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

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

doi:10.3390/ijerph18179193

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 (VO2max), and first and second ventilatory thresholds (VT1 and VT2, respectively) against the power output (wVO2max, 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, wVO2max, 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.

Highlights

Numerous major sports events, such as the Summer Olympic Games, world cups, and world championships are held in hot summer months
Critical power (CP) or critical velocity (CV) represents the upper limit of work rate or running speed that can be maintained at a metabolic steady state, and demarcates the heavy from severe exercise intensity domains [8]
This study examined the acute effects of high temperature (HT) on the physiological responses and exercise performance during 3-min all-out test (3MT) and incremental exercise tests (IETs)

Summary

Introduction

Numerous major sports events, such as the Summer Olympic Games, world cups, and world championships are held in hot summer months. Athletes in a high temperature (HT) environment must cope with external heat stress, which increases their level of fatigue and expedites exhaustion. Determining how athletes can train and compete effectively in HT environments is crucial. Acute heat stress impairs aerobic capacity and endurance performance, and elevated cardiovascular strain has long been considered as an important contributor [1,2,3,4,5,6,7]. Studies have used a single 3-min all-out test (3MT) as an alternative approach for determining CP, which is referred to as end-test power (EP) [9]. Previous studies have indicated that 3MT has a good test–retest reliability [10,11] and is a valid protocol for estimation of CP or CV [12,13]

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Discussion

Conclusion