Physical
Activity
and
Health
A Report of the Surgeon General
Executive Summary
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
The President’s
Council on
Physical Fitness
and Sports
Message from Donna E. Shalala
Secretary of Health 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 breakthrough
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 world’s
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’ 100-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; originally 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 disabilities.
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 promotion
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
activity, 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 Assistant Secretary
Centers for Disease Control for Health
and Prevention
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 implications
of this good news are 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. I strongly encourage all Americans to join
us in this effort.
Audrey F. Manley, M.D., M.P.H.
Surgeon General (Acting)
Contents
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Development of the Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Major Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Chapter Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Chapter 2: Historical Background and Evolution of Physical Activity Recommendations . . . 12
Chapter 3: Physiologic Responses and Long-Term Adaptations to Exercise . . . . . . . . . . . . 13
Chapter 4: The Effects of Physical Activity on Health and Disease . . . . . . . . . . . . . . . . . . . 13
Chapter 5: Patterns and Trends in Physical Activity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Chapter 6: Understanding and Promoting Physical Activity . . . . . . . . . . . . . . . . . . . . . . . . 14
CHAPTER 1
INTRODUCTION, SUMMARY,
AND CHAPTER CONCLUSIONS
CHAPTER 1
INTRODUCTION, SUMMARY,
AND CHAPTER CONCLUSIONS
Introduction
This is the first Surgeon General’s report to address
physical activity and health. The main
message of this report is that Americans can substantially
improve their health and quality of life by
including moderate amounts of physical activity in
their daily lives. Health benefits from physical activity
are thus achievable for most Americans, including
those who may dislike vigorous exercise and
those who may have been previously discouraged by
the difficulty of adhering to a program of vigorous
exercise. For those who are already achieving regular
moderate amounts of activity, additional benefits
can be gained by further increases in activity level.
This report grew out of an emerging consensus
among epidemiologists, experts in exercise science,
and health professionals that physical activity need
not be of vigorous intensity for it to improve health.
Moreover, health benefits appear to be proportional
to amount of activity; thus, every increase in activity
adds some benefit. Emphasizing the amount rather
than the intensity of physical activity offers more
options for people to select from in incorporating
physical activity into their daily lives. Thus, a moderate
amount of activity can be obtained in a 30-
minute brisk walk, 30 minutes of lawn mowing or
raking leaves, a 15-minute run, or 45 minutes of
playing volleyball, and these activities can be varied
from day to day. It is hoped that this different
emphasis on moderate amounts of activity, and the
flexibility to vary activities according to personal
preference 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,
exercise physiology, medicine, and the behavioral
sciences. The report highlights what is known about
physical activity and health, as well as what is being
learned about promoting physical 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 Prevention
(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 representatives
from the Office of the Surgeon General, the
Office of Public Health and Science (Office of the
Secretary), the Office of Disease Prevention (National
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 Institute
of Diabetes and Digestive and Kidney Diseases;
and the National Institute of Arthritis and Musculoskeletal
and Skin Diseases. CDC’s nonfederal partners—
including the American Alliance for Health,
Physical Education, Recreation, and Dance; the
American College of Sports Medicine; and the American
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 therefore
does not include the considerable body of evidence
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 (activity
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 beyond
the scope of this report. In addition, a review of the
special concerns regarding physical activity for pregnant
women and for people with disabilities is not
undertaken here, although these important topics deserve
more research and attention.
Finally, physical activity is only one of many everyday
behaviors that affect health. In particular, nutritional
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 Nutrition
and Health was published in 1988.
Chapters 2 through 6 of this report address distinct
areas of the current understanding of physical
activity and health. Chapter 2 offers a historical perspective:
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 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.
3. 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.
4. Physical activity reduces the risk of premature
mortality in general, and of coronary heart disease,
hypertension, colon cancer, and diabetes
mellitus in particular. Physical activity also improves
mental health and is important for the
health of muscles, bones, and joints.
5. More than 60 percent of American adults are not
regularly physically active. In fact, 25 percent of
all adults are not active at all.
6. Nearly half of American youths 12–21 years of age
are not vigorously active on a regular basis. Moreover,
physical activity declines dramatically during
adolescence.
7. 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 promoting physical
activity is at an early stage, but some interventions
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 cardiorespiratory
fitness that the American College of Sports
Medicine (ACSM), the American Heart Association
(AHA), and other national organizations began issuing
physical activity recommendations to the public.
These recommendations generally focused on cardiorespiratory
endurance and specified sustained
periods of vigorous physical activity involving large
10 Introduction, Summary, and Chapter Conclusions
muscle groups and lasting at least 20 minutes on 3 or
more days per week. As understanding of the benefits
of less vigorous activity grew, 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 People 2000 goals for the
nation’s health have recognized the importance of
physical activity and have included physical activity
goals. The 1995 Dietary Guidelines for Americans, the
basis of the federal government’s nutrition-related
programs, included physical activity guidance to
maintain 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 growing
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 reduced
risk of premature mortality and reduced risks
of coronary heart disease, hypertension, colon cancer,
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 problems
that have been associated with physical activity
are musculoskeletal injuries, which can occur with
excessive amounts of activity or with suddenly beginning
an activity for which the body is not conditioned.
