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

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

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