Journal Watch Cardiology
January 3, 2003
Exercise in Men: Intensity vs. Amount

from Journal Watch
Physician-authored summaries and commentary
from the publishers of the New England Journal
of Medicine

Posted 02/19/2003


Summary

Many studies have linked exercise with reduced rates of coronary heart disease, but few have assessed the effect of exercise intensity on CHD risk. Investigators did just that by analyzing self-report data from 44,452 men (age range at baseline, 40-75) enrolled in the Health Professionals Follow-Up Study (1986-1998).

In analyses adjusted for typical CHD risk factors, exercise intensity was associated inversely with incident CHD: There was a 4% risk reduction for each 1-MET increase, independent of the total amount of exercise. Activity type also mattered: In analyses adjusted for traditional CHD risk factors and for other types of physical activity, high-intensity activities were associated with lower risk. For example, running at >/=6 mph for >/=1 hour/week was associated with 42% lower risk than no running. Also, weight training, a resistance exercise, for >/=30 minutes/week was linked with 23% lower risk than no weight training. Risk reduction was not evident for low-intensity activities (e.g., jogging at <6 mph for >/=1 hour/week). Fast walking pace was related to reduced CHD risk beyond -- and independent of -- a relation that was found for total walking amount.
Comment

These data suggest that high-intensity exercise and resistance exercise (including weight training) are associated with reduced risk for CHD events in men. Randomized trials must corroborate these findings. Current ACC/AHA guidelines recommend at least 30 minutes/day of aerobic exercise, but these new findings suggest that exercise intensity may need to be incorporated into the recommendations. Note that in a recent observational study of postmenopausal women, walking and vigorous exercise were found to have equal value for preventing adverse cardiovascular events; however, fast walking was associated with lower risk than slow walking (Journal Watch Cardiology Oct 11 2002).

— JoAnne M. Foody, MD
Source

Tanasescu M et al. Exercise type and intensity in relation to coronary heart disease in men. JAMA 2002 Oct 23/30; 288:1994-2000.