Much more serious associated health
problems (i.e., myocardial infarction, sudden death)
are also much rarer, occurring primarily among
sedentary people with advanced atherosclerotic disease
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 somewhat
increased during physical exertion, but their
overall risk of these outcomes is lower than that
among people who are sedentary.
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 occurs
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 demonstrated,
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 recommendations
from the CDC and ACSM, as well as from the
NIH Consensus Development Conference on Physical
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 vigorous
exercise programs at one time or another, most
do not sustain their participation. Clearly, the processes
of developing and maintaining healthier habits
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. Determining
the most effective and cost-effective intervention
11
Physical Activity and Health approaches is a challenge for the future. Fortunately,
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 particularly
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 impact.
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 technological
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 report
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 information
about these important groups will be necessary
to develop a truly comprehensive national initiative
for better health through physical activity. Challenges
for the future include identifying key determinants
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 cardiorespiratory
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 performed
regularly. The most recent recommendations
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 embarking
on a physical activity program to start
with short durations of moderate-intensity activity
and gradually increase the duration or intensity
until the goal is reached.
5. Experts advise consulting with a physician before
beginning a new physical activity program for
people with chronic diseases, such as cardiovascular
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.
6. Recent recommendations from experts also suggest
that cardiorespiratory endurance activity
should be supplemented with strength-developing
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.
12
Introduction, Summary, and Chapter Conclusions
Chapter 3: Physiologic Responses and Long-
Term Adaptations to Exercise
1. Physical activity has numerous beneficial physiologic
effects. Most widely appreciated are its
effects on the cardiovascular and musculoskeletal
systems, but benefits on the functioning of
metabolic, endocrine, and immune systems are
also considerable.
2. 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.
3. 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
1. Higher levels of regular physical activity are associated
with lower mortality rates for both older
and younger adults.
2. Even those who are moderately active on a regular
basis have lower mortality rates than those
who are least active.
Cardiovascular Diseases
1. Regular physical activity or cardiorespiratory fitness
decreases the risk of cardiovascular disease
mortality in general and of coronary heart disease
mortality in particular. Existing data are not conclusive
regarding a relationship between physical
activity and stroke.
2. 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 exercise
reduces blood pressure in people with
hypertension.
Cancer
1. Regular physical activity is associated with a
decreased risk of colon cancer.
2. 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.
3. Despite numerous studies on the subject, existing
data are inconsistent regarding an association
between physical activity and breast or prostate
cancers.
Non–Insulin-Dependent Diabetes Mellitus
1.) Regular physical activity lowers the risk of developing
non–insulin-dependent diabetes mellitus.
Osteoarthritis
1. Regular physical activity is necessary for maintaining
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. Weight-bearing physical activity is essential for
normal skeletal development during childhood
and adolescence and for achieving and maintaining
peak bone mass in young adults.
2. It is unclear whether resistance- or endurancetype
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 training
and other forms of exercise in older adults
preserve the ability to maintain independent living
status and reduce the risk of falling.
Obesity
1. Low levels of activity, resulting in fewer kilocalories
used than consumed, contribute to the high
prevalence of obesity in the United States.
2. Physical activity may favorably affect body fat
distribution.
13
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 Quality of Life
1. Physical activity appears to improve health-related
quality of life by enhancing psychological
well-being and by improving physical functioning
in persons compromised by poor health.
Adverse Effects
1. Most musculoskeletal injuries related to physical
activity are believed to be preventable by gradually
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 regularly
(5 times a week for at least 30 minutes) in
sustained physical activity of any intensity during
leisure time.
3. About 25 percent of adults report no physical
activity at all in their leisure time.
4. Physical inactivity is more prevalent among women
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 activity)
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 activities,
and walking or bicycling.
5. Participation in all types of physical activity declines
strikingly as age or grade in school increases.
6. Among high school students, enrollment in physical
education remained unchanged during the
first half of the 1990s. However, daily attendance
in physical education declined from approximately
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 approximately
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 patterns
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 activity,
and lack of perceived barriers to being physically
active.
2. For adults, some interventions have been successful
in increasing physical activity in communities,
worksites, and health care settings, and at home.
3. Interventions targeting physical education in
elementary school can substantially increase the
amount of time students spend being physically
active in physical education class.
14
Introduction, Summary, and Chapter Conclusions
Mail to: Superintendent of Documents, P.O. Box 371954, Pittsburgh, PA 15250–7954
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