Optimizing both hemoglobin concentration and blood volume enhances VO2max and aerobic performance, with increased blood volume compensating for moderate reductions in hemoglobin.
Alterations in Hb, which are mediated through changes in arterial oxygen content, and alterations in BV, which are mediated through changes in cardiac output (Q), have a significant effect on both VO2max and aerobic performance. If BV is held constant, a decrease in Hb (anaemia) causes a decrease in VO2max and aerobic performance, while an increase in Hb (blood doping) causes an increase in VO2max and aerobic performance. If Hb is held constant, an increase in BV can cause and increase in both VO2max and aerobic performance, while a decrease in BV can cause a decrease in VO2max and aerobic performance. In addition, an increase in BV can compensate for moderate reductions in Hb through increase in Q, allowing VO2max to remain unchanged or even increase. Also, a large portion of the difference in the enhanced cardiovascular function of endurance athletes is due to their high BV and the resultant enhancement of diastolic function. Hence, optimizing both Hb and BV is a very important consideration for endurance performance.
Gledhill et al. (Mon,) conducted a review in Endurance performance. Hemoglobin and Blood Volume optimization was evaluated on VO2max and aerobic performance. Optimizing both hemoglobin concentration and blood volume enhances VO2max and aerobic performance, with increased blood volume compensating for moderate reductions in hemoglobin.