Prediction of Critical Power and W' in Hypoxia: Application to Work-Balance Modelling.

Townsend, Nathan E.; Nichols, David S.; Skiba, Philip F.; Racinais, Sebastien; Périard, Julien D.

Purpose: Develop a prediction equation for critical power (CP) and work above CP (W') in hypoxia for use in the work-balance (W' BAL) model. Methods : Nine trained male cyclists completed cycling time trials (TT; 12, 7, and 3 min) to determine CP and W' at five altitudes (250, 1,250, 2,250, 3,250, and 4,250 m). Least squares regression was used to predict CP and W' at altitude. A high-intensity intermittent test (HIIT) was performed at 250 and 2,250 m. Actual and predicted CP and W' were used to compute W' during HIIT using differential (W' BALdiff) and integral (W' BALint) forms of the W' BAL model. Results : CP decreased at altitude (P 2 = 0.99). W' decreased at 4,250m only (P BAL at 2,250m (P = 0.24). W' BALdiff returned higher values than W' BALint throughout HIIT (P BALdiff was not different to 0 kJ at completion, at 250m (0.7 ± 2.0 kJ; P = 0.33) and 2,250m (-1.3 ± 3.5 kJ; P = 0.30). However, W' BALint was lower than 0 kJ at 250m (-0.9 ± 1.3 kJ; P = 0.058) and 2,250m (-2.8 ± 2.8 kJ; P = 0.02). Conclusion: The altitude prediction equations for CP and W' developed in this study are suitable for use with the W' BAL model in acute hypoxia. This enables the application of W'BAL modelling to training prescription and competition analysis at altitude.

HYPOXEMIA; ISOTONIC regression; NUMERICAL analysis; HUMAN behavior; LOGICAL prediction

Frontiers in Physiology, 2017, Vol 8, p1

1664-042X

Academic Journal

10.3389/fphys.2017.00180