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.
