Increases in V?O2max with 'live high-train low' altitude training: Role of ventilatory acclimatization

摘要

The purpose of this study was to estimate the percentage of the increase in whole body maximal oxygen consumption (V? O2max) that is accounted for by increased respiratory muscle oxygen uptake after altitude training. Six elite male distance runners (V? O2max = 70.6 ± 4.5 ml kg-1 min-1) and one elite female distance runner (V? O2max = 64.7 ml kg-1 min-1) completed a 28-day "live high-train low" training intervention (living elevation, 2,150 m). Before and after altitude training, subjects ran at three submaximal speeds, and during a separate session, performed a graded exercise test to exhaustion. A regression equation derived from published data was used to estimate respiratory muscle V? O2 (V? O2RM) using our ventilation (V? E) values. V? O2RM was also estimated retrospectively from a larger group of distance runners (n = 22). V? O2max significantly (p 0.05) increased from pre- to post-altitude (196 ± 59 ml min-1), while V? E at V? O2max also significantly (p 0.05) increased (13.3 ± 5.3 l min-1). The estimated V? O2RM contributed 37 % of Δ V? O2max. The retrospective group also saw a significant increase in V? O2max from pre- to post-altitude (201 ± 36 ml min-1), along with a 10.8 ± 2.1 l min-1 increase in V? E, thus requiring an estimated 27 % of Δ V? O2max. Our data suggest that a substantial portion of the improvement in V? O2max with chronic altitude training goes to fuel the respiratory muscles as opposed to the musculature which directly contributes to locomotion. Consequently, the time-course of decay in ventilatory acclimatization following return to sea-level may have an impact on competitive performance.