Int J Sports Med. 2003 Jan;24(1):9-14.
Influence of acute moderate hypoxia on time to exhaustion at vVO2max in unacclimatized runners.
Billat VL, Lepretre PM, Heubert RP, Koralsztein JP, Gazeau FP.
Laboratoire d’Etude de la Motricité Humaine, Faculté des Sciences du Sport, Université de Lille 2, Ronchin, France. veronique.billat@wanadoo.frCette adresse email est protégée contre les robots des spammeurs, vous devez activer Javascript pour la voir.
Eight unacclimatized long-distance runners performed, on a level treadmill, an incremental test to determine the maximal oxygen uptake (VO2max) and the minimal velocity eliciting VO2max (vVO2max) in normoxia (N) and acute moderate hypoxia (H) corresponding to an altitude of 2,400 m (PIO 2 of 109 mmHg). Afterwards, on separate days, they performed two all-out constant velocity runs at vO2 max in a random order (one in N and the other in H). The decrease in VO2max between N and H showed a great degree of variability amongst subjects as VO2max decreased by 8.9 +/- 4 ml x min(-1) x kg)(-1) in H vs. N conditions (-15.3 +/- 6.3 % with a range from -7.9 % to -23.8 %). This decrease in VO2max was proportional to the value of VO2max (VO2max vs. delta VO2max N-H, r = 0.75, p = 0.03). The time run at vVO2max was not affected by hypoxia (483 +/- 122 vs. 506 +/- 148 s, in N and H, respectively, p = 0.37). However, the greater the decrease in vVO2max during hypoxia, the greater the runners increased their time to exhaustion at vVO2max (vVO2max N-H vs. tlim @vVO2max N-H, r = -0.75, p = 0.03). In conclusion, this study showed that there was a positive association between the extent of decrease in vVO2max, and the increase in run time at vVO2max in hypoxia.
PMID: 12582946 [PubMed – indexed for MEDLINE]