Effects of acute caffeine, theanine and tyrosine supplementation on mental and physical performance in athletes

Abstract

Background

A 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.

Methods

Twenty 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.

Results

Changes 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).

Discussion

The 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 registration

NCT03019523. Registered 24 January 2017.

Keywords:

• Caffeine
• Reaction time
• Mental performance
• Dietary supplements

Acknowledgements

The authors would like to thank the participants for volunteering their time and the School of Exercise and Sport Science at the University of Mary Hardin-Baylor.

Authors’ contributions

Authors’ contributions JZ, SU, KV, ES, AJ, and MT: Assisted with all aspects of data collection and presentation of the study for entire duration of study. GT and ZZ assisted with the statistical analysis/interpretation and manuscript preparation. SU: Served as laboratory coordinator managing daily operations for all investigations. CD and SM assisted all aspects of study design and development. LT: Principal investigator of the study and was primarily responsible for study development and concept and oversaw all aspects of grant management, personnel considerations and study conductions. All authors: Proofed and approved final manuscript.

Funding

The Nature’s Bounty Co. (Ronkonkoma, NY) provided the supplementation materials and funding for the current study.

Availability of data and materials

The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.

Ethics approval and consent to participate

The study design and its procedures were approved by the University of Mary Hardin-Baylor Institutional Review Board. All participants completed an informed consent form prior to their participation in this study.

Consent for publication

Not applicable.

Competing interests

Author CD and ZZ are currently employed by Nature’s Bounty. Author SM was employed by Nature’s Bounty. All authors declare no other competing interests.

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