1993 C.H. McCloy Research Lecture: Physical Activity, Physical Fitness, and Health
Blair, Steven N., Research Quarterly for Exercise and Sport
Key words: cardiovascular disease, epidemiology, health, physical fitness
Interest in the healthful effects of physical activity dates back to ancient times, but scientific study of the issue did not receive emphasis until the end of the 19th century. Early studies focused on physiology, and, in fact, three exercise physiologists (August Krogh, A. V. Hill, and Otto Meyerhof) received Nobel Prizes in the early 1920s for their research (Montoye, 1992). In the 1989 McCloy Lecture, Professor Park (1990) provided an excellent review of early scientific studies of exercise. Montoye extended these observations by including more recent reports on the relation of physical inactivity to health and disease.
This report examines recent evidence on the relations between physical activity, physical fitness, and health and draws conclusions about the possible causal nature of these associations. It also evaluates the public health burden of sedentary lifestyles in the United States and provides suggestions and recommendations for increasing participation in physical activity in the population.
on Activity, Fitness, and Health
Information about the relation of physical activity to health and disease has grown rapidly over the past few decades. Epidemiological studies on this issue follow the pattern of evaluating the relation of physical activity or fitness to fatal or nonfatal disease end points and, more recently, to functional disability. Various study designs, including retrospective, cross-sectional, and prospective approaches, have been used, and dependent variables such as cardiovascular disease, cancer, diabetes, osteoporosis, obesity, hypertension, stroke, musculoskeletal disability, and all-cause mortality have been examined. More than 100 large population-based studies on the relation of physical activity or fitness to health have been published in the peer-reviewed literature, most appearing in the past 30 years. Table 1 briefly summarizes this research. Substantial evidence supports the hypothesis that sedentary habits increase the risk of morbidity and mortality from a number of chronic diseases. The strongest evidence for a causal association is for coronary artery disease, hypertension, colon cancer, obesity, functional capability, and non-insulin-dependent diabetes mellitus. Lower risk of mortality from all-causes and an increase in longevity also accompany a physically active way of life.
Table 1. Summary results of studies investigating the relationship of physical activity or physical fitness to selected chronic diseases or conditions, 1963-1993
Trends across activity or fitness categories Number and strength Disease or condition of studies(a) of evidence(b) All-cause mortality *** [3 arrow down] Coronary artery disease *** [3 arrow down] Hypertension ** [2 arrow down] Obesity *** [2 arrow down] Stroke ** [1 arrow down] Peripheral vascular disease * [right arrow] Cancer colon *** [2 arrow down] rectum *** [right arrow] stomach * [right arrow] breast * [1 arrow down] prostate ** [1 arrow down] lung * [1 arrow down] pancreas * [right arrow] Non-insulin-dependent diabetes * [2 arrow down] Osteoarthritis * [right arrow] Osteoporosis ** [2 arrow down] Functional capability ** [2 arrow down]