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

Abstract

Purpose

Peak power output (${\dot{{\rm W}}}$peak) in an incremental exercise test (EXT) is considered an important predictor of performance for cyclists. However, ${\dot{{\rm W}}}$peak is protocol dependent. The purpose of this study was to model the effect of EXT design on ${\dot{{\rm W}}}$peak.

Methods

An adapted version of a previously developed mathematical model was used. For the purpose of validity testing, we compared predicted ${\dot{{\rm W}}}$peak differences (predicted Δ${\dot{{\rm W}}}$peak) with actual Δ${\dot{{\rm W}}}$peak found in sports science literature.

Results

The model quantified Δ${\dot{{\rm W}}}$peak between 36 EXT designs with stage durations in the range 1–5 min and increments in the range 10–50 W. Predicted Δ${\dot{{\rm W}}}$peak and actual Δ${\dot{{\rm W}}}$peak across a wide range of performance levels of cyclists were in good agreement. Depending on the specific combination of increment and stage duration, ${\dot{{\rm W}}}$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 ${\dot{{\rm W}}}$peak. In EXTs having the same ratio between increment and stage duration, ${\dot{{\rm W}}}$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 ${\dot{{\rm W}}}$peak approximates the power output associated with maximal oxygen uptake (${\text{P}}-{\dot{\text{V}}\text{O}}_{2} \max$).

Conclusions

The modeling results allow comparison of ${\dot{{\rm W}}}$peak between widely different EXT designs. Absolute performance level does not affect Δ${\dot{{\rm W}}}$peak. ${\dot{{\rm W}}}$peak15/2, ${\dot{{\rm W}}}$peak25/3 and ${\dot{{\rm W}}}$peak40/4 constitute a practical physiologic reference for performance diagnostics and exercise intensity prescription.