Training-induced hypervolemia: lack of an effect on oxygen utilization during exercise.

To investigate the effect of training-induced increases in plasma volume on maximal aerobic power, 8 male subjects (age 19 to 24 yr) underwent a 4-d training program (2 h X d-1) at an estimated 71% maximal aerobic power. Following training, plasma volume measured using 131I-human serum albumin increased by 20.3% (P less than 0.01) whereas red cell volume remained unchanged and total blood volume increased by 12.3% (P less than 0.01). During progressive sub-maximal cycle exercise, oxygen consumption, carbon dioxide production, ventilation, and blood lactate concentration remained unchanged following the training whereas heart rate was significantly elevated (P less than 0.05). Significant post-training elevations were also noted in carbon dioxide production (P less than 0.05), blood lactate (P less than 0.01), and peak power output (P less than 0.05) during maximal exercise. Maximal aerobic power and ventilation were not altered. It is concluded that hypervolemia induced by short-term exercise training does not affect oxygen consumption either during sub-maximal or maximal exercise.