Abstract

Introduction: A double-blind, randomised controlled trial examined the effect of a 450ml blood donation on exercise performance and, in particular, aimed to determine when performance returned to pre-donation levels. Methods: Maximal exercise in the form of a reliable, repeatable 20m multi level shuttle test was performed twice before and three times after venesection. Thirteen healthy young males completed the study protocol and were randomised; eight were venesected and five remained controls. The study was double blind. Results: One day following venesection, the bled group’s mean performance was reduced by 5.2% compared to controls (p=0.010) along with a drop of 7.7% in blood Hb concentration. At day eight, performance was still 4.9% below controls (p=0.017) with Hb concentration 5.4 % below baseline. At day twenty-two, performance was not significantly different from controls and Hb concentration was 1.7% below baseline. Psychological factors in the controls may cause the bled group’s performance drop to be underestimated. Conclusions: Blood donation significantly affects maximal exercise performance up to at least eight days after donation but returns to normal by twenty-two days. This information should allow athletes to plan donations around training and competition.