THE IMPORTANCE OF PHYSICAL-FITNESS VERSUS PHYSICAL-ACTIVITY FOR CORONARY-ARTERY DISEASE RISK-FACTORS - A CROSS-SECTIONAL ANALYSIS

Numerous epidemiological investigations have shown that low physical f itness and low physical activity are related to the incidence of coron ary artery disease (CAD). Most studies, however, have not examined bot h variables concurrently to determine which has the strongest associat ion with CAD risk. The purpose of this investigation was to cross-sect ionally examine the relationships among physical fitness, physical act ivity, and risk factors for CAD. Male law enforcement officers (N = 41 2) from the City of Austin, Texas, were subjects for this study. Physi cal fitness, physical activity, and risk factors for CAD were assessed through health screenings and from data collected as part of an annua l physical fitness assessment. Multivariate analysis of covariance rev ealed that physical fitness, but not physical activity, was related to several single CAD risk factors. Percent body fat, smoking habits, an d Type A behavior score were negatively related to physical fitness le vel, and high density lipoprotein (BDL) cholesterol was positively rel ated to physical fitness level. Univariate analysis of variance found both physical fitness and physical activity to be significantly relate d to a composite CAD risk score. Low physical fitness and low physical activity were associated with a high CAD risk score. These data sugge st that physical activity must be sufficient to influence physical fit ness before statistically significant risk-reducing benefits on single CAD risk factors are obtained, although minimal engagement in weekly vigorous activity provides a significant benefit for the composite CAD risk score. It is plausible, however, that physical fitness is a stro nger measure than physical activity and optimally characterizes the re lationship among physical activity and CAD risk factors.