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

Abstract

ObjectivesThe 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.MethodsHaemoglobin-oxygen saturation (Hb-sO2), arterial oxygen content (CaO2), haemoglobin mass (Hbmass), blood volume (BV) and blood gas concentrations were measured before descent (Bolivians only), together with aerobic fitness (via Yo-YoIR1), near sea-level, after ascent and during 13 days at 3600 m.ResultsAt baseline, haemoglobin concentration [Hb] and Hbmass 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; Hbmass was constant regardless of altitude. In Australians, [Hb] increased after 12 days at 3600 m to 17.3±1.0 g/dL; Hbmass increased by 3.0±2.7% (p≤0.01). BV decreased in both teams at altitude by ∼400 mL. Arterial partial pressure for oxygen (PaO2), Hb-sO2 and CaO2 of both teams decreased within 2 h of arrival at 3600 m (p≤0.001) but increased over the following days, with CaO2 overcompensated in Australians (+1.7±1.2 mL/100 mL; p≤0.001). Yo-YoIR1 was lower on the 3rd versus 10th day at altitude and was significantly related to CaO2.ConclusionsThe marked drop in PaO2 and CaO2 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 CaO2 (mostly due to loss of plasma volume), 12 days appears insufficient to reach chronic levels of adaption.

Wellness, fatigue and physical performance acclimatisation to a 2-week soccer camp at 3600 m (ISA3600)

“…While body composition data are lacking, this increase in the Bolivians was likely related to plasma volume expansion34 and the development of peripheral oedema 1. Conversely at altitude, both teams lost 0.2–0.3 kg/day during the first 5 days (figure 2), which is in agreement with previous data in young skiers during a 6-day training camp at 2830 m 35.…”

“…Although limited to only six players, these results confirm the generally reported aerobic-related performance rebound 1–2 weeks after descent from altitude 9. The exact physiological mechanisms of this improved high-intensity running capacity remain unclear, but the haematological changes reported34 should be considered. After the camp sprinting performance was further impaired; this impairment was four times greater than that earlier during the season (eg, March to April).…”

“…An acute elevation of HRex is common7 8 45 at altitude and its recovery is likely related to altitude severity 5 7. It is however worth noting that as with resting HRV, the acute changes observed in the Bolivians after returning to altitude were exacerbated, possibly due to their plasma volume expansion at near-sea-level 34. This hypothesis is confirmed by the fact that, in contrast to Yo-YoIR1 performance, HRex did not return to baseline values by the end of the camp in the Bolivians.…”

“…These results may reflect a limitation of HRV measures to accurately assess cardiac autonomic function in the present setting, at least in high-altitude native players examined near-sea-level. Since an increased blood volume decreases HR and increases HRV,38 the fluid alterations observed in the Bolivians34 could have triggered parasympathetic activity further than its actual resting level. This phenomenon should not be overlooked when using resting HR measures to estimate cardiac autonomic activity.…”

Update in the understanding of altitude-induced limitations to performance in team-sport athletes

“…Competition at high altitude (>3000 m) poses other challenges. However, there is evidence of incomplete acclimatisation in TS athletes after more than 2 weeks at altitude 69 70…”