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

Area of Science:

• Exercise Physiology
• Sports Science
• Cardiovascular Adaptations

Background:

• Exercise training is known to induce physiological adaptations.
• Increases in plasma volume (hypervolemia) are a common response to training.
• The impact of training-induced hypervolemia on maximal aerobic power requires further clarification.

Purpose of the Study:

• To investigate the effect of training-induced plasma volume expansion on maximal aerobic power.
• To determine if hypervolemia influences oxygen consumption during sub-maximal and maximal exercise.
• To examine changes in cardiovascular and metabolic responses following short-term exercise training.

Main Methods:

• Eight male subjects (19-24 years) completed a 4-day training program at 71% maximal aerobic power.
• Plasma volume was measured using 131I-human serum albumin before and after training.
• Cardiovascular and metabolic parameters (oxygen consumption, heart rate, blood lactate) were assessed during sub-maximal and maximal exercise.

Main Results:

• Training significantly increased plasma volume (20.3%) and total blood volume (12.3%), with no change in red cell volume.
• Sub-maximal exercise showed unchanged oxygen consumption, ventilation, and blood lactate, but an elevated heart rate.
• Maximal exercise revealed increased carbon dioxide production, blood lactate, and peak power output, but not maximal aerobic power or ventilation.

Conclusions:

• Short-term exercise training induces hypervolemia without altering red cell volume.
• Hypervolemia does not appear to affect oxygen consumption during either sub-maximal or maximal exercise.
• While heart rate and peak power output increase, maximal aerobic power remains unaffected by training-induced hypervolemia.