Effect of protocol on peak power output in continuous incremental cycle exercise tests.

Purpose: Peak power output ( W ˙ peak) in an incremental exercise test (EXT) is considered an important predictor of performance for cyclists. However, W ˙ peak is protocol dependent. The purpose of this study was to model the effect of EXT design on W ˙ peak. Methods: An adapted version of a previously developed mathematical model was used. For the purpose of validity testing, we compared predicted W ˙ peak differences (predicted Δ W ˙ peak) with actual Δ W ˙ peak found in sports science literature. Results: The model quantified Δ W ˙ peak between 36 EXT designs with stage durations in the range 1–5 min and increments in the range 10–50 W. Predicted Δ W ˙ peak and actual Δ W ˙ peak across a wide range of performance levels of cyclists were in good agreement. Depending on the specific combination of increment and stage duration, W ˙ peak may be widely different or equivalent. A minimum difference in increment (5 W) or in stage duration (1 min) already results in significantly different W ˙ peak. In EXTs having the same ratio between increment and stage duration, W ˙ peak in the EXT with the shortest stage duration or the greatest increment is significantly higher. Tests combining 15 W, 25 W or 40 W increments with 2, 3 and 4 min stage durations, respectively, are 'special' in that their W ˙ peak approximates the power output associated with maximal oxygen uptake ( P - V ˙ O 2 max ). Conclusions: The modeling results allow comparison of W ˙ peak between widely different EXT designs. Absolute performance level does not affect Δ W ˙ peak. W ˙ peak15/2, W ˙ peak25/3 and W ˙ peak40/4 constitute a practical physiologic reference for performance diagnostics and exercise intensity prescription. [ABSTRACT FROM AUTHOR]