Differences between sexes in thermoregulatory responses and exercise time during endurance exercise in a hot environment following pre-cooling with ice slurry ingestion. (December 2020)

• Record Type: Journal Article
• Authors: Iwata, Risa; Kawamura, Takuji; Hosokawa, Yuri; Chang, Lili; Suzuki, Katsuhiko; Muraoka, Isao
• Is Part Of: Journal of thermal biology. Volume 94(2020)
• Publication Date: 2020-12
• Subjects: Sex differences -- Ice slurry -- Pre-cooling -- Thermoregulation -- Endurance exercise; ICE ice slurry trial -- CON control trial -- Tre rectal temperature -- Tsk skin temperature -- TS thermal sensation -- TC thermal comfort -- RPE rating of perceived exertion -- Tre-cool the magnitudes of decreasing rectal temperature during drinking -- WBSL whole body sweat loss -- M metabolic heat production -- USG urine specific gravity; Thermobiology -- Periodicals; Temperature -- Periodicals; Biology -- Periodicals; Thermobiologie -- Périodiques; Thermobiology; Periodicals; 571.46
• DOI: 10.1016/j.jtherbio.2020.102746
• Languages: English
• ISSNs: 0306-4565

Abstract

Abstract: This study aimed to examine differences between sexes in thermoregulatory responses and exercise time after ice slurry ingestion in a hot environment. Twenty-four healthy adults (male n = 12, body weight (BW) = 65.8 ± 10.3; female n = 12, BW = 58.2 ± 10.0) ingested 7.5 g/kg of either ice slurry at −1 °C (ICE) or control water at 20 °C (CON) before cycling at 55%VO2 max in a hot environment (controlled at 38 °C, 40% relative humidity). Rectal (Tre) and skin (Tsk) temperature, heart rate, sweat rate, respiratory gases, ratings of thermal sensation (TS), thermal comfort (TC), and rating of perceived exertion (RPE) were measured. Ice slurry did not improve exercise time in both sexes despite Tre was significantly lower in ICE than CON in both sexes. Tre, Tsk, HR, sweat rate and TS did not differ between sexes. TC and RPE in ICE were significantly higher during exercise in males than in females. In conclusion, there were no sex differences in the effects of pre-cooling with ice slurry ingestion; however, pre-cooling with ice slurry may be more effective in mitigating ratings of TC and RPE in females than males. Highlights: No sex differences were observed in the effect of ice slurry. Perceived measurements were different between sexes due to pre-cooling with ice slurry. Sweating did not differ between sexes during exercise at same relative intensity.