Sport Physiology Department, Sport Science and Medicine Centre, Singapore Sport Institute, 3 Stadium Drive, Singapore, 397630, Singapore.
Nanyang Technological University, National Institute of Education, 1 Nanyang Walk, Singapore, 637616, Singapore.
Eur J Appl Physiol. 2023 Oct;123(10):2225-2237. doi: 10.1007/s00421-023-05235-y. Epub 2023 May 31.
This study examined the thermoregulatory response and ergogenic effects of ice slurry (ICE) ingestion in hot environments with high and low relative humidity (RH).
Eight males completed four trials in a crossover manner in dry (DRY: 34.7 ± 0.2 °C, 38 ± 2%RH) and humid heat (HUM: 34.8 °C ± 0.2 °C, 80 ± 1%RH). They ingested 8.0 g·kg of ICE (0.0 °C) or 37.5 °C water (CON) during 30 min before exercise, and three aliquots (3.2 g·kg) of ICE or CON during 45-min cycling at 50%[Formula: see text]O, followed by cycling to exhaustion at 80%[Formula: see text]O (TTE). Body core temperature (T), mean skin temperature (T), heart rate (HR), thermal comfort, thermal sensation and rating of perceived exertion (RPE) were measured.
Relative to CON, ICE improved TTE by 76.5 ± 96.5% in HUM and 21.3 ± 44.9% in DRY (p = 0.044). End-exercise T was lower in ICE versus CON in DRY (37.8 ± 0.4 °C versus 38.1 ± 0.3 °C, p = 0.005) and HUM (38.8 ± 0.4 °C versus 39.3 ± 0.6 °C, p = 0.004). ICE decreased HR, heat storage and heat strain index only in DRY (p < 0.001-0.018). ICE improved thermal sensation and comfort in DRY and HUM (p < 0.001-0.011), attenuated RPE in HUM (p = 0.012) but not in DRY (p = 0.065).
ICE tended to benefit performance in humid heat more than in dry heat. This is likely due to the reduced extent of hyperthermia in dry heat and the relative importance of sensory inputs in mediating exercise capacity.
本研究旨在探讨在高、低相对湿度(RH)的热环境中,冰浆(ICE)摄入对体温调节反应和增效作用。
8 名男性以交叉方式完成了 4 项试验,分别在干燥(DRY:34.7±0.2°C,38±2%RH)和湿热(HUM:34.8°C±0.2°C,80±1%RH)环境下进行。他们在运动前 30 分钟内摄入 8.0g·kg 的 ICE(0.0°C)或 37.5°C 的水(CON),然后在 50%[Formula: see text]O 的 45 分钟自行车运动中摄入三个等分的 ICE 或 CON(3.2g·kg),随后以 80%[Formula: see text]O 的速度进行自行车运动直至力竭(TTE)。测量核心体温(T)、平均皮肤温度(T)、心率(HR)、热舒适度、热感觉和主观体力感觉(RPE)。
与 CON 相比,ICE 在 HUM 中使 TTE 提高了 76.5±96.5%,在 DRY 中提高了 21.3±44.9%(p=0.044)。在 DRY 中,ICE 摄入后 TTE 结束时的 T 低于 CON(37.8±0.4°C 与 38.1±0.3°C,p=0.005),在 HUM 中,TTE 结束时的 T 也低于 CON(38.8±0.4°C 与 39.3±0.6°C,p=0.004)。ICE 仅在 DRY 中降低了 HR、热量储存和热量应激指数(p<0.001-0.018)。ICE 提高了 DRY 和 HUM 中的热感觉和舒适度(p<0.001-0.011),降低了 HUM 中的 RPE(p=0.012),但在 DRY 中没有(p=0.065)。
ICE 似乎更有利于湿热环境中的运动表现,而不是干燥热环境中的运动表现。这可能是由于在干燥热环境中体温过高的程度较低,以及感觉输入在调节运动能力方面的相对重要性。