Effect of blood volume on plasma volume shift during exercise

To assess the relationship between blood volume (BV) and the reduction in plasma volume (PV) during exercise in individual variations, we measured BV and changes in PV in thirteen male volunteers during treadmill exercise until exhaustion. The lactate threshold (LT), as a predictor of aerobic exercise capacity, was calculated from the exercise intensity at the point of plasma lactate concentration buildup to 4 mmol. The relationship of peak VO₂ with BV indicated a significant positive correlation. The strong positive relation between the shifts in PV and total PV, and resulted in a maintenance of the circulating BV.