Carbohydrate mouth rinse reduces rating of perceived exertion but does not affect performance and energy systems contribution during a high-intensity exercise

ABSTRACT Aim The study aimed to verify the effect of carbohydrate (CHO) mouth rinse on time to exhaustion, energy systems contribution and rating of perceived exertion (RPE) during a high-intensity exercise. Methods Fourteen men performed an incremental exercise test to determine their maximal oxygen uptake and peak power output (PPO) and two time-to-exhaustion tests at 110% of PPO. Participants rinsed their mouth with 25ml of 6.4% of CHO or placebo (PLA) solution immediately before the time-to-exhaustion test, using a crossover design. The contribution of the energy systems was calculated using the free software GEDAE-LaB®. Results Time to exhaustion was similar between the conditions (CHO:174.3±42.8s; PLA:166.7±26.3s; p=0.33). In addition, there was no difference between the CHO and PLA condition for aerobic (CHO:135.1±41.2kJ and PLA:129.8±35.3kJ, p=0.34), anaerobic lactic (CHO:57.6±17.1kJ and PLA:53.4±15.1kJ, p=0.10), and anaerobic alactic (CHO:10.4±8.4kJ and PLA:13.2±9.2kJ, p=0.37) contribution. Consequently, total energy expenditure was similar between conditions (CHO:203.2±46.4kJ and PLA:196.5±45.2kJ, p=0.15). However, CHO mouth rinse reduced the RPE at the moment of exhaustion (CHO:18.2±1.0units and PLA:19.1±1.1units; p=0.02). Conclusion CHO mouth rinse neither increased time to exhaustion nor altered energy systems contribution during a high-intensity exercise, but reduced the perceived effort at the exhaustion.

摘要
目的 本研究旨在验证碳水化合物（carbohydrate, CHO）含漱对高强度运动过程中力竭时间、能量系统供能占比以及自觉用力程度分级（rating of perceived exertion, RPE）的影响。
方法 14名男性受试者先后完成递增负荷运动测试，以测定其最大摄氧量与最大功率输出（peak power output, PPO），并完成2次以110%PPO强度进行的力竭运动测试。在力竭测试开始前，受试者分别用25mL 6.4%的CHO溶液或安慰剂（placebo, PLA）溶液进行含漱，实验采用交叉设计。能量系统供能占比通过免费软件GEDAE-LaB®计算得出。
结果 两组受试者的力竭时间无显著差异（CHO组：174.3±42.8s；安慰剂组：166.7±26.3s；p=0.33）。此外，CHO组与安慰剂组在有氧供能（CHO组：135.1±41.2kJ，安慰剂组：129.8±35.3kJ；p=0.34）、乳酸能无氧供能（CHO组：57.6±17.1kJ，安慰剂组：53.4±15.1kJ；p=0.10）以及非乳酸能无氧供能（CHO组：10.4±8.4kJ，安慰剂组：13.2±9.2kJ；p=0.37）方面均无显著差异。总能量消耗同样无组间差异（CHO组：203.2±46.4kJ，安慰剂组：196.5±45.2kJ；p=0.15）。但CHO含漱可降低力竭时刻的RPE评分（CHO组：18.2±1.0分，安慰剂组：19.1±1.1分；p=0.02）。
结论 高强度运动过程中，CHO含漱既未延长力竭时间，也未改变能量系统的供能占比，但可降低受试者力竭时的自觉用力程度。