Never Too Late
It may not be too late to benefit from exercise, even for people in their 60s and older, according to scientists at the National Institute on Aging (NIA) Gerontology Research Center. They found that an aerobic exercise program for sedentary older people improves cardiovascular function regardless of prior physical conditioning.
Age is a major risk factor for cardiovascular disease. The numbers of cases of heart disease and stroke rise steeply after age 65, accounting for more than 40% of all deaths among people age 65 to 74, and almost 60% at age 85 and above.
Older people have less reserve mechanisms to augment their heart function during physical activities than younger people do, said Edward Lakatta, M.D., Chief of the Laboratory of Cardiovascular Science at the NIA and the study’s principal investigator. But aerobic exercise conditioning can offset normal aging of the heart by making it a better pump, even for those who begin later in life, at age 60 or 70. In other words, points out Lakatta, you don’t lose the ability to get into condition. You can improve your heart’s pump function, which declines with aging.
Aerobic Exercise Helps At Any Fitness Level
Previous studies have shown that older people can benefit from aerobic exercise, but a novel aspect of the NIA study found that the relative benefits were the same regardless of how fit they were when they started exercising, said Lakatta. For example, at maximum capacity, older athletes’ heart function seems to be closer to that of younger men than to that of older men who do not exercise regularly.
But a decline in maximum heart rate with aging is unaffected by conditioning, said Lakatta. With age, the hearts of otherwise healthy sedentary people gradually lessen their ability to increase their heart rate during acute exercise.
The National Institute on Aging, part of the National Institutes of Health, leads the federal effort supporting basic, clinical, epidemiological and behavioral research on aging and the special needs of older people.
Lift Weights To Boost Aging Metabolism
A comprehensive study might allay any lingering debate about why metabolism slows as people age. The findings show that the gradual loss of body cells, especially those high-energy-consuming muscle cells, can help explain why older people burn fewer calories while at rest – which so often leads to creeping weight gain.
Some scientists have suggested that changes in hormones, immune function or other factors may depress resting metabolism with aging. But a study published in the Journal of Gerontology: Medical Sciences (Vol. 55A, pp. M757-760) showed a direct association between metabolic rate and cell mass, also known as lean- or fat-free mass. And that means that older people may regain some of their youthful resting metabolic rate and get off the slow boat to obesity by regular muscle-building exercises. Increasing muscle mass would help seniors, according to the researchers.
They analyzed measurements of body composition and resting metabolic rate for 131 healthy men and women taken over a five-year period at the Boston center. The subjects ranged in age from 18 to 87, giving the researchers a broad sample for detecting small changes in cell mass across the years. But they found that only 1 of the 6 methods used to measure the subjects' body composition exposed the decline in cell mass occurring with age. That was a high-tech method for measuring the body's total potassium – a mineral found almost entirely inside of cells.
Related studies at the center further support an age-related loss of cell mass. Researchers found a definite decline in muscle mass of middle-aged and senior men and women over 10- and 12-year periods when they measured the subjects' leg muscles by computerized tomography – or CAT scan. The shrinkage of muscle tissue explained at least half of the subjects' loss of strength in those muscles.
This article includes information from:
US Department of Agriculture/Agricultural Research Service
National Institute on Aging
