Knes 303 lecture 13 physiological sex-related differences in aerobic exercise. Peripheral components: mitochondria function, muscle metabolism, muscle blood flow (bf, muscle fiber type expression, muscle strength capacity. Lower capacity to pump blood into the system due to cardiac structural differences: probably, the lower vo2max in women is due to lower co capacity. The lower co is a result of smaller heart size and stroke volume capacity. Lower vo2max even when corrected by the fat- free mass: but the correction reduces the sex differences. In order to expand the thoracic region, it takes more energy from women vs men. Blood o2 carry capacity: women have a lower amount of hemoglobin and thus they have less. This results in lower o2 delivery to the active tissues during exercise. Whole body muscle metabolism during exercise: figure 1: greater fatty acids oxidation when exercising at @50% vo2max for 90 min.