Exercise type and intensity in relation to coronary heart disease in men

Context Studies have shown an inverse relationship between exercise and risk of coronary heart disease (CHD), but data on type and intensity are sparse. Objective To assess the amount, type, and intensity of physical activity in relation to risk of CHD among men. Design, Setting, and Participants A cohort of 44452 US men enrolled in the Health Professionals' Follow-up Study, followed up at 2-year intervals from 1986 through January 31, 1998, to assess potential CHD risk factors, identify newly diagnosed cases of CHD, and assess levels of leisure-time physical activity. Main Outcome Measure Incident nonfatal myocardial infarction or fatal CHD occurring during the follow-up period. Results During 475755 person-years, we documented 1700 new cases of CHD. Total physical activity, running, weight training, and rowing were each inversely associated with risk of CHID. The RRs (95% confidence intervals [CIs]) corresponding to quintiles of metabolic equivalent tasks (METs) for total physical activity adjusted for age, smoking, and other cardiovascular risk factors were 1.0, 0.90 (0.78-1.04), 0.87 (0.75-1.00), 0.83 (0.71-0.96), and 0.70 (0.59-0.82) (P<.001 for trend). Men who ran for an hour or more per week had a 42% risk reduction (RR, 0.58; 95% CI, 0.44-0.77) compared with men who did not run (P<.001 for trend). Men who trained with weights for 30 minutes or more per week had a 23% risk reduction (RR, 0.77; 95% CI, 0.61-0.98) compared with men who did not train with weights (P=.03 for trend). Rowing for 1 hour or more per week was associated with an 18% risk reduction (RR, 0.82; 05% CI, 0.68-0.99). Average exercise intensity was associated with reduced CHD risk independent of the total volume of physical activity. The RRs (95% CIs) corresponding to moderate (4-6 MET's) and high (6-12 METs) activity intensities were 0.94 (0.83-1.04) and 0.83 (0.72-0.97) compared with low activity intensity (<4 ME Ts) (P=.02 for trend). A half-hour per day or more of brisk walking was associated with an 18% risk reduction (RR, 0.82; 95% CI, 0.67-1.00). Walking pace was associated with reduced CHD risk independent of the number of walking hours. Conclusions Total physical activity, running, weight training, and walking were each associated with reduced CHID risk. Average exercise intensity was associated with reduced risk independent of the number of MET-hours spent in physical activity.