title: Cold drink attenuates heat strain during work-rest cycles.
abstract: There is limited information on the ingestion of cold drinks after exercise. We investigated the thermoregulatory effects of ingesting drinks at 4°C (COLD) or 28°C (WARM) during work-rest cycles in the heat. On 2 separate occasions, 8 healthy males walked on the treadmill for 2 cycles (45 min work; 15 min rest) at 5.5 km/h with 7.5% gradient. Two aliquots of 400 mL of plain water at either 4°C or 28°C were consumed during each rest period. Rectal temperature (T re ), skin temperature (T sk ), heart rate and subjective ratings were measured. Mean decrease in T re at the end of the final work-rest cycle was greater after the ingestion of COLD drinks (0.5±0.2°C) than WARM drinks (0.3±0.2°C; P<0.05). Rate of decrease in T sk was greater after ingestion of COLD drinks during the first rest period (P<0.01). Mean heart rate was lower after ingesting COLD drinks (P<0.05). Ratings of thermal sensation were lower during the second rest phase after ingestion of COLD drinks (P<0.05). The ingestion of COLD drinks after exercise resulted in a lesser than expected reduction of T re . Nevertheless, the reduction in T re implies a potential for improved work tolerance during military and occupational settings in the heat.
authors.affiliation: Department of Physiology, Yong Loo Lin School of Medicine, National -University of Singapore, Singapore.
authors.forename: J K W
authors.initials: JK
authors.lastname: Lee
authors.forename: Z W
authors.initials: ZW
authors.lastname: Yeo
authors.forename: A Q X
authors.initials: AQ
authors.lastname: Nio
authors.forename: A C H
authors.initials: AC
authors.lastname: Koh
authors.forename: Y S
authors.initials: YS
authors.lastname: Teo
authors.forename: L F
authors.initials: LF
authors.lastname: Goh
authors.forename: P M S
authors.initials: PM
authors.lastname: Tan
authors.forename: C
authors.initials: C
authors.lastname: Byrne
mesh_terms: D001831:Body Temperature; D003080:Cold Temperature; D004326:Drinking / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D017079:Exercise Tolerance / Q000502:physiology*; D006339:Heart Rate / Q000502:physiology*; D006358:Hot Temperature; D006801:Humans; D008297:Male; D012146:Rest; D012881:Skin Temperature; D055815:Young Adult