Effect of tyrosine ingestion on cognitive and physical performance utilising an intermittent soccer performance test (iSPT) in a warm environment

Abt, Grant.; Dascombe, Benjamin.; Coull, Nicole A..; Watkins, Samuel L..; Aldous, Jeffrey W. F..; Warren, Lee K..; Chrismas, Bryna C. R..; Mauger, Alexis R..; Taylor, Lee.; Aldous, Jeffrey W F.; Chrismas, Bryna C R.

doi:10.1007/s00421-014-3022-7

Authors

Bryna C. R. Chrismas

Jeffrey W. F. Aldous

Nicole A. Coull

Samuel L. Watkins

Jeffrey W F Aldous

Lee K. Warren

Benjamin Dascombe

Bryna C R Chrismas

Alexis R. Mauger

Dr Grant Abt G.Abt@hull.ac.uk
Reader in Sport and Exercise Physiology and Head of Department for Sport, Health and Exercise Science

Lee Taylor

Abstract

Purpose: The aim of this study was to investigate the effect of tyrosine ingestion on cognitive and physical performance during soccer-specific exercise in a warm environment. Methods: Eight male soccer players completed an individualised 90-minute soccer-simulation (iSPT), on a non-motorised treadmill, on two occasions, within an environmental chamber (25°C, 40% RH). Participants ingested tyrosine (TYR; 250 mL sugar free drink plus 150 mg.kg body mass⁻¹ TYR) at both 5h and 1h pre-exercise or a placebo control (PLA; 250 mL sugar free drink only) in a double-blind, randomised, crossover design. Cognitive performance (vigilance and dual-task) and perceived readiness to invest physical effort (RTIPE) and mental effort (RTIME) were assessed: pre-exercise, half-time, end of half-time and immediately post-exercise. Physical performance was assessed using the total distance covered in both halves of iSPT. Results: Positive vigilance responses (HIT) were significantly higher (12.6 ± 1.7 v 11.5 ± 2.4, p = 0.015) with negative responses (MISS) significantly lower (2.4 ± 1.8 v 3.5 ± 2.4, p = 0.013) in TYR compared to PLA. RTIME scores were significantly higher in the TYR trial when compared to PLA (6.7 ± 1.2 v 5.9 ± 1.2, p = 0.039). TYR had no significant (p > 0.05) influence on any other cognitive or physical performance measure. Conclusion: The results show that TYR ingestion is associated with improved vigilance and RTIME when exposed to individualised soccerspecific exercise (iSPT) in a warm environment. This suggests that increasing the availability of TYR may improve cognitive function during exposure to exercise-heat stress.

Publication Date	2015-02
Journal	European journal of applied physiology
Print ISSN	1439-6319
Electronic ISSN	1439-6327
Publisher	Springer Verlag
Peer Reviewed	Peer Reviewed
Volume	115
Issue	2
Pages	373-386
Institution Citation	Coull, N. A., Watkins, S. L., Aldous, J. W. F., Warren, L. K., Chrismas, B. C. R., Mauger, A. R., …Taylor, L. (2015). Effect of tyrosine ingestion on cognitive and physical performance utilising an intermittent soccer performance test (iSPT) in a warm environment. European journal of applied physiology, 115(2), 373-386. https://doi.org/10.1007/s00421-014-3022-7
DOI	https://doi.org/10.1007/s00421-014-3022-7
Keywords	Central fatigue; Tyrosine; Cognitive function; Intermittent exercise; Heat
Publisher URL	http://link.springer.com/article/10.1007/s00421-014-3022-7
Copyright Statement	©2015 University of Hull
Additional Information	Author's accepted manuscript of article published in: European journal of applied physiology, 2015, v.115, issue 2. The final publication is available at Springer via http://dx.doi.org/10.1007/s00421-014-3022-7