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Eur J Appl Physiol. 2015 Feb;115(2):373-86. doi: 10.1007/s00421-014-3022-7. Epub 2014 Oct 19.

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

Author information

1
Department of Sport Science and Physical Activity, Institute for Sport and Physical Activity Research (ISPAR), University of Bedfordshire, Bedford, UK.

Abstract

PURPOSE:

The aim of this study was to investigate the effect of tyrosine (TYR) ingestion on cognitive and physical performance during soccer-specific exercise in a warm environment.

METHODS:

Eight male soccer players completed an individualised 90 min soccer-simulation intermittent soccer performance test (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 5 h and 1 h 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 vs 11.5 ± 2.4, p = 0.015) with negative responses (MISS) significantly lower (2.4 ± 1.8 vs 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 vs 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 soccer-specific exercise (iSPT) in a warm environment. This suggests that increasing the availability of TYR may improve cognitive function during exposure to exercise-heat stress.

PMID:
25326727
DOI:
10.1007/s00421-014-3022-7
[Indexed for MEDLINE]

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