Branch chain amino acids enhances post exercise sport specific skill test performance in team sport athletes

Nigel K. Stepto, Benjamin Shipperd, Graeme Hyman, Bernie V. McInerney, David B. Pyne

Research output: Contribution to journalMeeting abstractpeer-review


Purpose: This study investigated the effects of branch chain amino acid (BCAA) supplementation on attenuating fatigue-induced decrements in exercise and motor-skill performance in Australian Football players.

Methods: Sub-elite players (n=15) were recruited from local football clubs and provided written informed consent. The players undertook 5 testing sessions separated by 7 days. The first two sessions involved familiarisation of subjects with the reactive agility test (RAT) and reactive motor skills test (RMST). Players performed the 20 m shuttle run and 20 m sprint test and assessed for height, mass and sum of skinfolds. Session three was a control trial where subjects received a standardized meal 3 h before testing. Players ingested a 600 ml carbohydrate drink, and then completed a pre-exercise RMST and RAT, followed by a 30 min of fatiguing exercise protocol and post-exercise testing. Session 4 and 5 were identical to session 3 except the athletes ingested (using a double blinded randomized crossover design) a tryptophan/serotonin depleting or loading BCAA mixture prior to the standardized meal. Blood samples were taken for analysis of plasma amino acid concentrations.

Results: Mean overall repetition time of the RAT after fatiguing exercise was moderately improved by -5.2±3.4% (mean±90% confidence limits; effect size [ES] -0.45±0.28) in the depleting trial compared with the control. The depleting and loading supplements had a divergent effect on mean repetition time after fatiguing exercise in RMST: depleting serotonin resulted in a small improvement (-3.0±2.7% ES -0.25±0.21) in contrast to the small decrement (2.4±2.7% ES 0.20±0.21) after ingestion of loading mixture compared to the control trial. Serotonin depletion elicited a moderate improvement in RMST repetition time after fatiguing exercise compared to loading (-5.3±4.3%, ES -0.43±0.33). Skill performance after exercise was moderately improved (∼8%) after exercise in both depleting and loading trials compared the control.

Conclusions: High dose serotonin depleting BCAA supplementation 3 h prior to intermittent high intensity exercise substantially improved reactive agility and motor skill performance in Australian Football players.Supported by Australian Institute of Sport Grant 995147
Original languageEnglish
Article number2864
Pages (from-to)777
Number of pages1
JournalMedicine and Science in Sports and Exercise
Issue number5
Publication statusPublished - May 2010
Event57th Annual Meeting of the American-College-Sports-Medicine/Inaugural World Congress on Exercise is Medicine - Baltimore, Moldova, Republic of
Duration: 5 Jun 2010 → …


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