control and
Prevention, Atlanta,, Georgia.

Gene W. Matthews, Esq., Legal Advisor to CDC and
ATSDR, Office of the General Council, Centers for
Disease Control and Prevention, Atlanta, Georgia.

Urcnda W. Mazzocchi, M.S.L.S., Technical
Information Specialist, Technical Information and
Editorial Services Branch, National Center for
Chronic Disease Prevention and Health Promotion,
Ccntcrs for Disease Control and Prevention, Atlanta,
(icorgia.

Sharon McDonnell, M.D., M.P.H., Medical
Ilpidcmiologist, Division of Nutrition and Physical
:\ctivity, National Center for Chronic Disease
I'rcvcntionand Health Promotion, Centers for Disease
Control and Prevention, Atlanta, Georgia.

Michael A. McGeehin, Ph.D., M.S.P.H., Chief, Health
9udics Branch, Division of Environmental Hazards
and Health Effects, National Center for Environmental
1 icalth, Centers for Disease Control and Prevention,
Atlanta, Georgia.

ZU~UO Mei, M.D., M.P.H. Visiting Scientist, Division
of Nutrition and Physical Activity, National Center
for Chronic Disease Prevention and Health
Promotion, Centers for Disease . Control and
Prcvcntion, Atlanta, Georgia.

lames M. Mendlein, Ph.D., Epidemiologist, Division
of Nutrition and Physical Activity, National Center
for Chronic Disease Prevention and Health
Promotion, Centers for Disease Control and
frcvenlion, Atlanta, Georgia.

Robert K. Merritt, M.A., Behavioral Scientist, Office
on Smoking and Health, National Center for Chronic
,Disease Prevention and Health Promotion, Centers
for Disease Control and Prevention, Atlanta,
Georgia.

Gaylon D. Morris, M.P.P., Program Analyst, Office
of Program Planning and Evaluation, Centers for
Disease Control and Prevention, Atlanta, Georgia.

Melba Morrow, M.A., Division Manager, The Cooper
Institute for Aerobics Research, Dallas, Texas.

Marion R. Nadel, Ph.D., Epidemiologist, Division of
Cancer Prevention and Control, National Center for
Chronic Disease Prevention and Health Promotion,
Centers for Disease Control and Prevention, Atlanta,
Georgia.

David E. Nelson, M.D., M.P.H., Medical Officer,
Division of Adult and Community Health, National
Center for Chronic Disease Prevention and Health
Promotion, Centers for Disease Control and
Prevention, Atlanta, Georgia.

Reba A. Norman, M.L.M., Technical Information
Specialist, Technical Information and Editorial
Services Branch, National Center for Chronic Disease
Prevention andHealth Promotion, Centers for Disease
Control and Prevention, Atlanta, Georgia.

Ward C. Nyholm, Graphic Designer, Cygnus
Corporation, Rockville, Maryland.

Stephen M. Ostroff, M.D., Associate Director for
Epidemiologic Science, National Center for Infectious
Diseases, Centers for Disease Control and Prevention,
Atlanta, Georgia.

Ibrahim Parvanta, MS., Acting Deputy Chief,
Maternal and Child Health Branch, Division of
Nutrition and Physical Activity, National Center for
Chronic Disease Prevention and Health Promotion,
Centers for Disease Control and Prevention, Atlanta,
Georgia.

Terry F. Pechacek, Ph.D., Visiting Scientist, Office
on Smoking and Health, National Center for Chronic
Disease Prevention and Health Promotion, Centers
for Disease Control and Prevention, Atlanta, Georgia.

xv


A Report of the Surgeon General

Geraldine S. Perry, Dr.P.H., Epidemiologist, Division
of Nutrition and Physical Activity, National Center
for Chronic Disease Prevention and Health
Promotion, Centers for Disease Control and
Prevention, Atlanta, Georgia.

Todd M. Phillips, M.S., Deputy Project Director,
Cygnus Corporation, Rockville, Maryland.

Audrey L. Pinto, Writer-Editor, Technical
Information and Editorial Services Branch, National
Center for Chronic Disease Prevention and Health
Promotion, Centers for Disease Control and
Prevention, Atlanta, Georgia.

Kenneth E. Powell, M.D., M.P.H., Associate Director
for Science, Division of Violence Prevention, National
Center for Injury Prevention and Control, Centers
for Disease Control and Prevention, Atlanta,Georgia.

Julia H. Pruden, M.Ed., R.D., Public Health
Nutritionist, Division of Nutrition and Physical
Activity, National Center for Chronic Disease
Prevention and Health Promotion, Centers for Disease
Control and Prevention, Atlanta, Georgia.

David C. Ramsey, M.P.H., Public Health Educator,
Division of Nutrition and Physical Activity, National
Center for Chronic Disease Prevention and Health
Promotion, Centers for Disease Control and
Prevention, Atlanta, Georgia.

Brenda D. Reed, Secretary, Division of Adult and
Community Health, National Center for Chronic
Disease Prevention and Health Promotion, Centers
for Disease Control and Prevention, Atlanta, Georgia.

Susan A. Richardson, Writer-Editor, Cygnus
Corporation, Rockville, Maryland.

Christopher Rigaux, Project Director, Cygnus
Corporation, Rockville, Maryland.

Angel Rota, Program Analyst, National Center for
Chronic Disease Prevention and Health Promotion,
Centers for Disease Control and Prevention, Atlanta,
Georgia.

Cheryl V. Rose, Computer Specialist, Division of
Health Promotion Statistics, National Center for
Health Statistics,. Centers for Disease Control and
Prevention, Hyattsville, Maryland.

Patti Schwartz, Graphic Designer, Cygnus Corporation,
Rockville, Maryland.

Bettylou Sherry, Ph.D., Epidemiologist, Maternal
and Child Health Branch, Division of Nutrition and
Physical Activity, National Center for Chronic Disease
Prevention and Health Promotion, Centers for Disease
Control and Prevention, Atlanta, Georgia.

Margaret Leavy Small, Behavioral Scientist, Division
of Adolescent and School Health, National Center
for Chronic Disease Prevention and Health
Promotion, Centers for Disease Control and
Prevention, Atlanta, Georgia

Joseph B. Smith, Senior Project Officer, Disabilities
Prevention Program, National Center for
Environmental Health, Centers for Disease Control
and Prevention, Atlanta, Georgia.

Terrie D. Sterling, Ph.D., Research Psychologist,
Division of Adult and Community Health, National
Center for Chronic Disease Prevention and Health
Promotion, Centers for Disease Control and
Prevention, Atlanta, Georgia.

Emma G. Stupp, M.L.S., Technical Information
Specialist, Technical Information and Editorial
ServicesBranch, National Center for Chronic Disease
Prevention and Health Promotion, Centers for Disease
Control and Prevention, Atlanta, Georgia.

William I. Thomas, M.L.I.S., Technical Information
Specialist, Technical Information and Editorial
Services Branch, National Center for Chronic Disease
Prevention and Health Promotion, Centers for Disease
Control and Prevention, Atlanta, Georgia.

Patricia E. Thompson-Reid, M.A.T., M.P.H.,
Program Development Consultant/Community
Interventionist, Division of Diabetes Translation,
National Center for Chronic Disease Prevention and
Health Promotion, Centers for Disease Control and
Prevention, Atlanta, Georgia.

Jenelda Thornton, Staff Specialist, National Center
for Chronic Disease Prevention and Health
Promotion, Centers for Disease Control and
Prevention, Atlanta, Georgia.

xvi


Physical Activity and Health

Nancy B. Watkins, M.P.H., Health Education
Specialist, Division of Adult and Community Health,
National Center for Chronic Disease Prevention and
Health Promotion, Centers for Disease Control and
Prevention, Atlanta, Georgia.

Howell Wechsler, Ed.D., M.P.H., Health Education
Research Scientist, Division of Adolescent and School
Health, National Center for Chronic Disease
Preventionand Health Promotion, Centers for Disease
Control and Prevention, Atlanta, Georgia.

Julie C. Will, Ph.D., M.P.H., Epidemiologist, Division
of Nutrition and Physical Activity, National Center
for Chronic Disease Prevention and Health
Promotion, Centers for Disease Control and
Prevention, Atlanta, Georgia.

Lynda S. Williams, Program. Analyst, National
Center for Chronic Disease Prevention and Health
Promotion, Centers for Disease Control and
Prevention, Atlanta, Georgia.

David F. Williamson, Ph.D., Acting Director,
Division of Diabetes Translation, National Center
for Chronic Disease Prevention and Health
Promotion, Centers for Disease Control and
Prevention, Atlanta, Georgia.

