NEW YORK, Mar 28 (Reuters Health) -- If you are in your 60s and 70s and in good health, vigorous aerobic exercise may be the best way to improve your cardiovascular health, researchers report.

In a study of 117 healthy men and women aged 59 to 77, investigators found that subjects' aerobic capacity, rather than the number of calories they burned through exercise, was strongly linked to heart disease risk.

The men and women who had the greatest aerobic capacity were leaner and had lower cholesterol and insulin levels compared with their peers, report Dr. Eric T. Poehlman, of the University of Vermont in Burlington, and colleagues in the Journal of Clinical Endocrinology and Metabolism.

Those who were aerobically fit -- a measure of the body's ability to transport and use oxygen -- appeared to be at lower risk of heart disease regardless of whether or not they exercised more or less than other study subjects. This, Poehlman told Reuters Health, suggests that bursts of exercise that get the heart and lungs working at peak capacity may benefit elder hearts more than frequent, moderate activity.

With a doctor's approval, he noted, some elderly people may be better off engaging in vigorous exercise.

According to Poehlman and his colleagues, there has been considerable controversy about how much older men and women should exercise, and what types of activity they should engage in. It has not been clear which is more important -- aerobic fitness or calorie-burning exercise. The authors note that these two factors do not necessarily go hand-in-hand.

To directly compare the two factors, the researchers measured subjects' aerobic capacity on a stationary bike and gauged their calorie burning over 10 days. They also looked at participants' body composition and dietary intake over 3 days. The men and women were then divided into groups based on high and low aerobic capacity, and high and low calorie burning.

Across all groups, the investigators found, participants' activity levels surpassed the general recommendation that older adults burn about 200 calories each day through exercise. Yet only those with high aerobic capacity showed a reduction in many heart disease risk factors.

Those with a high level of physical activity alone (without being aerobically fit) had a reduction in only one heart disease risk factor -- a drop in LDL (or "bad") cholesterol.

Because the aerobically fit had less abdominal fat than other subjects, the researchers speculated that this may be the reason for their reduced heart disease risk.

These findings do not, according to Poehlman, discount the benefits of moderate exercise. Such exercise increases calories use but does not push the heart rate to a maximum. Low-intensity exercise, he noted, helps people regulate their weight and protects against diseases, such as type 2 diabetes.

SOURCE: Journal of Clinical Endocrinology and Metabolism 2000;85:957-963.

http://www.doctorbob.com/ - 03/31/2000