Determining Validity of Critical Power Estimated Using a Three-Minute All-Out Test in Hot Environments

Yu-Hsuan Kuo; Ching-Feng Cheng; Yu-Chi Kuo

doi:10.3390/ijerph18179193

Determining Validity of Critical Power Estimated Using a Three-Minute All-Out Test in Hot Environments

Int J Environ Res Public Health. 2021 Aug 31;18(17):9193. doi: 10.3390/ijerph18179193.

Authors

Yu-Hsuan Kuo¹, Ching-Feng Cheng^{2

3}, Yu-Chi Kuo⁴

Affiliations

¹ Department of Physical Education, Chinese Culture University, Taipei 11114, Taiwan.
² Department of Athletic Performance, National Taiwan Normal University, Taipei 11677, Taiwan.
³ Sports Performance Lab., National Taiwan Normal University, Taipei 11677, Taiwan.
⁴ Department of Exercise and Health Science, National Taipei University of Nursing and Health Sciences, Taipei 11219, Taiwan.

Abstract

The aim of this study was to investigate the effects of heat on the validity of end-test power (EP) derived from a 3-min all-out test (3MT), which is considered as an alternative method for determining the conventional critical power. Twelve male cyclists were required to perform incremental exercise tests (IET) and 3MTs in both high temperature (HT; 35 °C) and thermoneutral temperature (NT; 22 °C) environments. Maximal oxygen uptake (VO_2max), and first and second ventilatory thresholds (VT₁ and VT₂, respectively) against the power output (wVO_2max, wVT₁, and wVT₂) were measured during IETs. EP was recorded during the 3MTs. A significant correlation was observed between wVT₂ and EP under NT (r = 0.674, p < 0.05) and under HT (r = 0.672, p < 0.05). However, wVO_2max, wVT₁, wVT₂, and EP were significantly higher in NT than in HT (p < 0.05). In conclusion, although the physiological stress induced by HT might impair exercise performance, the EP derived from 3MT can validly estimate wVT₂ under HT conditions.

Keywords: critical threshold; exercise intensity; fitness test; heat.

MeSH terms

Bicycling
Exercise
Exercise Test*
Hot Temperature
Humans
Male
Oxygen Consumption*