WASHINGTON — As long as they're healthy, adults of any age should be encouraged to exercise, because studies show that it's a safe way to improve their cardiovascular health.
“It turns out that healthy older adults are able to make the necessary cardiovascular adjustments—and physiological homeostasis is preserved—and they are able to exercise effectively,” said Douglas Seals, Ph.D., a physiologist who studies aging and exercise at the University of Colorado, Boulder. He spoke at the annual meeting of the Society of Geriatric Cardiology.
“Aging will limit the absolute intensity and duration of submaximal aerobic exercise that can be performed by older adults…. However, performance of sustained submaximal exercise is not impaired by advancing age,” said Dr. Seals.
Dr. Seals cited a study that compared measurements during and after submaximal physical exertion in sedentary and trained groups of both healthy young men (aged 20–32 years) and healthy older men (aged 60–70 years). The volunteers walked on a treadmill for 60 minutes with enough effort to reach 70% of their maximum oxygen uptake, or VO2 max. Both groups of older men had smaller increases in heart rate and lower rates of perceived exertion than did the younger men. Plasma lactate responses, which can be used to indicate metabolic stress in muscles, were also smaller in the older men. Plasma catecholamine responses, which can show a physiological stress response to exercise, barely increased in any of the men (J. Appl. Physiol. 1988;65:900-8).
“One could reasonably interpret these data to mean that older adults undergo a smaller increase in physiological stress from the resting state, compared with young adults in submaximal exercise conditions,” said Dr. Seals.
He and his colleagues reinforced these findings in a similar study of young and elderly men during a 45-minute treadmill walk (Clin. Physiol. 1995;15:169-81). The older men had lesser increases in heart rate, internal body temperature, and plasma norepinephrine concentrations than did the younger group.
The take-home message is that older adults make the necessary cardiovascular adjustments to handle submaximal exercise, he said.