Prediction of Exercise Tolerance in the Severe and Extreme Intensity Domains by a Critical Power Model

Thiago Pereira Ventura; Fernando Klitzke Borszcz; Diego Antunes; Fabrizio Caputo; Tiago Turnes

doi:10.5114/jhk/170101

Prediction of Exercise Tolerance in the Severe and Extreme Intensity Domains by a Critical Power Model

J Hum Kinet. 2023 Sep 5:89:113-122. doi: 10.5114/jhk/170101. eCollection 2023 Oct.

Authors

Thiago Pereira Ventura¹, Fernando Klitzke Borszcz¹, Diego Antunes¹, Fabrizio Caputo², Tiago Turnes¹

Affiliations

¹ Physical Effort Laboratory, Sports Center, Federal University of Santa Catarina, Florianopolis, Brazil.
² Human Performance Research Group, Center for Health Sciences and Sport, Santa Catarina State University, Florianopolis, Brazil.

Abstract

This study aimed to assess the predictive capability of different critical power (CP) models on cycling exercise tolerance in the severe- and extreme-intensity domains. Nineteen cyclists (age: 23.0 ± 2.7 y) performed several time-to-exhaustion tests (Tlim) to determine CP, finite work above CP (W'), and the highest constant work rate at which maximal oxygen consumption was attained (I_HIGH). Hyperbolic power-time, linear power-inverse of time, and work-time models with three predictive trials were used to determine CP and W'. Modeling with two predictive trials of the CP work-time model was also used to determine CP and W'. Actual exercise tolerance of I_HIGH and intensity 5% above I_HIGH (I_HIGH+5%) were compared to those predicted by all CP models. Actual I_HIGH (155 ± 30 s) and I_HIGH+5% (120 ± 26 s) performances were not different from those predicted by all models with three predictive trials. Modeling with two predictive trials overestimated Tlim at I_HIGH+5% (129 ± 33 s; p = 0.04). Bland-Altman plots of I_HIGH+5% presented significant heteroscedasticity by all CP predictions, but not for I_HIGH. Exercise tolerance in the severe and extreme domains can be predicted by CP derived from three predictive trials. However, this ability is impaired within the extreme domain.

Keywords: cycling; high-intensity exercise; maximal oxygen uptake; power-duration relationship.