Tuesday, October 20, 2009
Which is more important for healthy aging: exercises that work the heart and lungs, or muscle- pumping strength training? Both are valuable, of course, but many experts now say strength training may be the key to preventing disability as you age. Declining muscle mass not only undermines your physical strength but also contributes to heart disease, Type 2 diabetes and other chronic illnesses by slowing the body's metabolic rate, encouraging the accumulation of fat.
This decline in muscle mass begins surprisingly early, usually by age 40. And between ages 50 and 70, muscle strength can drop by 15 percent per decade, even faster in later years. Although this loss was previously considered an inevitable part of aging, strength training can halt much of that decline and restore muscle power to the levels you had decades earlier.
No matter how old you are, your muscles will respond quickly to resistance training, a form of strength training. In clinical trials, women and men in their 80s and older who started resistance training gained strength as rapidly as when younger adults did the same exercises. Plus, the latest research suggests that regularly challenging your muscles may spur changes at the cellular level that may slow some causes of aging.
A recent study of about 9,000 men ages 20 to 82, for example, found that those with the greatest leg and arm strength were nearly 25 percent less likely to die prematurely than those with the least strength. The benefits of muscle strength stood out even after accounting for differences in aerobic fitness, suggesting that muscle training provides benefits beyond helping with heart and lung endurance.
Consumer Reports outlines why strength training is important. It:
Pumps up the heart. Strength training's cardiovascular benefits are so pronounced that it has become a standard part of heart-attack rehabilitation.
The benefits were shown in a recent trial where researchers randomly divided 72 men and women with heart disease into two groups. One did aerobic exercises five days a week; the other did three days of aerobics plus two days of strength training with dumbbells and elastic bands. Even though the weightlifting groups did about 30 percent less aerobic training, they reached the same level of aerobic fitness as the other group by the end of the seven-month study. And strength training included some benefits for the mixed-exercise group that weren't seen in the aerobics-only group: significant reduction in body fat and substantial gains in muscle strength and endurance.
Other clinical trials found resistance training may also reduce high blood pressure.
Wards off diabetes. Aerobic training and resistance exercises improve the body's ability to manage blood sugar. And exercisers may reap the most benefit by combining the two, according to a study published this year. The study looked at 136 people between ages 60 and 80 at high risk for Type 2 diabetes because of excess weight. After the study, researchers concluded that resistance training helps by building muscle and reducing fat. This shift may allow the body to control blood sugar more efficiently.
Builds bone. To maintain their density, bones need to be exercised. That includes being stressed by weight or some other resistance. Walking, dancing and other weight-bearing aerobic activities can build bone in the hips, for example.
For other parts of the body, strength-training exercises appear to be most effective. In cases where you want to prevent spinal fractures, try exercises targeting the back and abdomen. Leg exercises are important because they improve balance, preventing falls. But before starting an exercise regimen, people with severe osteoporosis should consult a physical therapist, who can recommend exercises that don't overly stress bones.
Prevents cancer. The study that linked muscle strength to improved overall mortality in men also noted a reduced risk of death from cancer for those with greater leg and arm strength. The researchers theorized that strength training protects against malignant tumors by boosting metabolism, which may prevent the buildup of fat.
Increases mobility. It's known that strength training makes it easier to handle everyday tasks such as lugging groceries and climbing stairs. A related but lesser-known benefit is that this training helps relieve joint pain. In a recent clinical trial of weight training for people with knee arthritis, for example, pain scores were cut nearly in half and walking speed over uneven ground increased by nearly 50 percent after eight weeks. No improvements were seen in the control group.
Resistance training strengthens ligaments, muscles and tendons, making ankles, hips and knees more stable. It also reduces stress on the joints, which may protect cartilage from age-related degeneration. Moreover, pressure on the joints during resistance training may spur the growth of new cartilage, thereby protecting hips and knees.
Copyright 2009 Consumers Union of United States Inc.
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