Stephen W. Wyatt, D.M.D., M.P.H., Director, Division
of Cancer Prevention and Control, National Center
for Chronic Disease Prevention and Health
Promotion, Centers for Disease Control and
Prevention, Atlanta, Georgia,

Matthew M. Zack, M.D.; M.P.H., Medical
Epidemiologist, Division of Adult and Community
Health, National Center for Chronic Disease
Prevention andHealth Promotion, Centers for Disease
Control and Prevention, Atlanta, Georgia.

xvii


PHYSICAL ACTIVITV AND HEALTH

Chapter 1: Introduction, Summary, and Chapter Conclusions   ....................... 1
Chapter 2: Historical Background, Terminology, Evolution of Recommendations
andbleasurement   .......................................................... 9

Western Historical Perspective  ............................................... .12
Terminology of Physical Activity, Physical Fitness, and Health  ..................... .2O
Evolution of Physical Activity Recommendations  .................................. 22
Summary of Recent Physical Activity Recommendations ........................... .28
Measurement of Physical Activity, Fitness, and Intensity  .......................... .29
Chapter 3: Physiologic Responses and Long-Term Adaptations to Exercise  ............ .61
Physiologic Responses to Episodes of Exercise  .................................. .61
Long-Term Adaptations to Exercise Training .................................... .67
Maintenance, Detraining, and Prolonged Inactivity  ............................... .71
Special Considerations  ..................................................... .73

Chapter 4: The Effects of Physical Activity on Health and Disease  ................... .81
Overall Mortality  ........................................................... .85

  Cardiovascular Diseases  .................................................... .87

  Cancer ................................................................ ..112
Non-Insulin-Dependent Diabetes Mellitus ..................................... .125

  Osteoarthritis                                                .129
                ................. , ..........................................
  Osteoporosis ........................................................... ..13 0
Obcsity..................................................................13 3
  McntalHealth .......................................................... ..13 5
  Health-Related Quality of Life ............................................... .141
  Adverse Effects of Physical Activity  .......................................... .142
  Occurrence of Adverse Effects  .............................................. .144
  Nature of the Activity/Health Relationship  ..................................... .144

Cllaptcr 5: Patterns and Trends in Physical Activity  ............................... 173
  Physical Activity among Adults in the United States  ............................. .177
Physical Activity among Adolescents and Young Adults in the United States  ........... 186

Chapter 6: Understanding and Promoting Physical Activity   ....................... ,209
  Theories and Models Used in Behavioral and Social Research on
   PhysicalActivity.. .................................................... ..211
  Behavioral Research on Physical Activity among Adults  .......................... .215
Behavioral Research on Physical Activity among Children and Adolescents  ........... .234
  Promising Approaches, Barriers, and Resources  ................................. .243
List of Tables and Figures   ................................................... .261

Index  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...265


        CHAPTER 1
INTRODUCTION, SUMMARY,
AND CHAPTER CONCLUSIONS

Contents

Introduction  ................................................................. 3
Development of the Report  ................................................... 3
MajorConclusions  ......................................................... 4

Summary . .._................................................,............._ 4

Chapter Conclusions  .......................................................... 6
Chapter 2: Historical Background and Evolution of Physical Activity Recommendations  . . 6
Chapter 3: Physiologic Responses and Long-Term Adaptations to Exercise  ............. 7
Chapter 4: The Effects of Physical Activity on Health and Disease  .................... 7
Chapter 5: Patterns and Trends in Physical Activity  ............................... 8
Chapter 6: Understanding and Promoting Physical Activity  ......................... 8


CHAPTER 1

htroduction

T his is the first Surgeon General's report to ad-
dress physical activity and health. The main
message of this report is that Americans can substan-
tially improve their health and quality of life by
including moderate amounts of physical activity in
their daily lives. Health benefits from physical activ-
ity arc thus achievable for most Americans, includ-
ing those who may dislike vigorous exercise and
those who may have been previously discouraged by
rhc difficulty of adhering to a program of vigorous
cscrcise. For those who are alreadyachievingregular
modcrate amounts of activity, additional benefits
c.an bc gained by further increases in activity level.
This report grew out of an emerging consensus
:~mong epidemiologists, experts in exercise science,
;1nc1 health professionals that physical activity need
not be of vigorous intensity for it to improve health.
Morcovcr, health benefits appear to be proportional
10 amount of activity; thus, every increase in activity
~lds some benefit. Emphasizing the amount rather
lhan the intensity of physical activity offers more
options for people to select from in incorporating
physical activity into their daily lives. Thus, a mod-
crate amount of activity can be obtained in a 30-
minute brisk walk, 30 minutes of lawn mowing or
raking leaves, a 1%minute run, or 45 minutes of
playing volleyball, and these activities can be varied
from day to day. It is hoped that this different
elnphasis on moderate amounts of activity, and the
ncsibility to vary activities according to personal
prcfcrcnce and life circumstances, will encourage
more people to make physical activity a regular and
sustainable part of their lives.

The information in this report summarizes a
diverse literature from the fields of epidemiology,
cscrcisc physiology, medicine, and the behavioral
sciences. The report highlights what is known about

INTRODUCTION, SUMMARY,
AND CHAPTER CONCLUSIONS

physical activity and health; as well as what is being
learned about promoting phjrsical activity among
adults and young people.

Development of the Report
In July 1994, the Office of the Surgeon General
authorized the Centers for Disease Control and Pre-
vention (CDC) to serve as lead agency for preparing
the first Surgeon General's report on physical activity
and health. The CDC was joined in this effort by the
President's Council on Physical Fitness and Sports
(PCPFS) as a collaborative partner representing the
Office of the Surgeon General. Because of the wide
interest in the health effects of physical activity, the
report was planned collaboratively with representa-
tives from the Office of the Surgeon General, the
Office of Public Health and Science (Office of the
Secretary), the Office of Disease Prevention (Na-
tional Institutes of Health [NIH]), and the following
institutes from the NIH: the National Heart, Lung,
and Blood Institute; the National Institute of Child
Health and Human Development; the National Insti-
tute of Diabetes and Digestive and Kidney Diseases;
and the National Institute of Arthritis and Muscu-
loskeletal and Skin Diseases. CDC's nonfederal part-
ners-indluding the American Alliance for Health,
Physical Education, Recreation, and Dance; the
American College of Sports Medicine; and the Ameri-
can Heart Association-provided consultation
throughout the development process.
The major purpose of this report is to summarize
the existing literature on the role of physical activity in
preventing disease and on the status of interventions to
increase physical activity. Any report on a topic this
broad must restrict its scope to keep its message clear.
This report focuses on disease prevention and there-
fore does not include the considerable body of evi-
dence on the benefits of physical activity for treatment or


Physical Activity and Health

rehabilitation after disease has developed. This report
concentrates on endurance-type physical activity (ac-
tivity involving repeated use of large muscles, such as
in walking or bicycling) because the health benefits of
this type of activity have been extensively studied. The
importance of resistance exercise (to increase muscle
strength, such as by lifting weights) is increasingly
being recognized as a means to preserve and enhance
muscular strength and endurance and to prevent falls
and improve mobility in the elderly. Some promising
findings on resistance exercise are presented here, but
a comprehensive review of resistance training is be-
yond the scope of this report. In addition, a review of the
special concerns regarding physical activity for preg-
nant women and for people with disabilities is not
undertaken here, although these important topics de-
serve more research and attention.
Finally, physical activity is only one of many every-
day behaviors that affect health. In particular, nutri-
tional habits are linked to some of the same aspects of
health as physical activity, and the two may be related
lifestyle characteristics. This report deals solely with
physical activity; a Surgeon General's Report on Nutri-
tion and Health was published in 1988.
  Chapters 2 through 6 of this report address dis-
tinct areas of the current understanding of physical
activity and health. Chapter 2 offers a historical per-
spective: after outlining the history of belief and
knowledge about physical activity and health, the
chapter reviews the evolution and content of physical
activity recommendations. Chapter 3 describes the
physiologic responses to physical activity-both the
immediate effects of a single episode of activity and the
long-term adaptations to a regular pattern of activity.
The evidence that physical activity reduces the risk of
cardiovascular and other diseases is presented in
Chapter 4. Data on patterns and trends of physical
activity in the U.S. population are the focus of Chapter
5. Lastly, Chapter 6 examines efforts to increase
physical activity and reviews ideas currently being
proposed for policy and environmental initiatives.

Major Conclusions
1. People of all ages, both male and female, benefit
from regular physical activity.
2. Significant health benefits can be obtained by
including a moderate amount of physical activity
(e.g., 30 minutes of brisk walking or raking

3.

4.

5.

6.

7.

leaves, 15 minutes of running, or 45 minutes of
playing volleyball) on most, if not all, days of the
week. Through a modest increase in daily activity,
most Americans can improve their health and
quality of life.

Additional health benefits can be gained through
greater amounts of physical activity. People who
can maintain a regular regimen of activity that is
of longer duration or of more vigorous intensity
are likely to derive greater benefit.
Physical activity reduces the. risk of premature
mortality in general, and of coronary heart dis-
ease, hypertension, colon cancer, and diabetes
mellitus in particular. Physical activity also im-
proves mental health and is important for the
health of muscles, bones, and joints.
More than 60 percent of American adults are not
regularly physically active. In fact, 25 percent of
all adults are not active at all.
Nearly half of American youths 12-21 years of age
are not vigorously active on a regular basis. More-
over, physical activity declines dramatically dur-
ing adolescence.

Daily enrollment in physical education classes
has declined among high school students from 42
percent in 1991 to 25 percent in 1995.

8. Research on understanding and promotingphysi-
cal activity is at an early stage, but some interven-
tions to promote physical activity through schools,
worksites, and health care settings have been
evaluated and found to be successful.

