Coronary risk factors and physical fitness in healthy middle-aged men.

In 1832 healthy men aged 40-59 years subjected to a near maximal bicycle exercise test, physical fitness decline with age. Higher levels of physical fitness were in all age groups associated with lower cigarette consumption, blood pressure, serum triglycerides, hemoglobin and with better pulmonary function. Serum cholesterol, however, was independent of changes in physical fitness. In view of the beneficial effect of high physical activity on the well-known coronary risk factors, it is surprising that it has proved so difficult to show a protective effect of increased physical fitness and activity in coronary heart disease and its manifestations.