The Relationship between Power and Time to Fatigue in Cycle Ergometer Exercise

Abstract

The purpose of this study was to evaluate three critical power (P_critical) models. Ten university students performed tests that elicited fatigue in > 2 min to ∼ 10 min. Power and time data were fit to a 2-parameter hyperbolic model, a 3-parameter hyperbolic model, and a 3-parameter exponential model. Models described the power-time relationship well (R² ≥ 0.995). However, P_critical (209 ± 51 W; SEE: 20 ± 47 W) and the time constant (198 ± 87 s; SEE: 103 ± 246 W) from the exponential model have no obvious meaning. The 2-parameter model produced P_critical (187 ± 38 W) and anaerobic work capacity (20.4 ± 9.0 kJ) that have known physiological meaning, with excellent confidence (SEE: 2 ± 2 W and 1.0 ± 1.0 kJ, respectively). Addition of a maximal power parameter to the 2-parameter model did not improve description of the relationship, and the third parameter was superfluous. The 2-parameter model was preferred because, for the range of exercise durations used in this study, it describes the power-relationship adequately and in a most parsimonious fashion.

Aerobic - anaerobic - critical power - exercise - modeling

References

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