Summary

The benefits of physical activity have been extolled
throughout western history, but it was not until the
second half of this century that scientific evidence
supporting these beliefs began to accumulate. By the
1970s enough information was available about the
beneficial effects of vigorous exercise on cardiorespi-
ratory fitness that the American College of Sports
Medicine (ACSM), the American Heart Association
(AHA), and other national organizations began issu-
ing physical activity recommendations to the public.
These recommendations generally focused on car-
diorespiratory endurance and specified sustained
periods of vigorous physical activity involving large
muscle groups and lasting at least 20 minutes on 3 or

4


more days per week. As understanding of the ben-
efitsoflessvigorousactivitygrew, recommendations
followed suit. During the past few years, the ACSM,
the CDC, the AHA, the PCPFS, and the NIH have all
recommended regular, moderate-intensity physical
activity as an option for those who get little or no
exercise. The Healthy Peopfe2OOOgoals for the nation's
health have recognized the importance of physical
activity and have included physical activity goals.
The 1995 Dietary Guidelinesfor Americans, the basis
of the federal government's nutrition-related pro-
grams, included physical activity guidance to main-
tain and improve weight-30 minutes or more of
moderate-intensity physical activity on all, or most,
days of the week.

Underpinning such recommendations is a grow-
ing understanding of how physical activity affects
physiologic function. The body-responds to physical
activity in ways that have important positive effects
on musculoskeletal, cardiovascular, respiratory, and
endocrine systems. These changes are consistent
with a number of health benefits, including a re-
duced risk of premature mortality and reduced risks
of coronary heart disease, hypertension, colon can-
cer, and diabetes mellitus. Regular participation in
physical activity also appears to reduce depression
and anxiety, improve mood, and enhance ability to
perform daily tasks throughout the life span.
The risks associated with physical activity must
also be considered. The most common health prob-
lems that have been associated with physical activity
are musculoskeletal injuries, which can occur with
excessive amounts of activity or with suddenly be-
ginning an activity for which the body is not condi-
tioned. Much more serious associated health
problems (i.e., myocardial infarction, sudden death)
are also much rarer, occurring primarily among
sedentary people with advanced atherosclerotic dis-
ease who engage in strenuous activity to which they
are unaccustomed. Sedentary people, especially those
with preexisting health conditions, who wish to
increase their physical activity should therefore
gradually build up to the desired level of activity.
Even among people who are regularly active, the risk
of myocardial infarction or sudden death is some-
what increased during physical exertion, but their
overall risk of these outcomes is lower than that
among people who are sedentary.

Introduction, Summary, and Chapter Conclusions

  Research on physical activity continues to evolve.
This report includes both well-established findings
and newer research results that await replication and
amplification. Interest has been developing in ways
to differentiate between the various characteristics of
physical activity that improve health. It remains to be
determined how the interrelated characteristics of
amount, intensity, duration, frequency, type, and
pattern of physical activity are related to specific
health or disease outcomes.

Attention has been drawn recently to findings
from three studies showing `that cardiorespiratory
fitness gains are similar when physical activity oc-
curs in several short sessions (e.g., 10 minutes) as
when the same total amount and intensity of activity
occurs in one longer session (e.g., 30 minutes).
Although, strictly speaking, the health benefits of
such intermittent activity have not yet been demon-
strated, it is reasonable to expect them to be similar
to those of continuous activity. Moreover, for people
who are unable to set aside 30 minutes for physical
activity, shorter episodes are clearly better than none.
Indeed, one study has shown greater adherence to a
walking program among those walking several times
per day than among those walking once per day,
when the total amount of walking time was kept the
same. Accumulating physical activity over the course
of the day has been included in recent recommenda-
tions from the CDC and ACSM, as well as from the
NIH Consensus Development Conference on Physi-
cal Activity and Cardiovascular Health.
Despite common knowledge that exercise is
healthful, more than 60 percent of American adults
are not regularly active, and 25 percent of the adult
population are not active at all. Moreover, although
many people have enthusiastically embarked on vig-
orous exercise programs at one time or another, most
do not sustain their participation. Clearly, the pro-
cesses of developing and maintaining healthier hab-
its are as important to study as the health effects of
these habits.

The effort to understand how to promote more
active lifestyles is of great importance to the health of
this nation. Although the study of physical activity
determinants and interventions is at an early stage,
effective programs to increase physical activity have
been carried out in a variety of settings, such as
schools, physicians' offices, and worksites. Determin-
ing the most effective and cost-effective intervention

5


Physical Activity and Health

approaches is a challenge for the future. Fortu-
nately, the United States has skilled leadership and
institutions to support efforts to encourage and
assist Americans to become more physically active.
Schools, community agencies, parks, recreational
facilities, and health clubs are available in most
communities and can be more effectively used in
these efforts.

School-based interventions for youth are particu-
larly promising, not only for their potential scope-
almost all young people between the ages of 6 and 16
years attend school-but also for their potential im-
pact. Nearly half of young people 12-21 years of age
are not vigorously active; moreover, physical activity
sharply declines during adolescence. Childhood and
adolescence may thus be pivotal times for preventing
sedentary behavior among adults by maintaining the
habit of physical activity throughout the school years.
School-based interventions have been shown to be
successful in increasing physical activity levels. With
evidence that success in this arena is possible, every
effort should be made to encourage schools to require
daily physical education in each grade and to promote
physical activities that can be enjoyed throughout life.
  Outside the school, physical activity programs
and initiatives face the challenge of a highly techno-
logical society that makes it increasingly convenient
to remain sedentary and that discourages physical
activity in both obvious and subtle ways. To increase
physical activity in the general population, it may be
necessary to go beyond traditional efforts. This re-
port highlights some concepts from community
initiatives that are being implemented around the
country. It is hoped that these examples will spark
new public policies and programs in other places as
well. Special efforts will also be required to meet the
needs of special populations, such as people with
disabilities, racial and ethnic minorities, people with
low income, and the elderly. Much more informa-
tion about these important groups w-ill be necessary
to develop a truly comprehensive national initiative
for better health through physical activity. Chal-
lenges for the future include identifying key deter-
minants of physically active lifestyles among the
diverse populations that characterize the United
States (including special populations, women, and
young people) and using this information to design
and disseminate effective programs.

Chapter Conclusions
Chapter 2: Historical Background and
Evolution of Physical Activity
Recommendations

1.

Physical activity for better health and well-being
has been an important theme throughout much
of western history.

2.

Public health recommendations have evolved
from emphasizing vigorous activity for cardio-
respiratory fitness to including the option of
moderate levels of activity for numerous health
benefits.

3.

Recommendations from experts agree that for
better health, physical activity should be per-
formed regularly. The most recent recommenda-
tions advise people of all ages to include a
minimum of 30 minutes of physical activity of
moderate intensity (such as brisk walking) on
most, if not all, days of the week. It is also
acknowledged that for most people, greater health
benefits can be obtained by engaging in physical
activity of more vigorous intensity or of longer
duration.

4.

Experts advise previously sedentary people em-
barking on a physical activity program to start
with short durations of moderate-intensity activ-
ity and gradually increase the duration or inten-
sity until the goal is reached.

5.

6

Experts advise consulting with a physician before
beginning a new physical activity program for
people with chronic diseases, such as cardiovas-
cular disease and diabetes mellitus, or for those
who are at high risk for these diseases. Experts
also advise men over age 40 and women over age
50 to consult a physician before they begin a
vigorous activity program.
Recent recommendations from experts also sug-
gest that cardiorespiratory endurance activity
should be supplemented with strength-devel-
oping exercises at least twice per week for
adults, in order to improve musculoskeletal
health, maintain independence in performing
the activities of daily life, and reduce the risk of
falling.

6


Introduction, Summary, and Chapter Conclusions

Chapter 3: Physiologic Responses and Long-
Term Adaptations to Exercise

Physical activity has numerous beneficial physi-
ologic effects. Most widely appreciated are its
effects on the cardiovascular and musculoskel-
eta1 systems, but benefits on the functioning of
metabolic, endocrine, and immune systems are
also considerable.

Many of the beneficial effects of exercise training-
from both endurance and resistance activities-
diminish within 2 weeks if physical activity is
substantially reduced, and effects disappear within
2 to 8 months if physical activity is not resumed.

,. People of all ages, both male and female, undergo
beneficial physiologic adaptations to physical
activity.

Chapter 4: The Effects of Physical Activity
on Health and Disease

Overall Mortality
I. Higher levels of regular physical activity are asso-
ciated with lower mortality rates for both older
and younger adults.
2. Even those who are moderately active on a regu-
lar basis have lower mortality rates than those
who are least active.

Cardiovascular Diseases
1. Regular physical activity or cardiorespiratory fit-
ncss decreases the risk of cardiovascular disease
mortality in general and of coronary heart disease
mortality in particular. Existing data are not con-
clusive regarding a relationship between physical
activity and stroke.

1. The level of decreased risk of coronary heart
disease attributable to regular physical activity is
similar to that of other lifestyle factors, such as
keeping free from cigarette smoking.
3. Regular physical activity prevents or delays the
development of high blood pressure, and exer-
cise reduces blood pressure in people with
hypertension.

