Thermal Ergonomics Laboratory, Exercise and Sport Science, Faculty of Health Sciences, University of Sydney , Sydney, New South Wales , Australia.
School of Human Kinetics, University of Ottawa , Ottawa, Ontario , Canada.
Am J Physiol Regul Integr Comp Physiol. 2019 Jan 1;316(1):R13-R20. doi: 10.1152/ajpregu.00028.2018. Epub 2018 Nov 7.
This study sought to determine whether the temperature of water ingested before exercise alters the onset threshold and subsequent thermosensitivity of local vasomotor and sudomotor responses after exercise begins. Twenty men [24 (SD 4) yr of age, 75.8 (SD 8.1) kg body mass, 52.3 (SD 7.7) ml·min·kg peak O consumption (V̇o)] ingested 1.5°C, 37°C, or 50°C water (3.2 ml/kg), rested for 5 min, and then cycled at 50% V̇o for 15 min at 23.0 (SD 0.9) °C and 32 (SD 10) % relative humidity. Mean body temperature (T), local sweat rate (LSR), and skin blood flow (SBF) were measured. In a subset of eight men [25 (SD 5) yr of age, 78.6 (SD 8.3) kg body mass, 48.9 (SD 11.1) ml·min·kg V̇o], blood pressure was measured and cutaneous vascular conductance (CVC) was determined. The change in T was greater at the onset of LSR measurement with ingestion of 1.5°C than 50°C water [ΔT = 0.19 (SD 0.15) vs. 0.11 (SD 0.12) °C, P = 0.04], but not 37°C water [ΔT = 0.14 (SD 0.14) °C, P = 0.23], but did not differ between trials for SBF measurement [ΔT = 0.18 (SD 0.15) °C, 0.11 (SD 0.13) °C, and 0.09 (SD 0.09) °C with 1.5°C, 37°C, and 50°C water, respectively, P = 0.07]. Conversely, the thermosensitivity of LSR and SBF was not different [LSR = 1.11 (SD 0.75), 1.11 (SD 0.75), and 1.34 (SD 1.11) mg·min·cm·°C with 1.5°C, 37°C, and 50°C ingested water, respectively ( P = 0.46); SBF = 717 (SD 882), 517 (SD 606), and 857 (SD 904) %baseline arbitrary units (AU)/°C with 1.5°C, 37°C, and 50°C ingested water, respectively ( P = 0.95)]. After 15 min of exercise, LSR and SBF were greater with ingestion of 50°C than 1.5°C water [LSR = 0.40 (SD 0.17) vs. 0.31 (SD 0.19) mg·min·cm ( P = 0.02); SBF = 407 (SD 149) vs. 279 (SD 117) %baseline AU ( P < 0.001)], but not 37°C water [LSR = 0.50 (SD 0.22) mg·min·cm; SBF = 324 (SD 169) %baseline AU]. CVC was statistically unaffected [275 (SD 81), 340 (SD 114), and 384 (SD 160) %baseline CVC with 1.5°C, 37°C, and 50°C ingested water, respectively, P = 0.30]. Collectively, these results support the concept that visceral thermoreceptors modify the central drive for thermoeffector responses.
本研究旨在确定在运动开始前摄入的水温和运动开始后局部血管舒缩和出汗反应的热敏性之间是否存在关联。20 名男性[年龄 24（标准差 4）岁，体重 75.8（标准差 8.1）kg，峰值摄氧量（V̇o） 52.3（标准差 7.7）ml·min·kg]分别饮用 1.5°C、37°C 或 50°C 的水（3.2 ml/kg），休息 5 分钟，然后在 23.0（标准差 0.9）°C 和 32（标准差 10）%相对湿度下以 50%V̇o 骑行 15 分钟。测量平均体温（T）、局部出汗率（LSR）和皮肤血流（SBF）。在 8 名男性[年龄 25（标准差 5）岁，体重 78.6（标准差 8.3）kg，V̇o 48.9（标准差 11.1）ml·min·kg]的亚组中，测量血压并确定皮肤血管传导率（CVC）。与饮用 50°C 水相比，饮用 1.5°C 水时 LSR 测量的起始时体温变化更大[ΔT = 0.19（标准差 0.15）比 0.11（标准差 0.12）°C，P = 0.04]，但饮用 37°C 水时则不然[ΔT = 0.14（标准差 0.14）°C，P = 0.23]，但在 SBF 测量的试验之间没有差异[ΔT = 0.18（标准差 0.15）、0.11（标准差 0.13）和 0.09（标准差 0.09）°C，分别用 1.5°C、37°C 和 50°C 水，P = 0.07]。相反，LSR 和 SBF 的热敏性没有差异[LSR = 1.11（标准差 0.75）、1.11（标准差 0.75）和 1.34（标准差 1.11）mg·min·cm·°C，分别用 1.5°C、37°C 和 50°C 水摄入（P = 0.46）；SBF = 717（标准差 882）、517（标准差 606）和 857（标准差 904）%基线任意单位（AU）/°C，分别用 1.5°C、37°C 和 50°C 水摄入（P = 0.95）]。运动 15 分钟后，与饮用 1.5°C 水相比，饮用 50°C 水时 LSR 和 SBF 更高[LSR = 0.40（标准差 0.17）比 0.31（标准差 0.19）mg·min·cm（P = 0.02）；SBF = 407（标准差 149）比 279（标准差 117）%基线 AU（P < 0.001）]，但饮用 37°C 水则不然[LSR = 0.50（标准差 0.22）mg·min·cm；SBF = 324（标准差 169）%基线 AU]。CVC 在统计学上不受影响[分别用 1.5°C、37°C 和 50°C 水摄入时，CVC 为 275（标准差 81）、340（标准差 114）和 384（标准差 160）%基线 CVC，P = 0.30]。总的来说，这些结果支持内脏热敏感受器调节热敏效应器反应的中枢驱动力的概念。
