Roelands Bart, Hasegawa Hiroshi, Watson Phillip, Piacentini Maria Francesca, Buyse Luk, De Schutter Guy, Meeusen Romain R
Department of Human Physiology and Sports Medicine, Faculty of Physical Education and Physiotherapy, Vrije Universiteit Brussel, Brussels, Belgium.
Med Sci Sports Exerc. 2008 May;40(5):879-85. doi: 10.1249/MSS.0b013e3181659c4d.
Acute bupropion (dopamine/noradrenaline reuptake inhibitor) administration significantly improved time trial performance and increased core temperature in the heat (30 degrees C).
The present study was performed to examine the effect of a dopaminergic reuptake inhibitor on exercise capacity and thermoregulation during prolonged exercise in temperate and warm conditions.
Eight healthy well-trained male cyclists participated in this study. Subjects ingested either placebo (PLA; 20 mg) or methylphenidate (MPH; Ritalin; 20 mg) 1 h before the start of exercise in temperate (18 degrees C) or warm (30 degrees C) conditions and cycled for 60 min at 55% Wmax, immediately followed by a time trial (TT; PLA18 and MPH18; PLA30 and MPH30) to measure exercise performance.
MPH did not influence TT performance at 18 degrees C (P = 0.397). TT was completed 16% faster in MPH30 (38.1 +/- 6.4 min) than in PLA30 (45.4 +/- 7.3 min; P = 0.049). In the heat Tcore was significantly higher at rest (P = 0.009), and throughout the TT in MPH30 (P < 0.018), reaching values above 40 degrees C. Throughout MPH30, heart rates were significantly higher (P < 0.05).
These results show that MPH has a clear ergogenic effect that was not apparent in 18 degrees C. The combination of a dopamine reuptake inhibitor and exercise in the heat clearly improved performance and caused hyperthermia without any change in the perception of effort or thermal stress compared with the PLA trial. This response may potentially increase the risk of developing heat illness during exercise in individuals taking drugs of this nature.
急性服用安非他酮（多巴胺/去甲肾上腺素再摄取抑制剂）可显著改善计时赛成绩，并在高温（30摄氏度）环境下提高核心体温。
本研究旨在探讨多巴胺能再摄取抑制剂在温带和温暖条件下长时间运动期间对运动能力和体温调节的影响。
八名健康且训练有素的男性自行车运动员参与了本研究。在温带（18摄氏度）或温暖（30摄氏度）条件下运动开始前1小时，受试者服用安慰剂（PLA；20毫克）或哌甲酯（MPH；利他林；20毫克），并以最大摄氧量的55%骑行60分钟，随后进行计时赛（TT；PLA18和MPH18；PLA30和MPH30）以测量运动表现。
MPH对18摄氏度时的TT成绩无影响（P = 0.397）。MPH30组完成TT的速度比PLA30组快16%（38.1±6.4分钟对45.4±7.3分钟；P = 0.049）。在高温环境下，MPH30组静息时的核心体温显著更高（P = 0.009），且在整个TT过程中也更高（P < 0.018），达到40摄氏度以上。在整个MPH30组中，心率显著更高（P < 0.05）。
这些结果表明，MPH具有明显的促力作用，在18摄氏度时并不明显。与PLA试验相比，多巴胺再摄取抑制剂与高温环境下的运动相结合明显提高了运动表现并导致体温过高，而主观用力感觉或热应激却没有任何变化。这种反应可能会增加服用此类药物的个体在运动期间发生热疾病的风险。
