Anaerobic energy provision does not limit Wingate exercise performance in endurance-trained cyclists.
J. A. Calbet, J. A. De Paz, N. Garatachea, S. Cabez de Vaca, J. Chavarren.
Journal Applied Physiology: 94, 668-676, 2003
Abstract
The aim of this study was to evaluate the effects of severe acute hypoxia on
exercise performance and metabolism during 30-s Wingate tests. Five endurance-
(E) and five sprint- (S) trained track cyclists from the Spanish National Team
performed 30-s Wingate tests in normoxia and hypoxia (inspired O(2) fraction =
0.10). Oxygen deficit was estimated from submaximal cycling economy tests by use
of a nonlinear model. E cyclists showed higher maximal O(2) uptake than S (72
+/- 1 and 62 +/- 2 ml x kg(-1) x min(-1), P < 0.05). S cyclists achieved higher
peak and mean power output, and 33% larger oxygen deficit than E (P < 0.05).
During the Wingate test in normoxia, S relied more on anaerobic energy sources
than E (P < 0.05); however, S showed a larger fatigue index in both conditions
(P < 0.05). Compared with normoxia, hypoxia lowered O(2) uptake by 16% in E and
S (P < 0.05). Peak power output, fatigue index, and exercise femoral vein blood
lactate concentration were not altered by hypoxia in any group. Endurance
cyclists, unlike S, maintained their mean power output in hypoxia by increasing
their anaerobic energy production, as shown by 7% greater oxygen deficit and 11%
higher postexercise lactate concentration. In conclusion, performance during
30-s Wingate tests in severe acute hypoxia is maintained or barely reduced owing
to the enhancement of the anaerobic energy release. The effect of severe acute
hypoxia on supramaximal exercise performance depends on training background.