Haemoglobin mass and running time trial performance after recombinant human erythropoietin administration in trained men

Abstract

Recombinant human erythropoietin (rHuEpo) increases haemoglobin mass (Hb(mass)) and maximal oxygen uptake (v O(2 max)).

Purpose: This study defined the time course of changes in Hb(mass), v O(2 max) as well as running time trial performance following 4 weeks of rHuEpo administration to determine whether the laboratory observations would translate into actual improvements in running performance in the field.

Methods: 19 trained men received rHuEpo injections of 50 IU•kg(-1) body mass every two days for 4 weeks. Hb(mass) was determined weekly using the optimized carbon monoxide rebreathing method until 4 weeks after administration. v O(2 max) and 3,000 m time trial performance were measured pre, post administration and at the end of the study.

Results: Relative to baseline, running performance significantly improved by ∼6% after administration (10:30±1:07 min:sec vs. 11:08±1:15 min:sec, p<0.001) and remained significantly enhanced by ∼3% 4 weeks after administration (10:46±1:13 min:sec, p<0.001), while v O(2 max) was also significantly increased post administration (60.7±5.8 mL•min(-1)•kg(-1) vs. 56.0±6.2 mL•min(-1)•kg(-1), p<0.001) and remained significantly increased 4 weeks after rHuEpo (58.0±5.6 mL•min(-1)•kg(-1), p = 0.021). Hb(mass) was significantly increased at the end of administration compared to baseline (15.2±1.5 g•kg(-1) vs. 12.7±1.2 g•kg(-1), p<0.001). The rate of decrease in Hb(mass) toward baseline values post rHuEpo was similar to that of the increase during administration (-0.53 g•kg(-1)•wk(-1), 95% confidence interval (CI) (-0.68, -0.38) vs. 0.54 g•kg(-1•)wk(-1), CI (0.46, 0.63)) but Hb(mass) was still significantly elevated 4 weeks after administration compared to baseline (13.7±1.1 g•kg(-1), p<0.001).

Conclusion: Running performance was improved following 4 weeks of rHuEpo and remained elevated 4 weeks after administration compared to baseline. These field performance effects coincided with rHuEpo-induced elevated v O(2 max) and Hb(mass).

Figure 1. Individual changes in Hb_mass (A), red cell (B), plasma (C) and blood (D) volume.

Each line corresponds to one subject and each symbol corresponds to the same subject in all figures. Individual mean value was calculated when more than one blood sample was collected per week. The bar graphs represent the mean values of the 19 subjects. The grey bars represent the 4 weeks of rHuEpo administration.

Figure 2. Individual changes in carboxyhaemoglobin.

Each line corresponds to one subject. Individual mean value was calculated when more than one blood sample was collected per week. The bar graphs represent the mean values of the 19 subjects. The grey bars represent the 4 weeks of rHuEpo administration.