What Is the Evidence?

Exercise can enhance glucose metabolism, preventing the onset of type 2 diabetes. One study (Manson et al. 1991) looked at nearly 90,000 middle-aged women over an eight-year period. The results demonstrated that those who exercise vigorously at least one time per week have a lower risk of developing diabetes. The same study also showed that those who exercise and are significantly overweight have a similar benefit. A more recent study (Hu et al. 1999) looked at 70,000 people and found that the exercise does not have to be as vigorous as once thought to have the same preventive effects.

Through many studies we have found that exercise also decreases heart disease risk. One study of women (Lee et al. 2001) demonstrated that light to moderate activity is associated with decreased heart disease. But regardless of sex or health status, most people who exercise will improve their blood pressure and cholesterol, reduce body fat, and reduce glucose levels-hat is, they will experience changes that are especially important for those with diabetes. We also have evidence that shows that exercise may decrease symptom anxiety, relieve depression, improve work productivity, and reduce the risks for certain types of cancer.