Cancer

1. Regular physical activity is associated with a
decreased risk of colon cancer.

2.








3.

There is no association between physical activity
and rectal cancer. Data are too sparse to draw
conclusions regarding a relationship between
physical activity and endometrial, ovarian, or
testicular cancers.

Despite numerous studies on the subject, exist-
ing data are inconsistent regarding an association
between physical activity and breast or prostate
cancers.

Non-Insulin-Dependent Diahefes Mellifus
1.) Regular physical activity lowers the risk of devel-
oping non-insulin-dependent diabetes mellitus.

Osteoarthritis

1. Regular physical activity is necessary for main-
taining normal muscle strength, joint structure,
and joint function. In the range recommended for
health, physical activity is not associated with
joint damage or development of osteoarthritis
and may be beneficial for many people with
arthritis.

2. Competitive athletics may be associated with the
development of osteoarthritis later in life, but
sports-related injuries are the likely cause.

Osteoporosis
1.






2.

Weight-bearing physical activity is essential for
normal skeletal development during childhood
and adolescence and for achieving and maintain-
ing peak bone mass in young adults.
It is unclear whether resistance- or endurance-
type physical activity can reduce the accelerated
rate of bone loss in postmenopausal women in the
absence of estrogen replacement therapy.

Falling

1. There is promising evidence that strength train-
ing and other forms of .exercise in older adults
preserve the ability to maintain independent liv-
ing status and reduce the risk of falling.

Obesif y
1. Low levels of activity, resulting in fewer kilocalo-
ries used than consumed, contribute to the high
prevalence of obesity in the United States.
2. Physical activity may favorably affect body fat
distribution.


Physical Activity and Health

Mental Health

1. Physical activity appears to relieve symptoms of
depression and anxiety and improve mood.
2. Regular physical activity may reduce the risk of
developing depression, although further research
is needed on this topic.

Health-Related Qualify of Life
1. Physical activity appears to improve health-re-
lated quality of life by enhancing psychological
well-being and by improving physical function-
ing in persons compromised by poor health.

Adverse Effects
1. Most musculoskeletal injuries related to physical
activity are believed to be preventable by gradu-
ally working up to a desired level of activity and
by avoiding excessive amounts of activity.
2. Serious cardiovascular events can occur with
physical exertion, but the net effect of regular
physical activity is a lower risk of mortality from
  cardiovascular disease.

Chapter 5: Patterns and Trends
in Physical Activity
Adults

1. Approximately 15 percent of U.S. adults engage
regularly (3 times a week for at least 20 minutes)
in vigorous physical activity during leisure time.
2. Approximately 22 percent of adults engage regu-
larly (5 times a week for at least 30 minutes) in
sustained physical activity of any intensity dur-
ing leisure time.

3. About 25 percent of adults report no physical
activity at all in their leisure time.
4. Physical inactivity is more prevalent amongwomen
than men, among blacks and Hispanics than whites,
among older than younger adults, and among the
less affluent than the more affluent.

5. The most popular leisure-time physical activities
among adults are walking and gardening or yard
work.

Adolescents and Young Adults
1. Only about one-half of U.S. young people (ages
12-21 years) regularly participate in vigorous
physical activity. One-fourth report no vigorous
physical activity.

2. Approximately one-fourth of young people walk
or bicycle (i.e., engage in light to moderate activ-
ity) nearly every day.

3. About 14 percent of young people report no
recent vigorous or light-to-moderate physical
activity. This indicator of inactivity is higher
among females than males and among black
females than white females.

4. Males are more likely than females to participate
in vigorous physical activity, strengthening ac-
tivities, and walking or bicycling.
5. Participation in all types of physical activity de-
clines strikingly as age or grade in school increases.
6. Among high school students, enrollment in physi-
cal education remained unchanged during the
first half of the 1990s. However, daily attendance
in physical education declined from approxi-
mately 42 percent to 25 percent.
7. The percentage of high school students who were
enrolled in physical education and who reported
being physically active for at least 20 minutes in
physical education classes declined from approxi-
mately 81 percent to 70 percent during the first
  half of this decade.

8. Only 19 percent of all high school students report
being physically active for 20 minutes or more in
daily physical education classes.

Chapter 6: Understanding and
Promoting Physical Activity
1. Consistent influences on physical activity pat-
terns among adults and young people include
confidence in one's ability to engage in regular
physical activity (e.g., self-efficacy), enjoyment
of physical activity, support from others, positive
beliefs concerning the benefits of physical activ-
ity, and lack of perceived barriers to being physi-
cally active.
2. For adults, some interventions have been success-
ful in increasing physical activity in communities,
worksites, and health care settings, and at home.
3. Interventions targeting physical education in
elementary school can substantially increasethe
amount of time students spend being physically
active in physical education class.

8


               CHAPTER 2
HISTORICAL BACKGROUND, TERMINOLOGY,
  EVOLUTION OF RECOMMENDATIONS,
           AND MEASUREMENT

Contents

Introduction . . . . ..___..______....................._________................. 11

Western Historical Perspective  ..................................................  12
Early Promotion of Physical Activity for Health .................................. 12
Associating Physical Inactivity with Disease   ....................................  15
Health, Physical Education, and Fitness  ........................................  16
Exercise Physiology Research and Health .......................................  18

Terminology of Physical Activity, Physical Fitness, and Health . . . . . . . . . . . . . . . . . . . . . 20

Evolution of Physical Activity Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Summary of Recent Physical Activity Recommendations . , . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Measurement of Physical Activity, Fitness, and Intensity  ............................. 29
Measuring Physical Activity  ................................................. 29
  Measures Based on Self-Report  ............................................ 29
  Measures Based on Direct Monitoring  ....................................... 31
  Measuring Intensity of Physical Activity  ..................................... 32
  Measuring Physical Fitness  ............................................... 33
     Endurance  .......................................................... 33
     Muscular Fitness  ..................................................... 34
    Body Composition  ................................................... 35
  Validity of Measurements  ................................................ 35

Chaptersummary . .._._.................................................... . . 37


Contents, continued

Conclusions . . . .._.._.____.................................................. 37

References . . . . . . . . . . . . . . . . .._..._....._._...............___._............... 37

Appendix A: Healthy People 2000 Objectives _ . . . . . . . . . . . . . . . _ _ _ _ . . . . . . . . . . .-. 47

Appendix B: NIH Consensus Conference Statement  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . _ . . 50


               CHAPTER 2
HISTORICAL BACKGROUND, TERMINOLOGY,
  EVOLUTION OF RECOMMENDATIONS,

AND MEASUREMENT

Introduction

The exercise boom is notjust afad; it is a return
to `nutwrul' activity-the kind for which our
bociics are engineered and whichfacilitates the
proper/unction of our biochemistry and physi-
ology. Viewed through the perspective ofevolu-
tiotmry time, sedentary existence, possible for
grcut numbers of people only during the lust
century, represents a transient, unnatural uber-
ration. (Eaton,Shostak, Konner 1988, p. 168)

T hischapter examines the historical development
of physical activity promotion as a means to
improve health among entire populat,ions. The chap-
tcr focuses on Western (i.e., Greco-Roman) history,
bccausc of the near-linear development of physical
activity promotion across those times and cultures
Icading to current American attitudes and guidelines
regarding physical activity. These guidelines are
discussed in detail in the last half of the chapter. To
Ilcsh out this narrow focus on Western traditions, as
well as to provide a background for the promotional
emphasis of the chapter, this chapter begins by
briefly outlining both anthropological and historical
evidence of the central, "natural" role of physical
activity in prehistoric cultures. Mention is also made
of the historical prominence of physical activity in
non-Greco-Roman cultures, including those of China,
India, Africa, and precolonial America.

Xrchaeologists working in conjunction withmedi-
Cal anthropologists have established that our ances-
tors up through the beginning of the Industrial
Revolution incorporated strenuous physical activity
as a normal part of their daily lives-and not only for
the daily, subsistence requirements of their "work"
.li\cs. Investigations of preindustrial societies still

intact today confirm that physical capability was not
just a grim necessity for success at gathering food and
providing shelter and safety (Eaton, Shostak, Konner
1988). Physical activity was enjoyed throughout every-
day prehistoric life, as an integral component of
religious, social, and cultural expression. Food sup-
plies for the most part were plentiful, allowing ample
time for both rest and recreational physical endeavors.
Eaton, Shostak, and Konner (1988) describe a
"Paleolithic rhythm" (p. 32) observed among con-
temporary hunters and gatherers that seems to
mirror the medical recommendations for physical
activity in this report. This natural cycle of regu-
larly intermittent activity was likely the norm for
most of human existence. Sustenance preoccupa-
tions typically were broken into l- or 2-day periods
of intense and strenuous exertion, followed by l- or
2-day periods of rest and celebration. During these
rest days, however, less intense but still strenuous
exertion accompanied 6- to 20-mile round-trip vis-
its to other villages to see relatives and friends and
to trade with other clans or communities. There or
at home, dancing and cultural play took place.
As the neolithic Agricultural Revolution allowed
more people to live in larger group settings and
cities, and as the specialization of occupations re-
duced the amount and intensity of work-related
physical activities, various healers and philosophers
began to stress that long life and health depended on
preventing illnesses through proper diet, nutrition,
and physical activity. Such broad prescriptions for
health, including exercise recommendations, long
predate the increasingly specific guidelines of classi-
cal Greek philosophy and medicine, which are the
predominant historical focus of this chapter.


