March 15, 2009
Men who start or increase their exercise programs after age fifty live longer than those who remain at their present activity levels, according to a study in the British Medical Journal (March 2009). More than 2200 men were checked at ages 60, 60, 70, 77 and 82 years. The greater the increase in exercise duration over that span, the longer their lives were extended. The reduction in early death from increasing exercise was the same as for men who stopped smoking.
Lack of exercise is associated with obesity, diabetes, heart attacks, strokes, osteoporosis, and cancer. Exercising regularly more than halves your chance of dying prematurely (Archives of Internal Medicine, December 2007). Yet more than 50 percent of North Americans do not exercise.
Exercise prevents disease and increases life span by many mechanisms. The major benefit probably comes from the contracting muscles themselves. A high rise in blood sugars and fats after meals damages cells. When blood sugar levels rise too high, sugar sticks to the surface of cell membranes. Once there, it can never get off, eventually killing the cells and leading to blindness, heart attacks, strokes and the other consequences of uncontrolled diabetes. Contracting muscles draw sugar and fat so rapidly from the bloodstream that they usually prevent blood sugar levels from rising too high. This effect is maximized during exercise. The effect is maintained for about half hour after you stop exercising and gradually tapers off until it disappears after about 18 hours. That explains why you get maximum benefit by exercising every day (rather than three times a week), and why greater benefit is gained by exercising more intensely for longer durations.
