Do older firefighters show long-term adaptations to work in the heat?

Par Conseil national de recherches du Canada

DOI	Trouver le DOI : https://doi.org/10.1080/15459624.2013.821574
Auteur	Rechercher : Wright, Heather E.; Rechercher : Larose, Joanie; Rechercher : Mclellan, Tom M.; Rechercher : Miller, Scott; Rechercher : Boulay, Pierre; Rechercher : Kenny, Glen P.
Format	Texte, Article
Sujet	core temperature; physiological strain; perceptual strain; dry and humid heat; repeated heat stress
Résumé	Older experienced firefighters may show signs of heat adaptation, and thus reduced physiological strain, due to repeated occupational heat stress exposure. The aim was to examine physiological and perceptual strain, and hydration, responses to intermittent exercise in the heat in 12 older Non-Firefighter (Non-FF) and experienced Firefighter (FF) males, pair matched for age (Group mean ± SE: Non-FF = 51.7 ± 1.5, FF = 49.8 ± 1.1 years), VO(2peak) (Non-FF = 39.4 ± 2.2, FF = 40.7 ± 1.8 mL·kg(-1)·min(-1)), body surface area (Non-FF = 1.94 ± 0.04, FF = 2.03 ± 0.03 m(2)), and percent body fat (Non-FF = 24.4 ± 2.3, FF = 19.3 ± 1.8%). Rectal (Tre) and mean skin (MT(sk)) temperatures, heart rate (HR), local sweat rate (LSR), hydration indices, and ratings of thermal sensation and perceived exertion were measured during 4 ×15-min (rest 15-min) moderate-to-heavy cycling bouts (400 W heat production) in Dry and Humid heat (35°C, ∼20 and ∼60% relative humidity, respectively). No differences were observed between the Non-FF and FF for T(re), T(re) change, MT(sk), HR,% max HR, LSR, physiological strain index (PhSI), or % plasma volume change. Plasma protein concentration was reduced at baseline for the Non-FF (7.6 ± 0.1 g·100 mL(-1)) than FF (8.0 ± 0.1 g·100 mL(-1)). The Perceptual Strain Index overestimated PhSI for Non-FF and FF in both thermal conditions. At the end of exercise, the Non-FF showed a greater Tre difference between thermal conditions (0.27 ± 0.05°C) compared to the FF (0.10 ± 0.09°C). Although the Non-Firefighters and Firefighters demonstrate similar cardiovascular and hydration responses during moderate-to-heavy intensity exercise within each of the thermal conditions, the attenuated thermal effects between the two heat stress conditions in the Firefighters suggests a protective adaptation.
Date de publication	2013-12-01
Maison d’édition	Taylor and Francis
Dans	Journal of Occupational and Environmental Hygiene 10, nº 12 : 705–715.
Langue	anglais
Publications évaluées par des pairs	Oui
Publication du CNRC	Cette publication n’est pas du CNRC Ce sont des publications qui ont été rédigées par un auteur du CNRC, mais avant que celui-ci soit employé du CNRC.
Numéro NPARC	23001209
Exporter la notice	Exporter en format RIS
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Identificateur de l’enregistrement	afbf2017-dbb6-4d53-83e8-f4bf90133860
Enregistrement créé	2017-01-05
Enregistrement modifié	2020-04-22

Date de modification :: 2024-09-10