Physical Activity and Health

In ancient China as early as 3000 to 1000 B.C.,
the classic Yellow Emperor's Book ojlnternal Medicine
(Huang Ti 1949) first described the principle that
human harmony with the world was the key to
prevention and that prevention was the key to long
life (Shampo and Kyle 1989). These principles grew
into concepts that became central to the 6th century
Chinese philosophy Taoism, where longevity through
simple living attained the status of a philosophy that
has guided Chinese culture through the present day.
tai chi chuan, an exercise system that teachesgraceful
movements, began as early as 200 B.C. with Hua T'o
and has recently been shown to decrease the incidence
of falls in elderly Americans (Huard and Wong 1968;
see Chapter 4).

In India, too, proper diet and physical activity
were known to be essential principles of daily
living. The Ajur Veda, a collection of health and
medical concepts verbally transmitted as early as
3000 B.C., developed into Yoga, a philosophy that
included a comprehensively elaborated series of
stretching and flexibility postures. The principles
were first codified in 600B.C. in the Upanishads and
later in the Yoga Sutras by Patanjali sometime be-
tween 200 B.C. and 200 A.D. Yoga philosophies
also asserted that physical suppleness, proper breath-
ing, and diet were essential to control the mind and
emotions and were prerequisites for religious ex-
perience. In both India and China during this
period, the linking of exercise and health may
have led to the development of a medical subspe-
cialty that today would find its equivalent in sports
medicine (Snook 1984).

Though less directly concerned with physical
health than with social and religious attainment,
physical activity played a key role in other ancient
non-Greco-Roman cultures. In Africa, systems of
flexibility, agility, and endurance training not only
represented the essence of martial arts capability
but also served as an integral component bf reli-
gious ritual and daily life. The Sambuiu and the
Masai of Kenya still feature running as a virtue of
the greatest prowess, linked to manhood and social
stature.

Similarly, in American Indian cultures, running
was a prominent feature of all major aspects of life
(Nabokov 1981). Long before the Europeans in-
vaded, Indians ran to communicate, to fight, and to

hunt. Running was also a means for diverse Ameri-
can Indian cultures to enact their myths and thereby
construct a tangible link between themselves and
both the physical and metaphysical worlds. Among
the Indian peoples Nabokov cites are the Mesquakie
of Iowa, the Chemeheuvi of California, the Inca of
Peru, the Zuni and other Pueblo peoples of the
American Southwest, and the Iroquois of the Ameri-
can East, who also developed the precursor of mod-
ern-day lacrosse. Even today, the Tarahumarahe of
northern Mexico play a version of kickball that
involves entire villages for days at a.time (Nabokov
1981; Eaton, Shostak, Konner 1988).

Western Historical Perspective

Besides affecting the practice of preventive hygiene
(as is discussed throughout this section), the ancient
Greek ideals of exercise and health have influenced
the attitudes of modern western culture toward
physical activity. The Greeks viewed great athletic
achievement as representing both spiritual and
physical strength rivaling that of the gods (Jaeger
1965). In the classical-era Olympic Games, the Greeks
viewed the winners as men who had the character
and physical prowess to accomplish feats beyond the
capability of most mortals. Although participants in
the modern Olympic Games no longer compete with
the gods, today's athletes inspire others to be physi-
cally active and to realize their potential-an inspi-
ration as important for modern peoples as it was for
the ancient Greeks.

Early Promotion of
Physical Activity for Health
Throughout much of recorded western history, phi-
losophers, scientists, physicians, and educators have
promoted the idea that being physically active con-
tributes to better health, improved physical func-
tioning, and increased longevity. Although some of
these claims were based on personal opinions or
clinical judgment, others were the result of system-
atic observation.

Among the ancient Greeks, the recognition that
proper amounts of physical activity are necessary for
healthy living dates back to at least the 5th century
B.C. (Berryman 1992). The lessons found in the

12


Historical Background, Terminology, Evolution of Recommendations, and Measurement

..lalVs of health" taught during the ancient period
sound familiar lo us today: to breathe fresh air, eat
prc>pcr foods, drink the right beverages, take plenty
L,f cscrcise, get the proper amount of sleep, and
inciudc our emotions when analyzing our overall
\vcll-being.

\vcstern historians agree that the close connec-
tlon hctween exercise and medicine dates back to
lhrcc Greek physicians-Herodicus (ca. 480 B.C.),
Hippocrates (ca. 460-ca. 377 B.C.), and Galen
(/I.D. 129-ca. 199). The first to study therapeutic
$~ll~n:~stics--or gymnastic medicine, as it was often
caitcd-was the Greek physician and former exer-
cisc instructor, Herodicus. His dual expertise united
rhc gymnastic with the medical art, thereby prepar-
ing the way for subsequent Greek study of the health
hcncfits of physical activity.
Although Hippocrates is generally known as the
father of preventive medicine, most historians credit
I Icroclicus as the influence behind Hippocrates' in-
lcrcst in the hygienic usesofexerciseanddiet (Cyriax
1~ 1-t; Prccope 1952; Licht 1984; Olivova 1985).
K~~gimcn, the longer of Hippocrates' two works deal-
111g with hygiene, was probably written sometime
mend 400 B.C. In Book 1, he writes:

Eafing alone will not keep a man well; he must
also take exercise. Forfoodand exercise, white
posscssingoppositequalities,yet work together
IO produce health. For it is the nature ofexer-
cisc to USC up material, but offood and drink to
mokc good dejiciencies. And it is necessary, as
il clppcars, to discern the power of various
cxcrcises, both natural exercises andartificial,
to know which of them tends to increaseflesh
cold which to lessen it; and not only this, but
&o to proportion exercise to bulk offood, to
the constitution of the patient, to the age ofthe
i~ldividual, to the season of the year, to the
chclngcs in the winds, to the situation of the
region in which the patient resides, and to the
CoMilu~ion of the year. (1953 reprint, p. 229)
Hippocrates was a major influence on the career
of Claudius Galenus, or Galen, the Greek physician
lvllo wrote numerous works of great importance to
lncdical history during the second century. Of these
.\rorks, his book entitled On Hygiene contains the
lllost information on the healthfulness of exercise.

Whether by sailing, riding on horseback, or driving,
or via cradles, swings, and arms, everyone, even
infants, Galen said, needed exercise (Green 1951
trans., p. 25). He further stated:

The uses of exercise, I think, are twofold, one
for the evacuation ofthe excrements, the other
for the production ofgood condition ofthefit-m
parts oJthe body. For since vigorous motion is
exercise, it must needs be that only these three
things result from it in the exercising body-
hardness of the organs from mutual attrition,
increase of the intrinsic warmth, and acceler-
ated movement of respiration. These are fol-
lowed by all the other individual benefits which
accrue to the bodyfrom exercise;from hardness
of the organs, both insensitivity and strength
forfunction; from warmth, both strongatlrac-
tion for things to be eliminated, readier me-
tabolism, and better nutrition and diffusion of
all substances, whereby it results that solidsare
softened, liquids diluted, and ducts dilated.
And from the vigorous movement of respira-
tion the ducts must be purged and the excre-
ments evacuated. (p. 54)

The classical notion that one could improve
one's health through one's own actions-for ex-
ample, through eating right and getting enough sleep
and exercise -proved to be a powerful influence on
medical theory as it developed over the centuries.
Classical medicine had made it clear to physicians
and the lay public alike that responsibility for disease
and health was not the province of the gods. Each
person, either independently or in counsel with his
or her physician, had a moral duty to attain and
preserve health. When the Middle Ages gave way to
the Renaissance, with its individualistic perspective
and its recovery of classical humanistic influences,
this notion of personal responsibility acquired even
greater emphasis. Early vestiges of a "self-help"
movement arose in western Europe in the 16th
century. As that century progressed, "laws of bodily
health were expressed as value prescriptions" (Burns
1976, p. 208).

More specifically, "orthodox Greek hygiene,"
as Smith (1985, p. 257) called it, flourished as part
of the revival of Galenic medicine as early as the
13th century. The leading medical schools of the


Physical Activity and Health

world--Italy's Salerno, Padua, and Bologna-taught
hygiene to their students as part of general instruc-
tion in the theory and practice of medicine The
works of Hippocrates and Galen dominated a sys-
tem whereby "the ultimate goal was to be able to
practise medicine in the manner of the ancient
physicians" (Bylebyl 1979, p. 341).
Hippocrates' Regimen also became important
during the Renaissance in a literature that Gruman
(1961) identified as "prolongevity hygiene" and de-
fined as "the attempt to attain a markedly increased
longevity by means of reforms in one's way of life"
(p. 221). Central to this literature was the belief that
persons who decided to live a temperate life, espe-
cially by reforming habits of diet and exercise, could
significantly extend their longevity. Beginning with
the writings of Luigi Cornaro in 1558, the classic
Greek preventive hygiene tradition achieved increas-
ing attention from those wishing to live longer and
healthier lives.

