Prime Time - Jane Fonda [37]
Earlier I mentioned how aerobic exercise releases endorphins, brain chemicals that give relief from pain, enhance the immune system, reduce stress, and bring us a sense of well-being. Some people need only ten minutes of moderate exercise to experience the endorphin rush; others might require thirty minutes. The effect is often called a “runner’s high,” and it is one reason why physical activity is increasingly becoming part of the prescription for the treatment of depression and anxiety—a beautiful side effect of exercise that motivates many of us to keep doing it.
What About Weight-Training Exercise
for People over Fifty?
Weight lifting—or resistance training, as it’s sometimes called—is great for people over fifty, even essential! While it doesn’t increase your endurance the way aerobic exercise does, it does maintain or increase the size and strength of your muscles, and there are several reasons why this is important at any age.
For one thing, increasing your muscle mass helps you lose weight, because muscles are the active tissues in the body. They determine your basal (or resting) metabolism rate, the rate at which your body burns caloric energy. Muscle tissue turns your body into a calorie-burning machine even when you’re resting.
We tend to put on weight as we get older. This is due partly to our tendency to be less active while continuing to eat the way we always have. But it is also due to the fact that we lose, on average, 3 to 5 percent of our muscle tissue each decade after age thirty. This means that by the time we reach seventy-five, our resting metabolism (basal metabolism) will have dropped by about 10 percent—unless, of course, we become active enough to maintain our muscles. In either case, we should also consciously eat fewer (but more nutrient-rich) calories.
Here’s a dramatic example of what can happen: If you eat just one hundred calories more than you burn up every day, you can expect to gain more than fifty pounds in five years. In order to lose this fat, you have to burn it up as a source of energy. (That is, if the calories you eat are fewer than the number of calories you are burning as energy, then the additional energy you need will have to come from stored fat.) To sum up: Aerobic or fat-burning types of activities will help with weight loss, as will increasing your resting metabolism rate through weight-training or resistance exercise to maintain your muscle mass. According to research done at Tufts University on people fifty to seventy-two years old, muscle mass can actually be increased by more than 200 percent with exercise.
Weight Training and Your Bones
Lifting weights or doing resistance training with elastic resistance straps or tubing will not only maintain or increase your muscle mass, it will also improve the strength of your bones, which, in turn, will reduce your risk of osteopenia and osteoporosis, the loss of bone mineral density.
The Tufts study that reported increased muscle mass in older people through resistance training also reported that bone mass can similarly be increased. This is important because osteopenia and the more advanced condition osteoporosis put us at greater risk of fractures, especially of the hip, wrist, ankle, and spine. There are more than 250,000 hip fractures in the United States every year, 80 percent of them to women, and, in 10 to 15 percent of older people, these fractures can lead to death. Something else that is increasingly important with age is the fact that strong muscles can reduce stress on the joints.
Weight Training and Your Brain
Researchers in British Columbia found that women who did an hour or two of weight training every week had better cognitive function than those who did only balance and toning exercises. After one year, the women who lifted weights scored higher in the ability to make decisions, resolve conflicts, and stay focused.5 As Dr. Michael Hewitt, the research director for exercise science at