How much not how hard.

• Position: Exercise - Brief article

The amount of exercise a person engages in per week may be more important than the intensity of the workouts. A study by Duke University, Durham, N.C., shows that adults who participate in mild exercise, such as walking briskly for 12 miles or working out for 125-200 minutes a week at moderate intensity significantly can improve aerobic fitness and reduce the risk of cardiovascular disease. Unlike most exercise interventions, this finding suggests that amount may be equally as, or more important than, intensity.

"The classic exercise regimen has a component of intensity up to 80% of someone's maximum for health benefits. Our study demonstrates that you can exercise at an intensity much less than that and still achieve fitness benefits," contends lead author Brian D. Duscha of the Duke University Medical Center. "People find exercise 'hard' and few people want to exercise at an intensity higher than they have to. Walking briskly for 12 miles a week per week is realistic and does not require anyone to incorporate a hardcore training regimen.

"Although our results did point toward...