BackgroundA limited amount of research has demonstrated beneficial effects of caffeine and theanine supplementation for enhancement of mental performance. The purpose of this investigation was to determine whether the acute ingestion of a supplement containing caffeine, theanine and tyrosine improves mental and physical performance in athletes.MethodsTwenty current or former male collegiate athletes (age: 20.5 ± 1.4 y; height: 1.82 ± 0.08 m; weight: 83.9 ± 12.6 kg; body fat: 13.8 ± 5.6%) completed this randomized, double-blind, placebo-controlled crossover trial. After familiarization, each participant completed two identical testing sessions with provision of a proprietary dietary supplement (SUP) containing caffeine theanine and tyrosine or a placebo (PL). Within each testing session, participants completed assessments of mental and physical performance before and after provision of SUP or PL, as well as after two rounds of exercise. Assessments were performed using a performance testing device (Makoto Arena) that evaluated multiple aspects of mental and physical performance in response to auditory and visual stimuli. Testing was performed both with the body in a static position and during dynamic movement. General linear models were used to evaluate the effects of SUP and PL on performance.ResultsChanges in movement accuracy during performance assessment were greater following SUP ingestion as compared to PL for both static and dynamic testing (SUP: + 0.4 to 7.5%; PL: − 1.4 to 1.4% on average; p < 0.05). For dynamic testing, the change in number of targets hit was higher and the change in average hit time was lower with SUP as compared to PL (p < 0.05). However, there were no differences between conditions for the changes in number of targets hit or average hit time during static testing. There were no differences in changes of subjective variables during either condition, and performance measures during the two rounds of exercise did not differ between conditions (p > 0.05).DiscussionThe present results indicate that a combination of a low-dose of caffeine with theanine and tyrosine may improve athletes’ movement accuracy surrounding bouts of exhaustive exercise without altering subjective variables. Based on this finding, supplementation with caffeine, theanine and tyrosine could potentially hold ergogenic value for athletes in sports requiring rapid and accurate movements.Trial registrationNCT03019523. Registered 24 January 2017.

中文翻译：

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急性咖啡因、茶氨酸和酪氨酸补充剂对运动员身心表现的影响

背景有限数量的研究表明，补充咖啡因和茶氨酸对提高精神表现有有益作用。本次调查的目的是确定急性摄入含有咖啡因、茶氨酸和酪氨酸的补充剂是否能改善运动员的心理和身体表现。方法 20 名现任或前任男大学生运动员（年龄：20.5 ± 1.4 岁；身高：1.82 ± 0.08 m ；体重：83.9 ± 12.6 kg；体脂：13.8 ± 5.6%）完成了这项随机、双盲、安慰剂对照的交叉试验。熟悉后，每位参与者完成了两次相同的测试，并提供含有咖啡因茶氨酸和酪氨酸的专有膳食补充剂 (SUP) 或安慰剂 (PL)。在每个测试阶段，参与者在提供 SUP 或 PL 前后以及两轮运动后完成了对心理和身体表现的评估。评估是使用性能测试设备（Makoto Arena）进行的，该设备评估了对听觉和视觉刺激的心理和身体表现的多个方面。测试是在身体处于静态位置和动态运动期间进行的。使用一般线性模型来评估 SUP 和 PL 对性能的影响。结果在静态和动态测试中，与 PL 相比，摄入 SUP 后运动准确性的变化更大（SUP：+ 0.4 至 7.5%；PL：-平均 1.4% 至 1.4%；p < 0.05)。对于动态测试，与 PL 相比，SUP 命中目标数量的变化更大，平均命中时间的变化更小（p < 0.05）。然而，在静态测试期间，目标命中数或平均命中时间变化的条件之间没有差异。两种情况下主观变量的变化没有差异，两轮运动期间的表现测量在不同情况下没有差异（p > 0.05）。讨论目前的结果表明，低剂量咖啡因与茶氨酸和酪氨酸可以在不改变主观变量的情况下提高运动员在剧烈运动中的运动准确性。基于这一发现，补充咖啡因，茶氨酸和酪氨酸可能对需要快速准确运动的运动员具有增效作用。试验注册 NCT03019523。2017 年 1 月 24 日注册。