Fitness Slows Decline in Abilities : Older People Advised to Keep Exercising

The body’s ability to benefit from exercise changes little, even into the senior years, reports a scientist in a study of exercise and aging.

“There are some changes that accompany the aging process, but there are also some parameters that don’t change,” Herbert deVries said in a discussion of his work at the American Corrective Therapy Assn.’s annual conference here recently.

Even people who did not exercise regularly through their younger years have not lost much by the age of 40, said deVries, who was director of the Physiology of Exercise Research at the University of Southern California for 16 years.

As people move into their mid-60s, they have lost about one-quarter of their physical abilities but still can benefit from exercise, said deVries. He has written 60 research papers on health and fitness and his college text, “Physiology of Exercise,” is in its fourth printing.

Early research on aging showed that people lose about 1% of their physical ability per year from the age of 40 on. DeVries contends that regular exercise can reduce that loss by half.

In comparing the performance of youthful athletes with athletes ages 35 and older, deVries found about half of that 1% was related to the aging process, what he calls necessary loss.

The other half of 1 percent of the performance loss was from inactivity. That, he said, is unnecessary loss.

Over the years, that unnecessary loss can add up to a lot. Part of the reason older people feel they can do less work is because the small loss in muscle over the years becomes a big loss in oxygen-carrying ability later. Many older people don’t have enough muscle to load oxygen, deVries said.

Exercise benefits more than just muscle. Bone loss and breakdown is reduced, and joints that would become stiff instead become more flexible. Loss of standard reflexes, which can amount to 90% by age 75, is also reduced, he said.

Of course, a week of jogging workouts won’t make an old body young again.

DeVries found older athletes need about 12 weeks to reach half of their total capacity, a feat youthful counterparts accomplished in just a week and a half. But deVries credited much of this to the difference in flexibility between the two age groups.

“The influence of flexibility used to be overlooked, but it is being viewed as more important now,” he said.

Training programs have a major effect on whether the athlete will benefit. DeVries recommends working out six times a week, with three walking or jogging type workouts and three calisthenics sessions. Quick results should not be expected, however, deVries cautioned.

Deconditioned people--those who have not had any activity for several weeks--often show improvements more quickly than those who have had moderate exercise, deVries said.

Like other athletes, seniors do reach the point where performance does not improve. DeVries said he believes the training curve is shaped like an upside-down “U”, and that after a point, performance deteriorates.

For maximum benefit, deVries said the best policy is, “Use it or lose it, but don’t abuse it.”