A computer assisted literature search was performed (Medline, 1966–2000) to examine the association of physical activity with all cause mortality in women. It was concluded that, by adhering to current guidelines for physical activity and expending about 4200 kJ of energy a week, women can postpone mortality. The magnitude of benefit experienced by women is similar to that seen in men.

No abstract

Background-Current recommendations prescribe at least moderate-intensity physical activity, requiring Ն3 METs (metabolic equivalents) for Ն30 minutes almost daily, generating Ϸ1000 kcal/wk. Defining intensity using an absolute scale in METs may be limited because it neglects variations in physical fitness: an activity requiring a particular MET value commands greater physical effort among less fit than more fit persons. It is unknown whether moderate-intensity exercise, relative to an individual's capacity, is associated with reduced coronary heart disease (CHD) rates. Methods and Results-We followed 7337 men (mean age, 66 years) from 1988 to 1995. At baseline, men reported their actual activities and, using the Borg Scale, the perceived level of exertion when exercising (relative intensity). During follow-up, 551 men developed CHD. After multivariate adjustment, the relative risks of CHD among men who perceived their exercise exertion as "moderate," "somewhat strong," and "strong" or more intense were 0.86 (95% confidence interval, 0.66 to 1.13), 0.69 (0.51 to 0.94), and 0.72 (0.52 to 1.00), respectively (P trend ϭ0.02), compared with "weak" or less intense. This inverse association extended to men not fulfilling current recommendations, ie, expending Ͻ1000 kcal/wk in physical activity or not engaging in activities of Ն3 METs (P trend ϭ0.03 and 0.007, respectively). Conclusions-There is an inverse association between relative intensity of physical activity (an individual's perceived level of exertion) and risk of CHD, even among men not satisfying current activity recommendations. Recommendations for "moderate"-intensity physical activity may need to consider individual fitness levels instead of globally prescribing activities of Ն3

Physical activity improves health, and current recommendations encourage daily exercise. However, little is known about any health benefits associated with infrequent bouts of exercise (e.g., 1-2 episodes/week) that generate the recommended energy expenditure. The authors conducted a prospective cohort study among 8,421 men (mean age, 66 years) in the Harvard Alumni Health Study, without major chronic diseases, who provided details about physical activity on mailed questionnaires in 1988 and 1993. Men were classified as "sedentary" (expending <500 kcal/week), "insufficiently active" (500-999 kcal/week), "weekend warriors" (>/=1,000 kcal/week from sports/recreation 1-2 times/week), or "regularly active" (all others expending >/=1,000 kcal/week). Between 1988 and 1997, 1,234 men died. The multivariate relative risks for mortality among the sedentary, insufficiently active, weekend warriors, and regularly active men were 1.00 (referent), 0.75 (95% confidence interval (CI): 0.62, 0.91), 0.85 (95% CI: 0.65, 1.11), and 0.64 (95% CI: 0.55, 0.73), respectively. In stratified analysis, among men without major risk factors, weekend warriors had a lower risk of dying, compared with sedentary men (relative risk = 0.41, 95% CI: 0.21, 0.81). This was not seen among men with at least one major risk factor (corresponding relative risk = 1.02, 95% CI: 0.75, 1.38). These results suggest that regular physical activity generating 1,000 kcal/week or more should be recommended for lowering mortality rates. However, among those with no major risk factors, even 1-2 episodes/week generating 1,000 kcal/week or more can postpone mortality.