Time Trial Performance Is Sensitive to Low-Volume Autologous Blood Transfusion

Purpose This study tested the hypothesis that autologous blood transfusion (ABT) of similar to 50% of the red blood cells (RBC) from a standard 450-mL phlebotomy would increase mean power in a cycling time trial. In addition, the study investigated whether further ABT of RBC obtained from another 450-mL phlebotomy would increase repeated cycling sprint ability. Methods In a randomized, double-blind, placebo-controlled crossover design (3-month wash-out), nine highly trained male subjects donated two 450-mL blood bags each (BT trial) or were sham phlebotomized (PLA trial). Four weeks later, a 650-kcal time trial (n = 7) was performed 3 d before and 2 h after receiving either similar to 50% (135 mL) of the RBC or a sham transfusion. On the following day, transfusion of RBC (235 mL) from the second donation or sham transfusion was completed. A 4 x 30-s all-out cycling sprint interspersed by 4 min of recovery was performed 6 d before and 3 d after the second ABT (n = 9). Results The mean power was increased in time trials from before to after transfusion (P < 0.05) in BT (213 +/- 35 vs 223 +/- 38 W; mean +/- SD) but not in PLA (223 +/- 42 vs 224 +/- 46 W). In contrast, the mean power output across the four 30-s sprint bouts remained similar in BT (639 +/- 35 vs 644 +/- 26 W) and PLA (638 +/- 43 vs 639 +/- 25 W). Conclusions ABT of only similar to 135 mL of RBC is sufficient to increase mean power in a 650-kcal cycling time trial by similar to 5% in highly trained men. In contrast, a combined high-volume transfusion of similar to 135 and similar to 235 mL of RBC does not alter 4 x 30-s all-out cycling performance interspersed with 4 min of recovery.