Christobal Mendez, who received his medical
training at the University of Salamanca, was the
author of the first printed book devoted to exercise,
Book of Bodily Exercise (1553). His novel and com-
prehensive ideas preceded developments in exercise
physiology and sports medicine often thought to be
unique to the early 20th century. The book consists
of four treatises that cover such topics as the effects
of exercise on the body and on the mind. Mendez
believed, as the humoral theorists did, that the phy-
sician had to clear away excess moisture in the body.
Then, after explaining the ill effects of vomiting,
bloodletting, purging, sweating, and urination, he
noted that "exercise was invented and used to clean
the body when it was too full of harmful things. It
cleans without any of the above-mentioned inconve-
nience and is accompanied by pleasure and joy (as
we will say). If we use exercise under the conditions
which we will describe, it deserves lofty' praise as a
blessed medicine that must be kept in high esteem"
(1960 reprint, p. 22).

In 1569, Hieronymus Mercurialis' The Art of
Gymnastics Among the Ancients was published in
Venice. Mercurialis quoted Galen extensivly and
provided a descriptive compilation of ancient mate-
rial from nearly 200 works by Greek and Roman
authors. In general, Mercurialis established the fol-
lowing exercise principles: people who are ill should

not be given exercise that might aggravate existing
conditions; special exercises should be prescribed on
an individual basis for convalescent, weak, and older
patients; people who lead sedentary lives need ex-
ercise urgently; each exercise should preserve the
existing healthy state; exercise should not disturb
the harmony among the principal humors; exercise
should be suited to each part of the body; and all
healthy people should exercise regularly.
Although Galenism and the humoral theory of
medicine were displaced by new ideas, particularly
through the study of anatomy and physiology, the
Greek principles of hygiene and regimen continued
to flourish in 18th century Europe. For some 18th
century physicians, such nonintervention tactics were
practical alternatives to traditional medical therapies
that employed bloodletting and heavy dosing with
compounds of mercury and drugs-"heroic" medi-
cine (Warner 1986), in which the "cure" was often
worse than the disease.

George Cheyne's An Essay ofHealth and Long LiJe
was published in London in 1724. By 1745, it had
gone through 10 editions and various translations.
Cheyne recommended walking as the "most natural"
and "most useful" exercise but considered riding on
horseback as the "most manly" and "most healthy"
(1734 reprint, p. 94). He also advocated exercises in
the open air, such as tennis and dancing, and recom-
mended cold baths and the use of the "flesh brush"
to promote perspiration and improve circulation.
John Wesley's Primitive Physic, first published in
1747, was influenced to a large degree by George
Cheyne. In his preface, Wesley noted that "the power
of exercise, both to preserve and restore health, is
greater than can well be conceived; especially in
those who add temperance thereto" (1793 reprint,
p. iv). William Buchan's classic Domestic Medicine,
written in 1769, prescribed proper regimen for im-
proving individual and family health. The book
contained rules for the healthy and the sick and
stressed the importance ofexercise for good health in
both children and adults.

During the 19th century, both the classical Greek
tradition and the general hygiene movement were
finding their way into the United States through
American editions of western European medical
treatises or through books on hygiene written by
American physicians. The "self-help" era was also in

14


full bloom during antebellum America. Early ves-
tiges of a self-help movement had arisen in western
Europe in the 16th century. AS that century pro-
grcssed, .&laws of bodily health were expressed as
\aluc prescriptions " (Burns 1976, p. 208). Classical
Greek preventive hygiene was part of formal medical
training through the 18th century and continued on
in the American health reform literature for most of
the 19th century. During the latter period, an effort
~`as made to popularize the Greek laws of health, to
lrlilkc each person responsible for the maintenance
;lnd balance of his or her health. Individual reform
lvritcrs thus wrote about self-improvement, self-
regulation, the responsibility for personal health,
;~nd self-management (Reiser 1985). Ifpeople ate too
much, slept too long, or did not get enough exercise,
they could only blame themselves for illness. By the
3ilmt` token, they could also determine their own
good health (Cassedy 1977; Numbers 1977;
Vcrhrugge 1981; Morantz 1984).
A.F.M. Willich's Lectures on Diet and Regimen
( 1801) emphasized the necessity of exercise within
lhc hounds of moderation. He included information
OII specific exercises, the time for exercise, and the
duration of exercise. The essential advantages of
cscrcisc included increased bodily strength, improved
circulation of the blood and all other bodily fluids,
Cl in necessary secretions and excretions, help in
clearing and refining the blood, and removal of
obstructions.

John Gunn's classic Domestic Medicine, Or Poor
.HuII's Friend, was first published in 1830. His section
c*ntitlcd "Exercise" recommended temperance, exer-
cisc, and rest and valued nature's way over tradi-
lional medical treatment. He also recommended
cscrcise for women and claimed that all of the
"diseases of delicate women" like "hysterics and
hypochondria, arise from want of due exercise in the
open, mild, and pure air" (1986 reprint; p. 109).
Fill:$`, in an interesting statement fdr the 1830s if
IlOt the 199Os, Gunn recommended a training sys-
`cln for all: "The advantages of the training systems
:\rc not confined to pedestrians or walkers-or to
Pugilists or boxers alone; or to horses which are
trained for the chase and the race track; they extend
10 man in all conditions; and were training intro-
duced into the United States, and made use of by
physicians in many cases instead of medical drugs,

Historical Background, Terminology, Evolution of Recommendations, and Measurement

the beneficial consequences in the cure of many
diseases would be very great iFed" (p. 113).

Associating Physical Inactivity with Disease
Throughout history, numerous health professionals
have observed that sedentary people appear to suffer
from more maladies than active people. An early
example is found in the writings of English physician
Thomas Cogan, author of TheHavenofHealth (1584);
he recommended his book to students who, because
of their sedentary ways, were Gelieved to be most
susceptible to sickness.

In his 1713 book Diseases of Workers, Bernar-
dino Ramazzini, an Italian physician considered the
father of occupational medicine, offered his views on
the association between chronic inactivity and poor
health. In the chapter entitled "Sedentary Workers
and Their Diseases," Ramazzini noted that "those
who sit at their work and are therefore called `chair-
workers,' such as cobblers and tailors, suffer from
their own particular diseases." He concluded that
"these workers . . _ suffer from general ill-health and
an excessive accumulation of unwholesome humors
caused by their sedentary life," and he urged them to
at least exercise on holidays "so to some extent
counteract the harm done by many days of sedentary
life" (1964 trans., pp. 281-285).
Shadrach Ricketson, a New York physician, wrote
the first American text on hygiene and preventive
medicine (Rogers 1965). In his 1806 book Means of
Preserving Health and Preventing Diseases, Ricketson
explained that "a certain proportion of exercise is not
much less essential to a healthy or vigorous constitu-
tion, than drink, food, and sleep; for we see that
people, whose inclination, situation, or employ-
ment does not admit of exercise, soon become pale;
feeble, and disordered." He also noted that "exercise
promotes the circulation of the blood, assists diges-
tion, and encourages perspiiation" (pp. 152-153).
Since the 186Os, physicians and others had
been attempting to assess the longevity of runners
and rowers. From the late 1920s (Dublin 1932;
Montoye 1992) to the landmark paper by Morris
and colleagues (1953), observations that prema-
ture mortality is lower among more active persons
than sedentary persons began to emerge and were
later replicated in a variety of settings (Rook 1954;

15


Physical Activity and Health

Brown et al. 1957; Pomeroy and White 1958; Zukel
et al. 1959). The hypothesis that a sedentary lifestyle
leads to increased mortality from coronary heart
disease, as well as the later hypothesis that inactiv-
ity leads to the development of some other chronic
diseases, has been the subject of numerous studies
that provide the major source of data supporting
the health benefits of exercise (see Chapter 4).

