Mild increases in haematocrit (Hct) have been shown to enhance aerobic performance, but the effects of more severe increases have not been studied. Recombinant human erythropoietin (rHuEPO), which can cause substantial increases in haematocrit, was used to study the effects of induced severe polycythemia on aerobic endurance performance. Sixteen Sprague-Dawley rats were aerobically trained on motorized running wheels. After 5 weeks, the baseline aerobic endurance of each animal was determined by measuring the running time to exhaustion (RTE). Then each rat was randomly assigned to an experimental group (EXP) which received 600 U kg-1 rHuEPO every 3 days, or a placebo group (PLC). Haematocrit and animal mass were monitored for 3 weeks while training and treatment continued, and then the RTE was determined a second time. Results indicated that the rats in the treatment group had a significantly higher Hct (62.2% vs. PLC value of 47.3%, p < 0.001), but did not have a different RTE (75 min vs. PLC value of 73 min, p > 0.05) when compared to the placebo group. The change in the Hct compared to the change in RTE for each animal showed an inverse relationship (r = -0.8212), indicating that greater increases in rHuEPO induced polycythemia resulted in a decreased performance level. We conclude that rHuEPO-induced severe polycythemia was not accompanied by an increase in aerobic endurance in this animal model.
View details for Web of Science ID A1994NC87100008
View details for PubMedID 8171272