The results also "showed that being active, keeping a normal BMI and not smoking were associated with substantially higher levels of cardiorespiratory fitness during the adult life span studied," the authors write. "Being inactive and having a high BMI were associated with a lower age at which an individual could be expected to reach threshold cardiorespiratory fitness levels associated with substantially higher health risks."

Given the high rates of obesity and low levels of physical activity previously observed in the general population, the results also suggest that more men and women will reach the fitness level designated by the Social Security Administration as representing disability at a younger age, the authors note. "These data indicate the need for physicians to recommend to their patients the necessity to maintain their weight, engage in regular aerobic exercise and abstain from smoking," they conclude.

pubs.ama-assn/