Health, Physical Education, and Fitness
The hygiene movement found further expression in
19th century America through a new literature de-
voted to "physical education." In the early part of the
century, many physicians began using the term in
journal articles, speeches, and book titles to describe
the task of teaching children the ancient Greek "laws
of health." As Willich explained in his Lectures on Diet
and Regimen (1801), "by physical education is meant
the bodily treatment of children; the term physical
being applied in opposition to mord (p. 60). In his
section entitled "On the Physical Education of Chil-
dren," he continued to discuss stomach ailments,
bathing, fresh air, exercise, dress, and diseases of the
skin, among other topics. Physical education, then,
implied not merely exercising the body but also
becoming educated about one's body.
These authors were joined by a number of early
19th century educators. For example, an article
entitled "Progress of Physical Education" (1826),
which appeared in the first issue of American journal
of Education, declared that "the time we hope is
near, when there will be no literary institution
unprovided with the proper means to healthful
exercise and innocent recreation, and when literary
men shall cease to be distinguished by a pallid
countenance and a wasted body" (pp. 19-20). Both
William Russell, who was the journal's editor, and
Boston educator William Fowler believed that girls
as well as boys should have ample outdoor exercise.
Knowledge about one's body also was deemed cru-
cial to a well-educated and healthy individual by
several physicians who, as Whorton has suggested,
"dedicated their careers to birthing the modern
physical education movement" (p. 282).
  Charles Caldwell held a prominent position in
Lexington, Kentucky's, Transylvania University
Medical Department. Although he wrote on a variety
of medical topics, his Thoughts on Physical Education

in 1834 gained him national recognition. Caldwell
defined physical education as "that scheme of train-
ing, which contributes most effectually to the devel-
opment, health, and perfection of living matter. As
applied to man, it is that scheme which raises his
whole system to its summit of perfection. . . . Physical
education, then, in its philosophy and practice, is of
great compass. If complete, it would be tantamount
to an entire system of Hygeiene. It would embrace
every thing, that, by bearing in any way on the
human body, might injure or benefit it in its health,
vigor, and fitness for action" (pp. 28-29).
During the first half of the 19th century, systems
of gymnastic and calisthenic exercise that had been
developed abroad were brought to the United States.
The most influential were exercises advanced by Per
Henrik Ling in Sweden in the early 1800s and the
"German system" of gymnastic and apparatus exer-
cises that was based on the work of Johan Christoph
GutsMuths and Friedrich LudwigJahn. Also, Ameri-
cans like Catharine Beecher (1856) and Dioclesian
Lewis (1883) devised their own extensive systems of
calisthenic exercises intended to benefit both women
and men. By the 187Os, American physicians and
educators frequently discussed exercise and health.
For example, physical training in relation to health
was a regular topic in the Boston Medical and Surgical
Journal from the 1880s to the early 1900s.
Testing of physical fitness in physical education
began with the extensive anthropometric documen-
tation by Edward Hitchcock in 1861 at Amherst
College. By the 188Os, Dudley Sargent at Harvard
University was also recording the bodily measure-
ments of college students and promoting strength
testing (Leonard and Affleck 1947). During the early
19OOs, the focus on measuring body parts shifted to
tests of vital working capacity. These tests included
measures of blood pressure (McCurdy 1901;
McKenzie 1913), pulse rate (Foster 1914), and fa-
tigue (Storey 1903). As early as 1905, C. Ward
Crampton, former director of physical training and
hygiene in New York City, published the article "A
Test of Condition" in Medical News. Attempts to
assess physical fitness had constituted a significant
aspect of the work of turn-of-the-century physical
educators, many of whom were physicians.
  Allegations that American conscripts during
World War I were inadequately fit to serve their

16


countq helped shift the emphasis of physical educa-
tion from health-related exercise to performance out-
c`omcs. Public concern stimulated legislation to make
ph\.r;ical education a required subject in schools. But
the financial austerities of the Great Depression had a
neg;ltive effect on education in general, including
physical education (Rogers 1934). At the same time,
the combination of increased leisure time for many
;\mericans and a growing national interest in college
;md high school sports shifted the emphasis on physi-
(al education away from the earlier aim of enhancing
performance and health to a new focus on sports-
related skills and the worthy use of leisure time.
physical efficiency was a term widely used in
the literature of the 1930s. Another term, physical
condition, also found its way into research reports.
111 1936, Arthur Steinhaus published one of the
carlicst articles on "physical fitness" in thejournal
(I\- ffctrld~, Pllysical Education, and Recreation; in
1038, C. H. McCloy's article "Physical Fitness and
<;itizenship" appeared in the same journal.
  As the United States entered World War II, the
Icdcral government showed increasing interest in
physical education, especially toward physical fit-
ucss testing and preparedness. In October 1940,
President Franklin Roosevelt named John Kelly, a
lormcr Olympic rower, to the new position of
national director of physical training. The follow-
i ng year, Fiorella La Guardia, the Mayor of New
York City and the director of civilian defense for the
I'cdcral Security Agency, appointed Kelly as assis-
tant in charge of physical fitness; tennis star Alice
Marble was also chosen to promote physical fitness
among girls and women (Park 1989; Berryman
1995).

In 1943, Arthur Steinhaus chaired a committee
ilppointed by the Board of Directors of the American
Medical Association to review the nature and role of
exercise in physical fitness (Steinhaus et al. 1943),
and C. Ward Crampton chaired a committee on
Physical fitness under the direction'of the Federal
Security Agency. Crampton and his 73-member
advisory council were charged with developingphysi-
~a1 fitness in the civilian population (Crampton 1941;
Park 1989).

In 1941, Morris Fishbein, editor of theJournal of
the American Medical Association, stated that "from
the point of view on physical fitness we are a far

better nation now than we were in 1917," but he
cautioned Americans not to believe "we have at-
tained an optimum in physical fitness" (p. 54). He
realized the magnitude of the fitness problem when
he noted that the poor results of physical examina-
tions reported by the Selective Service Boards were "a
challenge to the medical profession, to the social
scientists, the physical educators, the public health
officials, and all those concerned in the United States
with the physical improvement of our population"
(p. 55). The goals most frequently cited for physical
education between 1941 and 1945 were resistance to
disease, muscular strength and endurance, cardio-
respiratory endurance, muscular growth, flexibility,
speed, agility, balance, and accuracy (Larson and
Yocom 1951).

After World War II concluded, a continuing
interest in physical fitness convinced other key mem-
bers of the medical profession and the American
Medical Association to continue studying exercise.
Much of this interest can be attributed to the pioneer-
ing work of Thomas K. Cureton, Jr., and his Physical
Fitness Research Laboratory at the University of Illinois
(Shea 1993). Cardiologists, health education special-
ists, and physicians in preventive medicine were be-
coming aware of the contributions of exercise to the
overall health and efficiency of the heart and circula-
tory system. In 1946, the American Medical
Association's Bureau of Health Education designed
and organized the Health and Fitness Program to
provide "assistance to local organizations throughout
the nation in the development of satisfactory health
education programs" (Fishbein 1947, p. 1009). The
program became an important link among physical
educators, physicians, and physiologists.
The event that attracted the most public attention
to physical fitness, including that of President Dwight
D. Eisenhower, was the publication of the article
"Muscular Fitness and Health" in the December 1953
issue of the Journal of Health, Physical Education,
and Recreation. The authors, Hans Kraus and Ruth
Hirschland of the Institute of Physical Medicine
and Rehabilitation at the New York University
Bellevue Medical Center, stated that 56.6 per-
cent of the American schoolchildren tested "failed
to meet even a minimum standard required for
health" (p. 17). When this rate was compared with
the 8.3 percent failure rate for European children, a

Historical Background, Terminology, Evolution of Recommendations, and Measurement

17


Physical Activity and Health

call for reform went out. Kraus and Hirschland
labeled the lack of sufficient exercise "a serious
deficiency comparable with vitamin deficiency" and
declared "an urgent need" for its remedy (pp. 17-19).
John Kelly, the former national director of physical
fitness during World War II, notified Pennsylvania
Senator James Duff of these startling test results.
Duff, in turn, brought the research to the attention of
President Eisenhower, who invited several athletes
and exercise experts to a meeting in 1955 to examine
this issue in more depth. A President's Conference
on Fitness of American Youth, held in June 1956,
was attended by 150 leaders from government, physi-
cal education, medical, public health, sports, civic,
and recreational organizations. This meeting even-
tually led to the establishment of the President's
Council on Youth Fitness and the President's Citizens
Advisory Committee on the Fitness of American
Youth (Hackensmith 1966; Van Dalen and Bennett
1971).

When John Kennedy became president in 1961,
one of his first actions was to call a conference on
physical fitness and young people. Iri 1963, the
President's Council on Youth Fitness was renamed
the President's Council on Physical Fitness. In 1968,
the word "sports" was added to the name, making it
the President's Council on Physical Fitness and Sports
(PCPFS). The PCPFS was charged with promoting
physical activity, fitness, and sports for Americans of
all ages.

During the 1960% a number of educational and
public health organizations published articles and
statements on the importance of fitness for children
and youths. The American Association for Health,
Physical Education, and Recreation (AAHPER) ex-
panded its physical fitness testing program to in-
clude college-aged men and women. The association
developed new norms from data collected from more
than 11,000 boys and girls lo-17 years old. The
AAHPER also joined with the President's Cduncil on
Physical Fitness to conduct the AAHPER Youth
Fitness Test, which had motivational awards. In
1966, President Lyndon Johnson's newly created
Presidential Physical Fitness Award was incorpo-
rated into the program.

In the mid-1970s, the need to promote the health-
rather than exclusively the performance-benefits of
exercise and physical fitness began to reappear. In

1975, AAHPER stated it was time to differentiate
physical fitness related to health from performance
related to athletic ability (Blair, Falls, Pate 1983).
Accordingly, AAHPER commissioned the develop-
ment of the Health Related Physical Fitness Test. This
move in youth fitness paralleled the adoption of the
aerobic concept, which promoted endurance-type
exercise among the public (Cooper 1968).

