to do only the minimum. A recent Harvard study of more than 40,000 men ages 40 to 75 suggested that, the higher the intensity of one’s exercise, the greater one’s chance of avoiding heart disease.
In the study, men who participated in high-intensity cardiovascular exercise (such as running or jogging at 6 miles per hour) were 17 percent less likely to develop heart disease than those who participated in low-intensity exercise (such as walking at only 2 miles per hour). In fact, the study showed no significant heart benefits from low-intensity walking.
The research also showed an improvement in subjects’ heart health due to weight training. Because anaerobic exercise (such as weight training) does not provide the heart and lungs the kind of workout provided by cardiovascular exercise (such as brisk walking or running), researchers have differed on its impact on the heart. However, in the study, men who lifted weights for 30 minutes or more weekly had a 23 percent lower risk of heart disease than those who did not lift weights, possibly because of the reductions in blood pressure and body fat due to weight training. Indeed, the researchers suggest that the combination of weight training and high-intensity cardiovascular exercise would maximize the benefit for heart health.
Gerald Fletcher, MD—spokesman for the American Heart Association (AHA) and cardiologist at the Mayo Clinic in Jacksonville, Florida—said, “The more exercise you do and the higher intensity seems to be better with regard to cardiovascular protection.” According to Fletcher, the findings of the study agree with AHA guidelines, which recommend cardiovascular exercise at least 6 days per week and weight training two or three times per week.
Nonetheless, the key is simply to strive always to do more. “A little is better than sitting in front of the television,” Fletcher said.