Williams J H
Division of Health and Physical Education, Virginia Polytechnic Institute and State University, Blacksburg.
J Sports Med Phys Fitness. 1991 Sep;31(3):481-9.
Caffeine is one of the most widely consumed drugs in the world. There is a strong belief that caffeine is an ergogenic aid to sports performance. Although much evidence suggests that caffeine may improve endurance exercise performance, questions still remain with regard to its effects on neuromuscular function and brief, high-intensity exercise performance. At the cellular level, caffeine stimulates the central nervous system (CNS), enhances neuromuscular transmission and improves skeletal muscle contractility. The former two effects seem to have facilitative effects on activities which require quick reactions and rapid movements. This is evident in that simple and choice reaction and movement times are reduced following ingestion of small quantities of caffeine. It appears, however, that the caffeine-induced increases in muscle contractility seen in vitro do not translate into improved strength, in vivo. Acute caffeine ingestion does not seem to increase maximal voluntary contractions or maximal power output nor delay fatigue. Thus use of caffeine to improve performance in activities requiring strength and short-term endurance seems unwarrented. Further research is needed before clear conclusions can be draw regarding caffeine's effects on neuromuscular function and high-intensity exercise performance.
咖啡因是世界上消费最为广泛的药物之一。人们坚信咖啡因是一种有助于提高运动成绩的促力剂。尽管有大量证据表明咖啡因可能会改善耐力运动表现，但关于其对神经肌肉功能和短暂高强度运动表现的影响仍存在疑问。在细胞水平上，咖啡因会刺激中枢神经系统（CNS），增强神经肌肉传递并改善骨骼肌收缩性。前两种效应似乎对需要快速反应和快速动作的活动具有促进作用。这一点很明显，因为摄入少量咖啡因后，简单反应和选择反应以及动作时间都会缩短。然而，体外观察到的咖啡因引起的肌肉收缩性增加似乎并未转化为体内力量的提高。急性摄入咖啡因似乎不会增加最大自主收缩或最大功率输出，也不会延迟疲劳。因此，在需要力量和短期耐力的活动中使用咖啡因来提高表现似乎没有依据。在能够就咖啡因对神经肌肉功能和高强度运动表现的影响得出明确结论之前，还需要进一步的研究。
