NO doubt you've heard about spectacular athletic accomplishments by the elderly such as the California physician Paul Spangler, who began running at age 67 and went on to set more than 40 records by age 85. Or the tennis champion Kirk M. Reid, who at 80 was still winning national tournaments. Although these are unusual people in exceptionally good physical condition, their stories have significance for older men and women with far less athletic prowess.
Today, growing numbers of older Americans who were never particularly active in their younger years are taking up exercise with a vengeance. Millions of Americans over 50 are now running, dancing, cycling, swimming and walking their way to a healthier, more fulfilling life. Not to mention those who continue to play tennis, racquetball, handball and other demanding sports long after most of their contemporaries have become content to sit on the sidelines.
The results of this national exercise fever - which includes all age groups - have been both good and bad. Physical activity appropriately pursued at any age can unquestionably add life to years and possibly years to life. Even among people with chronic ailments such as heart disease or arthritis and people using wheelchairs or those confined to bed, an exercise regimen improves physical and mental well-being.
Unfortunately, some older people become so hooked on the rejuvenating effects of physical activity that they endanger themselves by doing too much too soon; others don't do a broad enough spectrum of exercise to reap its full benefits with the least possible risk. The older one gets, the more important it is to heed the cautions that traditionally accompany strenuous activity at any age. And for older people, there are special precautions to prevent injuries that are more likely to occur later in life.
What kinds of exercise and how much? There are three major types of exercise, and all are important in maintaining the highest possible quality of life for however long a person lives.Continue reading the main story
* Endurance activities condition the cardiovascular and respiratory systems and enable a person to do more physical work with less effort and less strain on vital organs.
* Strengthening exercises increase the power of muscles, which permits greater, safer and more sustained muscular effort and, even more important, helps protect the joints against injury.
* Flexibility or stretching exercises keep aging joints from stiffening. Researchers have shown that most of the joint stiffness and aches and pains that accompany aging are the result of disuse, not of arthritis or an unavoidable age-related deterioration of tissues.
The basic recommendation for endurance exercise is to pursue an activity or activities for 30 continuous minutes at least three times and at most five times a week. This is not to say that a healthy older person who has been vigorously active every day for years must cut back with advancing age; but such a person might be wise to reduce the intensity of each workout and to introduce variety so that different parts of the body are used on different days.
Activities that bring conditioning benefits use the long muscles of the body, which are in the legs, arms and trunk, in a rhythmic fashion for at least 20 continuous minutes. Heart and breathing rates should increase, and the exerciser should work up a sweat.
The ideal activity for most older people is brisk walking at a pace of three to five miles an hour. Swimming laps can also be excellent if done rapidly and continuously. So is using a stationary bicycle, indoor ski track or rowing machine. But to prevent injury to the knees and ankles, most experts advise that the elderly avoid vigorous jogging, rope jumping, aerobic dancing and other activities that involve jumping or pounding motions.
As people get older, optimum endurance benefits are attained at less strenuous levels of activity. A person under 50 is usually advised to exercise at a heart rate that is 70 to 85 percent of the maximum rate for the person's age, but older exercisers can achieve peak cardiovascular conditioning by exercising at only 60 to 75 percent of maximum heart rate for at least 20 minutes at a time at least three times a week. When swimming, however, do not go above 60 percent of your maximum heart rate.
To determine your maximum heart rate, subtract your age from 220. Determine the target heart rate for exercise by calculating 60 percent and 75 percent of the resulting number, and do not exceed the latter number during your endurance workout. For example, if you are 70 years old: 220 minus 70 equals 150 beats per minute, your maximum heart rate; 150 times 0.60 (60 percent) equals 90, your minimum heart rate during exercise, and 150 times 0.75 (75 percent) equals 112, the highest heart rate you should sustain.
Strengthening exercises need be done only two or three times a week to increase muscle strength by 40 to 75 percent over several months. In fact, you might consider working your muscles against resistance on your days off from endurance training.
You can use lightweight hand and leg weights, building gradually from perhaps 10-ounce weights (such as a can of soup), or work out on weight machines (such as Nautilus or Universal). Exercises such as leg lifts, finger presses and bent-leg situps can also be done.
Flexibility exercises are best done daily, but significant benefits can be achieved with just three sessions a week. The single most important rule in stretching the body's soft tissues (muscles, ligaments and tendons) is to hold the stretched position for at least a count of 10. Then relax for a moment and repeat. Bouncing when stretching is counterproductive; it tightens, not stretches, soft tissues.
How to exercise safely. Dr. Herbert A. deVries, exercise physiologist in Laguna Hills, Calif., and author with Dianne Hales of ''Fitness After 50'' (Scribner's, 1982), calls these elements essential to a safe and effective exercise regimen for older adults:
* See your doctor. A medical checkup is extremely important before beginning an exercise program, especially if you have been relatively sedentary in recent years, if you have any chronic health problem or if you are taking medication. If you want to increase the intensity of an exercise program you have begun, see your doctor again. The doctor may well recommend an exercise stress test to see how well your heart performs during endurance-promoting activities.
* Take it slow. Start at a low, comfortable level of exertion and increase its intensity very gradually. You might start by walking only half a mile and, over a period of 6 to 12 months, work up to three miles of walking and light jogging alternately.
* Know your limit. If you have excessive fatigue, sleep problems or persistent muscle soreness, you are probably trying to do too much. Check your pulse several times during your workout to be sure you are not exceeding the recommended limit for your age. If you have difficulties exercising at 60 percent of your heart's maximum rate, exercise at a lower intensity but do it longer. Older people can obtain significant benefits from exercise at just 40 percent of capacity.
* Exercise regularly. It takes many weeks to reach a peak level of conditioning, but it can be lost in a week or two of inactivity. Try to maintain an exercise schedule of at least three workouts a week. But stop your program if you become ill, even if it is only a cold. If illness or other circumstances preclude exercise for a week or more, resume at a lower level of intensity and gradually work back up.
* Warm up first. The older you are, the more important it is to prepare the body for intense exercise. A proper warm-up of about 10 minutes protects the heart, muscles and joints from injury. After your muscles are warm, you might do some flexibility exercises before beginning a conditioning workout.
* Cool down afterward. Never stop vigorous exercise abruptly. The muscle action that is the pump for about a third of the body's circulation is suddenly lost, and the heart may not receive enough blood, a potentially fatal condition. Walk for at least two minutes after a walk-jog, for example. And never take a hot shower or sauna after a vigorous workout; the heat opens up blood vessels and can lead to circulatory collapse. Wait at least five minutes before showering and keep the water warm, not hot. FURTHER READING
IN addition to the excellent book ''Fitness After 50,'' you might consult the ''Medical and Health Guide for People Over Fifty,'' prepared by the Dartmouth Institute for Better Health and published this year by the American Association of Retired Persons ($14.95), and ''Pep Up Your Life,'' a fitness booklet for the elderly published by the Travelers Insurance Companies, 1 Tower Square, Hartford, Conn. 06115.Continue reading the main story