Exercise Physiology Research and Health
The study of the physiology of exercise in a modern
                             r
sense began in Paris, France, when Antoine Lavoisier
in 1777 and Lavoisier and Pierre de Laplace in 1780
developed techniques to measure oxygen uptake and
carbon dioxide production at rest and during exer-
cise. During the 18OOs, European scientists used and
advanced these procedures to study the metabolic
responses to exercise (Scharling 1843; Smith 1857;
Katzenstein 1891; Speck 1889; Allen and Pepys
1809). The first major application of this research to
humans-Edward Smith's study of the effects of
"assignment to hard labor" by prisoners in London
in 1857-was to determine if hard manual labor
negatively affected the health and welfare of the
prisoners and whether it should be considered cruel
and unusual punishment.

William Byford published "On the Physiology of
Exercise" in the American Journal of Medical Sciences
in 1855, and Edward Mussey Hartwell, a leading
physical educator, wrote a two-part article, "On the
Physiology of Exercise, " for the Boston Medical and
SurgicalJournal in 1887. The first important book on
the subject, George Kolb's Beitrage zur Physiologic
Maximaler Muskelarbeit Besondersdes ModemenSports,
was published in 1887 (trans. Physiology of Sport,
1893) (cited in Langenfeld 1988 and Park 1992). The
followingyear,FernandLagrange'sPhysiology ofBodily
Exercise was published in France.
From the early 1900s to the early 192Os, several
works on exercise physiology began to appear. George
Fitz, who had established a physiology of exercise
laboratory during the early 189Os, published his
Principles of Physiology and Hygiene in 1908. R. Tait
McKenzie's Exercise in Education and Medicine (1909)
was followed by such works as Francis Benedict and
Edward Cathcart's Muscular Work, A Metabolic Study
with Special Reference to the Efficiency of the Human
Body as a Machine (1913). The next year, a professor

18


of physiology at the University of London, F.A.
Bainbridge, published a second edition of Physiology
(,I- .tlllscular Exercise (Park 1981).
In 1923, the year Archibald Hill was appointed
]oddrell Professor of Physiology at University Col-
lege, London, the physiology of exercise acquired
ot,c of its most respected researchers and staunchest
supporters, for Hill had won the Nobel Prize in
\Iedicine and Physiology the year before. Hill's 1925
prcsidcntial address on "The Physiological Basis of
*Athletic Records" to the British Association for the
;\dvancement of Science appeared in The Lancel
( I925a) and Scientgic Monthly (1925b), and in 1926
he published his landmark book Muscular Activity.
The following year, Hill published Living Machinery,
Lvhich was based largely on his lectures before audi-
I'IICCS at the Lowell Institute in Boston and the Baker
Laboratory of Chemistry in Ithaca, New York.
  Several leading physiologists besides Hill were
Intcrcstcd in the human body's response to exercise
ant1 cnvironmcntal stressors, especially activities
involving endurance, strength, altitude, heat, and
l~~lcl. Consequently, they studied soldiers, athletes,
;rvlators, and mountain climbers as the best models
lor acquiring data. In the United States, such re-
\c;lrch was centered in the Boston area, first at the
<:arncgic Nutrition Laboratory in the 1910s and
I;trcr at the Harvard Fatigue Laboratory, which was
c.>tablishcd under the leadership of Lawrence
I Icndcrson in 1927 (Chapman and Mitchell 1965;
I)ill lY67; Horvath and Horvath 1973). That year,
I Icnclcrson and colleagues first demonstrated that
~*ntlurancc exercise training improved the efficiency
()I the cardiovascular system by increasing stroke
~~~)lutnc and decreasing heart rate at rest. Two years
I;itcr, Schneider and Ring (1929) published the
rc5ults of a 12-week endurance training program on
c)lle person, demonstratinga 24-percent increase in
"crest load of oxygen" (maximal oxygen uptake).
over the next 15 years, a limited number of exercise
training studies were published that-evaluated the
--+csponsc of maximal oxygen uptake or endurance
Vrformancc capacity to exercise training. These
I~l~luded noteworthy reports by Gemmill and col-
Ic%ues (I931), Robinson and Harmon (1941), and
Knehr. Dill, and Neufeld (1942) on endurance
lraining responses by male college students. HOW-
cVer. none of those early studies compared the

Historical Background, Terminology, Evolution of Recommendations, and Measurement

effects of different types, intensities, durations, or
frequencies of exercise on performance capacity or
health-related outcomes.

Activities surrounding World War II greatly in-
fluenced the research in exercise physiology, and
several laboratories, including the Harvard Fatigue
Laboratory, began directing their efforts toward top-
ics of importance to the military. The other national
concern that created much interest among physiolo-
gists was the fear (discussed earlier in this chapter),
that American children were less fit than their Euro-
pean counterparts. Research was directed toward the
concept of fitness in growth and development, ways
to measure fitness, and the various components of
fitness (Berryman 1995). Major advances were also
made in the 1940s and 1950s in developing the
components of physical fitness (Cureton 1947) and
in determining the effects of endurance and strength
training on measures of performance and physi-
ologic function, especially adaptations of the cardio-
vascular and metabolic systems. Also investigated
were the effects ofexercise trainingon health-related
outcomes, such as cholesterol metabolism (Taylor,
Anderson, Keys 1957; Montoye et al. 1959).
Starting in the late 1950s and continuing through
the 197Os, a rapidly increasing number of published
studies evaluated or compared different components
of endurance-oriented exercise training regimens.
For example, Reindell, Roskamm, and Gerschler
(1962) in Germany, Christensen (1960) in Denmark,
and Yakovlev and colleagues (1961) in Russia
compared-and disagreed-about the relative ben-
efits of interval versus continuous exercise train-
ing in increasing cardiac stroke volume and
endurance capacity. Other investigators began to
evaluate the effects of different modes (Sloan and
Keen 1959) and durations (Sinasalo and Juurtola
1957) of endurance-type training on physiologic
and performance measures.

Karvonen and colleagues' (1957) landmark paper
that introduced using "percent maximal heart rate
reserve" to calculate or express exercise training in-
tensity was one of the first studies designed to com-
pare the effects of two different exercise intensities on
cardiorespiratory responses during exercise. Over the
next 20 years, numerous investigators documented
the effects of different exercise training regimens on a
variety of health-related outcomes among healthy

19


Physical Activity and Health

men and women and among persons under medical
care (Bouchard, Shephard, Stephens 1994). Many of
these studies evaluated the effects of endurance or
aerobic exercise training on cardiorespiratory capac-
ity and were initially summarized by Pollock (1973).
The American College of Sports Medicine (ACSM)
(1975, 1978) and the American Heart Association
(AHA) (1975) further refined the results of this re-
search (see the section on "Evolution of Physical
Activity Recommendations," later in this chapter).
Over the past two decades, experts from numer-
ous disciplines have determined that exercise training
substantially enhances physical performance and have
begun to establish the characteristics of the exercise
required to producespecific healthbenefits (Bouchard,
Shephard, Stephens 1994). Also, behavioral scientists
have begun to evaluate what determines physical
activity habits among different segments of the popu-
lation and are developing strategies to increase physi-
calactivityamongsedentary persons (Dishman 1988).
The results of much of this research are cited in the
other chapters of this report and were the focus of the
various conferences, reports, and guidelines summa-
rized later in this chapter.

  As the literature of exercise science has matured
and recommendations have evolved, certain widely
agreed-on terms have emerged. Because a number of
these occur throughout the rest of this chapter and
report, they are presented and briefly defined in the
following section.

Terminology of Physical Activity,
Physical Fitness, and Health

This section discusses four broad terms used frequently
in this report: physical activity, exercise (or exercise
training), physical fitness, and health. Also included is
a glossary (Table 2-l) of more specific terms and
concepts crucial to understanding the material pre-
sented in later parts of this chapter and report.

Physical activity. Physical activity is defined as
bodily movement produced by the contraction of
skeletal muscle that increases energy expenditure
above the basal level. Physical activity can be cat-
egorized in various ways, including type, intensity,
and purpose.

Because muscle contraction has both mechani-
cal and metabolic properties, it can be classified by

either property. This situation has caused some
confusion. Typically, mechanical classification
stresses whether the muscle contraction produces
movement of the limb: isometric (same length) or
static exercise if there is no movement of the limb, or
isotonic (same tension) or dynamic exercise if there
is movement of the limb. Metabolic classification
involves the availability of oxygen for the contrac-
tion process and includes aerobic (oxygen available)
or anaerobic (oxygen unavailable) processes.
Whether an activity is aerobic or anaerobic depends
primarily on its intensity. Most'activities involve
both static and dynamic contractions and aerobic
and anaerobic metabolism. Thus, activities tend to
be classified according to their dominant features.
The physical activity of a person or group is
frequently categorized by the context in which it
occurs. Common categories include occupational,
household, leisure time, or transportation. Leisure-
time activity can be further subdivided into catego-
ries such as competitive sports, recreational activities
(e.g., hiking, cycling), and exercise training.
Exercise (or exercise training). Exercise and
physical activity have been used synonymously in
the past, but more recently, exercise has been used to
denote a subcategory of physical activity: "physical
activity that is planned, structured, repetitive, and
purposive in the sense that improvement or mainte-
nance of one or more components of physical fitness
is the objective" (Caspersen, Powell, Christensen
1985). Exercise training also has denoted physical
activity performed for the sole purpose of enhancing
physical fitness.

Physical fitness. Physical fitness has been de-
fined in many ways (Park 1989). A generally ac-