Determinants of Cardiorespiratory Fitness in Men Aged 42 to 60 Years With and Without Cardiovascular Disease

Good cardiorespiratory fitness has been found to protect against cardiovascular diseases and type 2 diabetes. The purpose of this study was to investigate determinants of directly measured cardiorespiratory fitness (maximal oxygen uptake [Vo 2max ]), including age, body composition, prevalent diseases, cardiovascular and pulmonary functions, biochemical factors, physical activity, nutrition, smoking, and alcohol consumption, in a population-based study of 936 men 42 to 60 years of age. Variables that had the strongest direct associations with Vo 2max (milliliters per minute) in a linear multivariate step-up regression model were body weight, heart rate at maximal exercise, mean intensity and frequency of conditioning physical activity, intake of carbohydrates, blood hemoglobin, and forced expiratory volume in 1 second. The strongest inverse associations with Vo 2max were heart rate at rest, age, fasting serum insulin, waist-to-hip ratio, coronary heart disease, and asthma. This model accounted for 67% of the variation of Vo 2max . In conclusion, mean intensity, frequency, and duration of conditioning physical activity were associated directly with Vo 2max . However, measurements of the function of pulmonary and cardiovascular systems, carbohydrate intake, and body composition were powerful determinants of cardiorespiratory fitness, especially in older middle-aged men.