Changes in blood gas transport of altitude native soccer players near sea-level and sea-level native soccer players at altitude (ISA3600)

摘要

Objectives The optimal strategy for soccer teams playing at altitude is not known, that is, 'fly-in, fly-out' versus short-term acclimatisation. Here, we document changes in blood gas and vascular volumes of sea-level (Australian, n=20) and altitude (Bolivian, n=19) native soccer players at 3600 m. Methods Haemoglobin-oxygen saturation (Hb-sO_2), arterial oxygen content (CaO_2), haemoglobin mass (Hb_(mass)), blood volume (BV) and blood gas concentrations were measured before descent (Bolivians only), together with aerobic fitness (via Yo-YolRI), near sea-level, after ascent and during 13 days at 3600 m. Results At baseline, haemoglobin concentration [Hb] and Hb_(mass) were higher in Bolivians (mean+-SD; 18.2 ±1.0 g/dL, 12.8+-0.8 g/kg) than Australians (15.0+-0.9 g/ dL, 11.6+-0.7 g/kg; both p<0.001). Near sea-level, [Hb] of Bolivians decreased to 16.6+-0.9 g/dL, but normalised upon return to 3600 m; Hb_(mass) was constant regardless of altitude. In Australians, [Hb] increased after 12 days at 3600 m to 17.3+-1.0 g/dL; Hb_(mass) increased by 3.0 ±2.7% (p<0.01). BV decreased in both teams at altitude by approx400 mL Arterial partial pressure for oxygen (PaO_2), Hb-sO_2 and CaO_2 of both teams decreased within 2 h of arrival at 3600 m (p<0.001) but increased over the following days, with CaO_2 ove-rcompensated in Australians (+1.7+-1.2 mL/100 mL; p<0.001). Yo-YolRI was lower on the 3rd versus 10th day at altitude and was significantly related to CaO_2. Conclusions The marked drop in PaO_2 and CaO_2 observed after ascent does not support the 'fly-in, fly-out' approach for soccer teams to play immediately after arrival at altitude. Although short-term acclimatisation was sufficient for Australians to stabilise their CaO_2 (mostly due to loss of plasma volume), 12 days appears insufficient to reach chronic levels of adaption.