How do aging, sex, and physical training affect cardiovascular responses to exercise?
The study highlights that while age and training effects on cardiovascular exercise capacity are independent of body composition, sex differences in sedentary individuals are primarily driven by body fat percentage.
A lower stroke volume, heart rate, and arteriovenous oxygen difference at maximal exercise all contribute to the age-related decline in VO2max. Effects of age and training on VO2max, maximal cardiac output, and stroke volume cannot be fully explained by differences in body composition. In sedentary subjects, however, the sex difference in maximal cardiac output and stroke volume can be accounted for by the greater percentage of body fat in women than in men.
Ogawa et al. (1992) studied this question.