Time course of haemoglobin mass during 21 days live high: train low simulated altitude

The aim of this study was to determine the time course of changes in haemoglobin mass (Hb_mass) in well-trained cyclists in response to live high:train low (LHTL). Twelve well-trained male cyclists participated in a 3-week LHTL protocol comprising 3,000 m simulated altitude for ∼14 h/day. Prior to LHTL duplicate baseline measurements were made of Hb_mass, maximal oxygen consumption (VO_2max) and serum erythropoietin (sEPO). Hb_mass was measured weekly during LHTL and twice in the week thereafter. There was a 3.3% increase in Hb_mass and no change in VO_2max after LHTL. The mean Hb_mass increased at a rate of ∼1% per week and this was maintained in the week after cessation of LHTL. The sEPO concentration peaked after two nights of LHTL but there was only a trivial correlation (r = 0.04, P = 0.89) between the increase in sEPO and the increase in Hb_mass. Athletes seeking to gain erythropoietic benefits from moderate altitude need to spend >12 h/day in hypoxia.