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Oral tyrosine supplementation improves exercise capacity in the heat.

Tumilty, Les, Davison, Glen, Beckmann, Manfred, Thatcher, Rhys (2011) Oral tyrosine supplementation improves exercise capacity in the heat. European journal of applied physiology, 111 (12). pp. 2941-2950. ISSN 1439-6327. (The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided) (KAR id:43472)

The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided. (Contact us about this Publication)

Abstract

Increased brain dopamine availability improves prolonged exercise tolerance in the heat. It is unclear whether supplementing the amino-acid precursor of dopamine increases exercise capacity in the heat. Eight healthy male volunteers [mean age 32 ± 11 (SD) years; body mass 75.3 ± 8.1 kg; peak oxygen uptake ([Formula: see text]) 3.5 ± 0.3 L min(-1)] performed two exercise trials separated by at least 7 days in a randomised, crossover design. Subjects consumed 500 mL of a flavoured sugar-free drink (PLA), or the same drink with 150 mg kg body mass(-1) tyrosine (TYR) in a double-blind manner 1 h before cycling to exhaustion at a constant exercise intensity equivalent to 68 ± 5% [Formula: see text] in 30°C and 60% relative humidity. Pre-exercise plasma tyrosine:large neutral amino acids increased 2.9-fold in TYR (P < 0.01), while there was no change in PLA (P > 0.05). Subjects cycled longer in TYR compared to PLA (80.3 ± 19.7 min vs. 69.2 ± 14.0 min; P < 0.01). Core temperature, mean weighted skin temperature, heart rate, ratings of perceived exertion and thermal sensation were similar in TYR and PLA during exercise and at exhaustion (P > 0.05) despite longer exercise time in TYR. The results show that acute tyrosine supplementation is associated with increased endurance capacity in the heat in moderately trained subjects. The results also suggest for the first time that the availability of tyrosine, a nutritional dopamine precursor, can influence the ability to subjectively tolerate prolonged submaximal constant-load exercise in the heat.

Item Type: Article
Subjects: Q Science
Divisions: Divisions > Division of Natural Sciences > School of Sport and Exercise Sciences
Depositing User: Glen Davison
Date Deposited: 17 Oct 2014 21:28 UTC
Last Modified: 16 Feb 2021 12:56 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/43472 (The current URI for this page, for reference purposes)
Davison, Glen: https://orcid.org/0000-0003-4340-0074
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