The effect of blood infusion upon endurance capacity and ratings of perceived exertion.

The purpose of this investigation was to study the effect of blood infusion upon maximal endurance capacity and ratings of perceived exertaion (RPE). Sixteen long-distance runners, 13 of whom were marathoners, undertook four trials (T1-T4) of a treadmill run to exhaustion over a five week period. Criterion measures were time to exhaustion (TE) and RPE during each T. Data on Hb, Hct and RBCs were collected prior to each trial. Based on TE at T1, Ss were matched and assigned to either the experimental (E) or control (C) group. One week after T1, all Ss had 460 ml blood withdrawn. T2 was undertaken 2 weeks postwithdrawal. One week after T2, or 21 days postwithdrawal, the E group was infused with their own RBCs while the C group received 460 ml normal saline. T3 was taken 2 hours postinfusion and T4 one week later. The results of the factorial repeated measures ANOVA revealed no significant differences (p less than .05) between groups for either TE or RPE, even though the Hb level for the E group was significantly higher (P less than .01) than the C group at T3 and T4.