Do older females store more heat than younger females during exercise in the heat?

Par Conseil national de recherches du Canada

DOI	Trouver le DOI : https://doi.org/10.1249/MSS.0b013e31829d24cc
Auteur	Rechercher : Larose, Joanie; Rechercher : Wright, Heather E.; Rechercher : Sigal, Ronald J.; Rechercher : Boulay, Pierre; Rechercher : Hardcastle, Stephen; Rechercher : Kenny, Glen P.
Format	Texte, Article
Sujet	aging, heat stress; thermoregulation; skin blood flow; sweating; calorimetry
Résumé	Introduction: Aging is associated with a reduction in the body’s capacity to dissipate heat. To date, few studies have examined age-related changes in thermoregulatory function during short exercise periods in the heat in older females. Purpose: This study aimed to investigate the effects of age on whole-body heat loss during intermittent exercise in the heat in young and older females. Methods: Direct and indirect calorimetry was used to measure whole-body evaporative heat loss (EHL), change in body heat content, and metabolic heat production. Eleven young (Y) (mean T SD age = 24 T 4 yr) and 13 older (O) (51 T 8 yr) females matched for body surface area (Y, 1.72 T 0.15; O, 1.75 T 0.12 m2) and fitness (V˙ O2max) (Y, 36.7 T 6.8 mL O2Ikgj1Iminj1; O, 33.8 T 8.0 mL O2Ikgj1Iminj1) performed four bouts of 15-min cycling (Ex1, Ex2, Ex3, and Ex4) at a constant rate of heat production (300 W) at 35-C and 20% relative humidity. Each exercise bout was separated by 15 min of rest. Results: EHL was reduced in O compared with Y during Ex1 (O, 199 T6 W; Y, 240 T9 W; P = 0.001), Ex2 (O, 238 T4 W; Y, 261 T 9 W, P = 0.023), and Ex3 (O, 249 T 4 W; Y, 274 T 11 W; P = 0.040). EHL was not different between groups during Ex4 or during the recovery periods. Older females had a greater change in body heat content compared with young females (O, 270 T 20 kJ; Y, 166 T 20 kJ; P = 0.001). Conclusion: These findings suggest that older females have a lower capacity for whole-body EHL compared with younger females during short intermittent exercise in the heat performed at a fixed rate of metabolic heat production
Date de publication	2013-12-01
Maison d’édition	American College of Sports Medicine
Dans	Medicine & Science in Sports & Exercise 45, nº 12 : 2265–2276.
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	23001216
Exporter la notice	Exporter en format RIS
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Identificateur de l’enregistrement	98adfd51-bfa3-4ebd-91ff-f35eb0163312
Enregistrement créé	2017-01-05
Enregistrement modifié	2020-04-22

Date de modification :: 2024-12-26