Modulation of neuromuscular excitability in response to acute noxious heat exposure has no additional effects on central and peripheral fatigability

Background: Whole-body hyperthermia (WBH) has an adverse effect on the nervous system and neurophysiological performance. In the present study, we examined whether short-duration whole-body immersion in 45°C water (HWI-45°C), which produces a strong neural and temperature flux without inducing WBH,...

Full description

Bibliographic Details
Main Authors: Nerijus Eimantas, Soneta Ivanove, Neringa Baranauskiene, Rima Solianik, Marius Brazaitis
Format: Article
Language:English
Published: Frontiers Media S.A. 2022-08-01
Series:Frontiers in Physiology
Subjects:
Online Access:https://www.frontiersin.org/articles/10.3389/fphys.2022.936885/full
_version_ 1811216577314422784
author Nerijus Eimantas
Soneta Ivanove
Neringa Baranauskiene
Rima Solianik
Marius Brazaitis
author_facet Nerijus Eimantas
Soneta Ivanove
Neringa Baranauskiene
Rima Solianik
Marius Brazaitis
author_sort Nerijus Eimantas
collection DOAJ
description Background: Whole-body hyperthermia (WBH) has an adverse effect on the nervous system and neurophysiological performance. In the present study, we examined whether short-duration whole-body immersion in 45°C water (HWI-45°C), which produces a strong neural and temperature flux without inducing WBH, can increase or impair neurophysiological performance in humans.Methods: Fifteen men (aged 25 ± 6 years) were enrolled in this study and participated in three experiments: 1) a brief (5-min) immersion of the whole body in 37°C water (WI-37°C); 2) a brief (5-min) HWI-45°C; and 3) a control trial in a thermoneutral condition at an ambient temperature of 24°C and 60% relative humidity. Before and after the immersions, neuromuscular function (electromyographic activity, reflexes, electrically and voluntary induced torque production, voluntary muscle activation level) were tested. To provoke central inhibition, the participants performed a sustained 2-min maximal voluntary contraction (MVC).Results: Thermophysiological strain was greater after HWI-45°C than after WI-37°C. Electrophysiological modulations of motor drive transmission and peripheral modulations of muscle contractility properties in response to HWI-45°C seemed to have little effect on central activation of the exercising muscles and no effect on MVC production.Conclusion: Although exposure to acute noxious heat was effective in evoking neuromuscular excitability, the increases in core temperature (∼0.2°C) and muscle temperature (∼0.6°C) did not induce moderate or severe WBH. These changes did not seem to affect central structures; that is, there were no additional increases in central and/or peripheral fatigue during a sustained 2-min MVC.
first_indexed 2024-04-12T06:41:30Z
format Article
id doaj.art-5bc59acb9e5744dcb8eb2410c06644d3
institution Directory Open Access Journal
issn 1664-042X
language English
last_indexed 2024-04-12T06:41:30Z
publishDate 2022-08-01
publisher Frontiers Media S.A.
record_format Article
series Frontiers in Physiology
spelling doaj.art-5bc59acb9e5744dcb8eb2410c06644d32022-12-22T03:43:42ZengFrontiers Media S.A.Frontiers in Physiology1664-042X2022-08-011310.3389/fphys.2022.936885936885Modulation of neuromuscular excitability in response to acute noxious heat exposure has no additional effects on central and peripheral fatigabilityNerijus EimantasSoneta IvanoveNeringa BaranauskieneRima SolianikMarius BrazaitisBackground: Whole-body hyperthermia (WBH) has an adverse effect on the nervous system and neurophysiological performance. In the present study, we examined whether short-duration whole-body immersion in 45°C water (HWI-45°C), which produces a strong neural and temperature flux without inducing WBH, can increase or impair neurophysiological performance in humans.Methods: Fifteen men (aged 25 ± 6 years) were enrolled in this study and participated in three experiments: 1) a brief (5-min) immersion of the whole body in 37°C water (WI-37°C); 2) a brief (5-min) HWI-45°C; and 3) a control trial in a thermoneutral condition at an ambient temperature of 24°C and 60% relative humidity. Before and after the immersions, neuromuscular function (electromyographic activity, reflexes, electrically and voluntary induced torque production, voluntary muscle activation level) were tested. To provoke central inhibition, the participants performed a sustained 2-min maximal voluntary contraction (MVC).Results: Thermophysiological strain was greater after HWI-45°C than after WI-37°C. Electrophysiological modulations of motor drive transmission and peripheral modulations of muscle contractility properties in response to HWI-45°C seemed to have little effect on central activation of the exercising muscles and no effect on MVC production.Conclusion: Although exposure to acute noxious heat was effective in evoking neuromuscular excitability, the increases in core temperature (∼0.2°C) and muscle temperature (∼0.6°C) did not induce moderate or severe WBH. These changes did not seem to affect central structures; that is, there were no additional increases in central and/or peripheral fatigue during a sustained 2-min MVC.https://www.frontiersin.org/articles/10.3389/fphys.2022.936885/fullmotor drivefatiguehyperthermiathermal therapythermal afferents
spellingShingle Nerijus Eimantas
Soneta Ivanove
Neringa Baranauskiene
Rima Solianik
Marius Brazaitis
Modulation of neuromuscular excitability in response to acute noxious heat exposure has no additional effects on central and peripheral fatigability
Frontiers in Physiology
motor drive
fatigue
hyperthermia
thermal therapy
thermal afferents
title Modulation of neuromuscular excitability in response to acute noxious heat exposure has no additional effects on central and peripheral fatigability
title_full Modulation of neuromuscular excitability in response to acute noxious heat exposure has no additional effects on central and peripheral fatigability
title_fullStr Modulation of neuromuscular excitability in response to acute noxious heat exposure has no additional effects on central and peripheral fatigability
title_full_unstemmed Modulation of neuromuscular excitability in response to acute noxious heat exposure has no additional effects on central and peripheral fatigability
title_short Modulation of neuromuscular excitability in response to acute noxious heat exposure has no additional effects on central and peripheral fatigability
title_sort modulation of neuromuscular excitability in response to acute noxious heat exposure has no additional effects on central and peripheral fatigability
topic motor drive
fatigue
hyperthermia
thermal therapy
thermal afferents
url https://www.frontiersin.org/articles/10.3389/fphys.2022.936885/full
work_keys_str_mv AT nerijuseimantas modulationofneuromuscularexcitabilityinresponsetoacutenoxiousheatexposurehasnoadditionaleffectsoncentralandperipheralfatigability
AT sonetaivanove modulationofneuromuscularexcitabilityinresponsetoacutenoxiousheatexposurehasnoadditionaleffectsoncentralandperipheralfatigability
AT neringabaranauskiene modulationofneuromuscularexcitabilityinresponsetoacutenoxiousheatexposurehasnoadditionaleffectsoncentralandperipheralfatigability
AT rimasolianik modulationofneuromuscularexcitabilityinresponsetoacutenoxiousheatexposurehasnoadditionaleffectsoncentralandperipheralfatigability
AT mariusbrazaitis modulationofneuromuscularexcitabilityinresponsetoacutenoxiousheatexposurehasnoadditionaleffectsoncentralandperipheralfatigability