Centre for Human Performance, Exercise and Rehabilitation, College of Health and Life Sciences, Brunel University London, Uxbridge, UK.
Division of Sport, Health and Exercise Sciences, Department of Life Sciences, College of Health and Life Sciences, Brunel University London, Uxbridge, UK.
Eur J Appl Physiol. 2019 Mar;119(3):653-664. doi: 10.1007/s00421-018-4055-0. Epub 2018 Dec 22.
Cooling sensations elicited by mouth rinsing with L-menthol have been reported as ergogenic. Presently, responses to L-menthol mouth rinsing during intermittent sprint performance (ISP) in the heat are unknown and the impact of increased thermal perception on ISP via capsaicin has also not been quantified. This experiment aimed to identify whether eliciting cooling/warming sensations via L-menthol/capsaicin would alter ISP in the heat.
Fourteen participants (mass = 72 ± 9 kg, [Formula: see text] = 3.30 ± 0.90 L min), undertook four experimental trials, involving 40 min of ISP in hot conditions (40.2 ± 0.6 °C, 42 ± 2% R.H.) with mouth rinsing (25 mL, 6 s) at the protocol onset, and every 10 min thereafter. Cooling (0.01% L-menthol; MEN), warming (0.2% capsaicin; CAP), placebo (0.3 sham-CHO; PLA), and control (water; CON) mouth rinses were utilized. Performance was quantified via power (PP) and work done (WD) during sprints. Heart rate (HR), core (T) and skin (T) temperature, perceived exertion (RPE), thermal sensation (T), and comfort (T) were measured at 10 min intervals. Sweat rate (whole-body sweat rate) was calculated from ∆mass.
PP reduced over time (P < 0.05); however, no change was observed between trials for PP or WD (P > 0.05). T increased over time and was lower in MEN (2.7 ± 1.1; P < 0.05) with no difference between CAP (3.1 ± 1.2), PLA (3.2 ± 1.3) and CON (3.1 ± 1.3). RPE, T HR, T, and T increased over time (P < 0.05) with no between trial differences (P > 0.05).
Despite improved thermal comfort via L-menthol, ISP did not improve. Capsaicin did not alter thermal perception or ISP. The reduction in ISP over time in hot conditions is not influenced by thermal perception.
用 L-薄荷醇漱口会引起凉爽的感觉，这已被证明具有增强体力的作用。目前，在热环境下进行间歇性冲刺表现（ISP）时，人们对 L-薄荷醇漱口的反应尚不清楚，并且通过辣椒素增加热感觉对 ISP 的影响也尚未量化。本实验旨在确定通过 L-薄荷醇/辣椒素引起凉爽/温暖感觉是否会改变热环境下的 ISP。
14 名参与者（体重=72±9kg，[公式：见文本]=3.30±0.90L/min）进行了四项实验，在热条件下（40.2±0.6°C，42±2%RH）进行 40 分钟 ISP，在方案开始时以及此后每 10 分钟用口漱（25mL，6s）。使用冷却（0.01% L-薄荷醇；MEN）、加热（0.2% 辣椒素；CAP）、安慰剂（0.3 假 CHO；PLA）和对照（水；CON）漱口液。通过冲刺期间的功率（PP）和做功（WD）来定量评估性能。心率（HR）、核心（T）和皮肤（T）温度、感知用力（RPE）、热感觉（T）和舒适度（T）每 10 分钟测量一次。通过 ∆mass 计算全身出汗率。
PP 随时间减少（P<0.05）；然而，PP 或 WD 之间的试验没有变化（P>0.05）。T 随时间增加，MEN 较低（2.7±1.1；P<0.05），CAP（3.1±1.2）、PLA（3.2±1.3）和 CON（3.1±1.3）之间没有差异。RPE、T HR、T、T 随时间增加（P<0.05），试验之间没有差异（P>0.05）。
尽管 L-薄荷醇改善了热舒适度，但 ISP 并没有提高。辣椒素没有改变热感觉或 ISP。在热条件下，随着时间的推移，ISP 的减少与热感觉无关。
