Reduced running performance and greater perceived exertion, but similar post-exercise neuromuscular fatigue in tropical natives subjected to a 10 km self-paced run in a hot compared to a temperate environment

Jefferson F C Rodrigues Júnior; Thiago T Mendes; Patrícia F Gomes; Emerson Silami-Garcia; Fabiano T Amorim; Mário N O Sevilio Jr; Fabrício E Rossi; Samuel P Wanner

doi:10.1371/journal.pone.0290081

Reduced running performance and greater perceived exertion, but similar post-exercise neuromuscular fatigue in tropical natives subjected to a 10 km self-paced run in a hot compared to a temperate environment

PLoS One. 2023 Aug 17;18(8):e0290081. doi: 10.1371/journal.pone.0290081. eCollection 2023.

Authors

Jefferson F C Rodrigues Júnior¹, Thiago T Mendes², Patrícia F Gomes¹, Emerson Silami-Garcia^{1

3}, Fabiano T Amorim⁴, Mário N O Sevilio Jr⁵, Fabrício E Rossi^{6

7}, Samuel P Wanner¹

Affiliations

¹ Exercise Physiology Laboratory, School of Physical Education, Physiotherapy and Occupational Therapy, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
² Department of Physical Education, Faculty of Education, Universidade Federal da Bahia, Salvador, Bahia, Brazil.
³ Department of Sports, School of Physical Education, Physiotherapy and Occupational Therapy, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
⁴ Department of Health, Exercise and Sports Sciences, University of New Mexico, Albuquerque, New Mexico, United States of America.
⁵ Health Sciences Center, Universidade Federal do Maranhão, São Luís, Maranhão, Brazil.
⁶ Immunometabolism of Skeletal Muscle and Exercise Research Group and Laboratory of Muscle Performance, Department of Physical Education, Universidade Federal do Piauí, Teresina, Piauí, Brazil.
⁷ Graduate Program in Science and Health, Universidade Federal do Piauí, Teresina, Piauí, Brazil.

Abstract

Environmental heat stress impairs endurance performance by enhancing exercise-induced physiological and perceptual responses. However, the time course of these responses during self-paced running, particularly when comparing hot and temperate conditions, still needs further clarification. Moreover, monitoring fatigue induced by exercise is paramount to prescribing training and recovery adequately, but investigations on the effects of a hot environment on post-exercise neuromuscular fatigue are scarce. This study compared the time course of physiological and perceptual responses during a 10 km self-paced treadmill run (as fast as possible) between temperate (25°C) and hot (35°C) conditions. We also investigated the changes in countermovement jump (CMJ) performance following exercise in these two ambient temperatures. Thirteen recreational long-distance runners (11 men and 2 women), inhabitants of a tropical region, completed the two experimental trials in a randomized order. Compared to 25°C, participants had transiently higher body core temperature (TCORE) and consistently greater perceived exertion while running at 35°C (p < 0.05). These changes were associated with a slower pace, evidenced by an additional 14 ± 5 min (mean ± SD) to complete the 10 km at 35°C than at 25°C (p < 0.05). Before, immediately after, and 1 h after the self-paced run, the participants performed CMJs to evaluate lower limb neuromuscular fatigue. CMJ height was reduced by 7.0% (2.3 ± 2.4 cm) at 1 h after the race (p < 0.05) compared to pre-exercise values; environmental conditions did not influence this reduction. In conclusion, despite the reduced endurance performance, higher perceived exertion, and transiently augmented TCORE caused by environmental heat stress, post-exercise neuromuscular fatigue is similar between temperate and hot conditions. This finding suggests that the higher external load (faster speed) at 25°C compensates for the effects of more significant perceptual responses at 35°C in inducing neuromuscular fatigue.

Copyright: © 2023 Rodrigues Júnior et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Environment
Exercise
Female
Humans
Male
Muscle Fatigue*
Physical Exertion
Running*

Grants and funding

This study was financed by the Conselho Nacional de Desenvolvimento Científico e Tecnologico (CNPq/Brazil; www.gov.br/cnpq/; grant number: 427095/2018-2). This study was also supported by CNPq/MCTIC/CAPES/FNDCT/PROANTAR (grant number 442645/2018-0). In addition, SPW receives a fellowship from the CNPq for being a productive researcher (grant number: 315199/2021-0). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.