Over the past 50 years or so, many epidemiologic studies have examined the
association between physical activity or physical fitness and coronary hear
t disease (CHD) risk Their findings have been consistent, showing that phys
ically active or fit men and women experience lower CHD risk than those who
are sedentary or unfit. On average, active patients have half the risk of
sedentary patients. Data regarding the optimal amount, intensity, and durat
ion of physical activity required to decrease CHD risk have been less clear
. It appears that following recent recommendations-at least 30 minutes of m
oderate-intensity physical activity (such as brisk walking) on most days-is
sufficient.