Proceedings of The Physiological Society
University of Oxford (2011) Proc Physiol Soc 23, PC214
Changes in erythropoietin concentration induced by acute hypoxia do not predict acute hypoxic ventilatory response or performance changes following living high - training low
J. V. Brugniaux1,2, P. Robach2,3, L. Schmitt2,4, F. Lasne5, J. Richalet2
1. Neurovascular Research Laboratory, Faculty of Health, Science & Sport, University of Glamorgan, Pontypridd, United Kingdom. 2. Laboratoire "R
Background and hypothesis: Upon exposure to hypoxia a series of adaptative responses are triggered to try to compensate the decrease in inspired PO2. For instance, minute ventilation increases within minutes of exposure (Powell et al., 1998) and increased circulating erythropoietin (Epo) concentration has been detected after durations as short as ≈84min (Eckardt et al., 1989). Recent research has highlighted a possible link between these two parameters (Brugniaux et al., in the press). On the another hand, intermittent hypoxic training protocols using living high - training (LHTL) have been demonstrated to improve performance notably through an increased oxygen carrying capacity following accelerated erythropoiesis (Brugniaux et al., 2006). It is, however, noticeable that certain athletes respond better than others (Chapman et al., 1998). Because of its involvement in both ventilatory acclimatization and erythropoiesis (and in turn aerobic performance), we hypothesised that the Epo response to an acute hypoxic exposure could predict the outcome of both of these adaptative responses. Methods: Thirty nine athletes (32 men, 7 women) out of 41 completed the entire study. These 39 athletes were exposed to a simulated altitude of 3,000m for 3h prior to a LHTL camp. On a separate day we also tested their acute hypoxic ventilatory response (HVR). Maximal aerobic performance was measured prior to and immediately after the LHTL camp. Results: Epo increased by 29.4 ± 28.2% [-20.5% - +105.7%] (P<0.001) following the acute exposure. There was no gender-difference in the increased Epo concentration (P=0.94). However, no correlation between Epo and either HVR or the changes in performance was observed. Conclusion: We conclude that despite the tight relation between oxygen sensing and Epo secretion, the time-domain difference of the respective response precludes any clear relation between these parameters. Moreover, despite its clear role in the increase in performance following LHTL, Epo is not the sole factor of the equation. This likely explains why Epo response to acute hypoxia could not be used to predict the outcome of LHTL and ultimately tease out potential “good responders” from “bad responders”.
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