Premium
A comparison of males and females' temporal patterning to short‐ and long‐term heat acclimation
Author(s) -
Mee J. A.,
Gibson O. R.,
Doust J.,
Maxwell N. S.
Publication year - 2015
Publication title -
scandinavian journal of medicine and science in sports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.575
H-Index - 115
eISSN - 1600-0838
pISSN - 0905-7188
DOI - 10.1111/sms.12417
Subject(s) - acclimatization , zoology , thermoregulation , heart rate , rectal temperature , medicine , biology , endocrinology , ecology , blood pressure
The current study assessed sex differences in thermoregulatory and physiological adaptation to short‐term ( STHA ) and long‐term heat acclimation ( LTHA ). Sixteen (eight males; eight females) participants performed three running heat tolerance tests ( RHTT ), preceding HA ( RHTT1 ), following 5 days HA ( RHTT2 ) and 10 days HA ( RHTT3 ). The RHTT involved 30‐min running (9 km/h, 2% gradient) in 40 °C, 40% relative humidity. Following STHA , resting rectal temperature ( Tr rest ) (males: −0.24 ± 0.16 °C, P ≤ 0.001; females: −0.02 ± 0.08 °C, P = 0.597), peak rectal temperature ( Tr peak ) (males: −0.39 ± 0.36 °C, P ≤ 0.001; females −0.07 ± 0.18 °C, P = 0.504), and peak heart rate (males: −14 ± 12 beats/min, P ≤ 0.001; females: −5 ± 3 beats/min, P = 0.164) reduced in males, but not females. Following STHA , sweat rate relative to body surface area ( SR BSA ) increased (428 ± 269 g/h/m 2 , P = 0.029) in females, but not males (−11 ± 286 g/h/m 2 , P = 0.029). Following LTHA , Tr rest (males: −0.04 ± 0.15 °C, P = 0.459; females: −0.22 ± 0.12 °C, P ≤ 0.01) and Tr peak (males: −0.05 ± 0.26 °C, P = 0.590; females: −0.41 ± 0.24 °C, P ≤ 0.01) reduced in females, but not males. Following LTHA , SR BSA increased in males (308 ± 346 g/h/m 2 , P = 0.029), but not females (44 ± 373 g/h/m 2 , P = 0.733). Males and females responded to STHA ; however, females required LTHA to establish thermoregulatory and cardiovascular stability. HA protocols should be designed to target sex differences in thermoregulation for optimal adaptation.