Health Benefits of Exercise



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.

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 work sites, 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.

This report brings together, for the first time, what has been learned about physical activity and health from decades of research. The following is a summary of the findings from the Surgeon General's Report on Physical Activity and Health.

Historical Background & Evolution of
Physical Activity Recommendations

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

Physiologic Responses & Long-Term Adaptations to Exercise

  • 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.
  • 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.


The Effects of Physical Activity on Health and Disease

Overall Mortality

  • Higher levels of regular physical activity are associated with lower mortality rates for both older and younger adults.
    Even those who are moderately active on a regular basis have lower mortality rates than those who are least active.
    Cardiovascular Diseases
  • 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.
  • 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.
  • Regular physical activity prevents or delays the development of high blood pressure, and exercise reduces blood pressure in people with hypertension.

Cancer

Patterns and Trends in Physical Activity

Adults

  • 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.
  • 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.
  • About 25 percent of adults report no physical activity at all in their leisure time.
  • 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.
  • The most popular leisure-time physical activities among adults are walking and gardening or yard work.

Understanding and Promoting Physical Activity

  • 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.
  • For adults, some interventions have been successful in increasing physical activity in communities, work sites, and health care settings, and at home.
  • Interventions targeting physical education in elementary school can substantially increase the amount of time students spend being physically active in physical education class.