Variations in maximal oxygen intake with physical activity in middle-aged men.

Data on maximal exercise performance are presented for normal middle-aged men free of cardiovascular disease. Maximal oxygen intake, oxygen pulse, heart rate, and lactate levels all decrease with increasing age. Physical activity defined by habitual running of any amount had a highly significant effect on maximal oxygen consumption. The enhanced effect of physical activity was found equivalent to nearly 10 years of age effect on maximal aerobic capacity. Multivariate analysis revealed significant association between maximal oxygen intake and several coronary risk factors; specifically, physical activity, vital capacity, cigarette smoking, and body weight. Notably lacking in significance wer…