Altitude training and haemoglobin mass from the optimised carbon monoxide rebreathing method determined by a meta-analysis

Abstract

ObjectiveTo characterise the time course of changes in haemoglobin mass (Hbmass) in response to altitude exposure.MethodsThis meta-analysis uses raw data from 17 studies that used carbon monoxide rebreathing to determine Hbmass prealtitude, during altitude and postaltitude. Seven studies were classic altitude training, eight were live high train low (LHTL) and two mixed classic and LHTL. Separate linear-mixed models were fitted to the data from the 17 studies and the resultant estimates of the effects of altitude used in a random effects meta-analysis to obtain an overall estimate of the effect of altitude, with separate analyses during altitude and postaltitude. In addition, within-subject differences from the prealtitude phase for altitude participant and all the data on control participants were used to estimate the analytical SD. The ‘true’ between-subject response to altitude was estimated from the within-subject differences on altitude participants, between the prealtitude and during-altitude phases, together with the estimated analytical SD.ResultsDuring-altitude Hbmass was estimated to increase by ∼1.1%/100 h for LHTL and classic altitude. Postaltitude Hbmass was estimated to be 3.3% higher than prealtitude values for up to 20 days. The within-subject SD was constant at ∼2% for up to 7 days between observations, indicative of analytical error. A 95% prediction interval for the ‘true’ response of an athlete exposed to 300 h of altitude was estimated to be 1.1–6%.ConclusionsCamps as short as 2 weeks of classic and LHTL altitude will quite likely increase Hbmass and most athletes can expect benefit.

Rhodiola crenulata- and Cordyceps sinensis-Based Supplement Boosts Aerobic Exercise Performance after Short-Term High Altitude Training

“…The decline of ambient oxygen leading to tissue hypoxia, and this extreme physiological stress activates hypoxia-inducible factor 2 (HIF-2) and induces rapid EPO release from kidney (Wang and Semenza, 1996;Wojchowski et al, 2006;Socolovsky, 2007;Yeo et al, 2008;Castrop & Kurtz, 2010;Kapitsinou et al, 2010), indicating that high endogenous EPO level could serve as a stress indicator at altitude. Furthermore, previous studies have demonstrated that circulatory EPO level could markedly increase under physiological stress, such as performing exercise training at altitude of 1500-3000 m (Klausen et al, 1991;Chapman et al, 1998;Wolfarth, 2005;Gore et al, 2013). Similarly, here we also observed that serum EPO concentrations in subjects taking placebo was rapidly elevated and still remained at high levels when subjects returned to sea level after altitude training (*48% above pre-altitude training).…”

“…It is likely that a mediator other than total RBC number and oxygen consumption had a role in the further prolonged exhaustive run time by RC supplement after altitude training. Another possibility could be that potential effects of RC supplement on oxygen consumption were masked by high altitude exercise training in compared with the findings by Zhang et al (2009) at sea level, because high altitude training per se is an effective factor to markedly promote erythropoiesis and oxygen consumption (Gore et al, 2013).…”

Ventilatory Chemosensitivity, Cerebral and Muscle Oxygenation, and Total Hemoglobin Mass Before and After a 72-Day Mt. Everest Expedition

“…With prolonged moderate altitude (2300-3000 m) exposure a progressive increase of approximately 1.1% in tHb-mass for each 100 h of hypoxic exposure over 2 weeks of moderate altitude has been reported in a meta-analysis (Gore et al, 2013), with a proposed ceiling increase across multiple studies of approximately 7% after *500 h (Saunders et al, 2009). The actual measurement of tHb-mass before and following self-supported high-altitude climbing expeditions has not been previously reported.…”

The Effect of Training at 2100-m Altitude on Running Speed and Session Rating of Perceived Exertion at Different Intensities in Elite Middle-Distance Runners

“…[1][2][3][4][5] Training sessions completed in hypoxia evoke a higher physiological load than equivalent sessions completed in normoxia. 6 However, the reduced partial pressure of oxygen and subsequent re-duction in oxygen transport and uptake at race-like intensities [7][8][9] affects both performance and perceived exertion.…”