Being in shape helps to prolong your life, even if you are overweight and even if you store fat primarily in your belly, which is a major risk factor for diabetes, heart attacks, and probably certain types of cancers ( JAMA , December 5, 2007). As people age, most gain weight and become progressively less active. Researchers at the University of South Carolina in Columbia showed that a person's fitness level was a far stronger predictor of premature death than body fat. Those who were fit suffered less than half the death rate of those who were out of shape. They also showed that those who store fat primarily on their bellies are at significantly greater risk for dying early and that people with abdominal obesity who exercise are far less likely to die early than those who did not exercise.
The authors describe fitness as walking briskly at least five days a week. Abdominal obesity is defined as having a waist circumference over 40 inches for men or 35 inches for women. In this study, the least fit 20 percent had a death rate twice as high as people who did 30 minutes of walking five days a week. Those who were more fit had an even lower death rate. Furthermore, higher levels of fitness were inversely related to all causes of death in both the normal-weight and overweight groups.