β-alanine supplementation improves YoYo intermittent recovery test performance


Journal Title (Medline/Pubmed accepted abbreviation): J. Int. Soc. Sports Nutr.
Year: 2012
Volume: 9
Article: 39
doi: 10.1186/1550-2783-9-39
Summary of background and research design:
Background:Carnosine is a protein that is found in high concentrations in skeletal muscle.  It is composed of two amino acids, histidine and β-alanine.  Carnosine buffers protons that are produced during exercise, thereby permitting more exercise to be performed before fatigue sets in.  β-Alanine supplementation has been shown to be most effective in high intensity, short duration exercise that lasts less than 60 sec.
The YoYo exercise test was designed to emulate play during a soccer match.   It involves alternating between high intensity exercise and active recovery (walking/jogging).  The YoYo IR2 test, specifically, closely evaluates how athletes perform on repeated, high-intensity exercises that involve both aerobic and anaerobic energy pathways

Hypothesis: Daily β-alanine supplementation will improve the performance of soccer players on the YoYo IR2 intermittent recovery test.

Subjects:  Seventeen omnivorous soccer players from the United Kingdom, age 22 ± 4 y.

Experimental design: randomized, double-blind, placebo-controlled

Treatments:
β-Alanine- One 800 mg tablet of CarnoSyn™ β-alanine was ingested every 3-4 hours to equal 3.2 g/day.
Placebo- the same dose and dosing regimen but with maltodextrin

Protocol: The participants were first familiarized with the YoYo IR2 physical evaluation.  They then performed it twice, separated by 12 weeks of supplementation with either β-alanine or the placebo.  The YoYo IR2 was completed as follows.  After a 5 min warm up, participants completed shuttle runs (40 m total) with a 10 second (10 m) walk recovery in between.  The runs were performed at increasing speeds as dictated by an audio recording.  The test continued until the participant could not keep up with the recording or chose to stop.  Total distance covered was recorded.
Summary of research findings: 
  • Although a tingling sensation is often reported with β-alanine supplementation, none of the participants in this study reported those feelings.
  • There was no difference in performance between the two groups before supplementation.
  • After supplementation, those that were consuming β-alanine performed significantly better than before supplementation (+34.3 ± 22.5%).  Participants in the control group performed similarly as before.
  • Eight of the 9 participants in the β-alanine group improved, while the ninth participant performed exactly the same pre- and post-supplementation.  In the control group, 25% improved while 75% performed worse after supplementation.

Key practice applications: Twelve weeks of supplementation with 3.2 g β-alanine per day improved the performance of amateur soccer players on a soccer match-simulated exercise task.

Key search terms for this article (5-7 terms): β-alanine, carnosine, buffering, pH, YoYo
Google Tracking Google Plus Tracking Twitter Tracking