β-Alanine improves punch force and frequency in amateur boxers during a simulated contest


Journal Title (Medline/Pubmed accepted abbreviation): Int. J. Sport Nutr. Exerc. Metab.
Year: 2012
Volume: 55
Issue: 5
Page numbers: 331-337
Summary of background and research design:
Background:  Boxing is a high-intensity sport that requires both aerobic and anaerobic energy pathways for force generation and endurance, respectively.  Due to the high intensity of boxing, an increase in lactic acid concentration in the muscles and, therefore, acidification of the muscles could be contributing to fatigue.  β-alanine is a promising supplement to maintain the pH of the muscles since it can increase the amount of carnosine, a natural buffer, inside muscle cells by about 40-85%.

Hypothesis:  β-Alanine supplementation at 6 g/day for 4 wks will improve punch performance (force and frequency) during a simulated boxing match.

Subjects: Sixteen competitive amateur boxers, age 25 ± 4 y

Experimental design:  block randomized based on number and force of punches during baseline testing, placebo-controlled, single-blind, parallel groups

Treatments:
β-Alanine: 1.5 g β-alanine 4 times per day (6 g/day total) in capsules, taken at least 2 hrs apart and preferably after a meal containing protein.
Placebo: Maltodextrin

Protocol:  The participants first reported to the laboratory for familiarization with the testing procedures.  Then, they completed baseline testing which included a simulated boxing contest.  On a punching bag equipped with a force transducer, they followed a standardized punch combination every 12 sec for 2 min, 50 sec.  Then, they performed maximal punching for 10 sec.  After a 60 sec rest, they repeated the routine to yield 3 ×3 min rounds.  Heart rate was measured between rounds and, immediately after the last round, a blood sample was collected for analysis of blood lactate concentration.  After group assignment, they were given a supplement to consume for 28 days.  On the 29th day, the participants repeated the same simulated boxing contest as at baseline.  During the supplementation period, the participants completed questionnaires regarding side effects.
Summary of research findings: 
  • Heart rate was not different between groups before or after supplementation.  However, heart rate increased with increasing rounds during the contest.
  • Blood lactate levels were significantly greater in the β-alanine group compared to the placebo group after boxing (p = 0.0002).  There was no difference in blood lactate concentrations before vs. after supplementation in the placebo group.  This implies that the muscles of those that consumed β-alanine had better buffering capacity.
  • Those that consumed β-alanine punched with greater force (p = 0.002) after supplementation compared to before.  There were no differences in punch force for those that consumed the placebo (p = 0.537).
  • Similarly, during the last 10 sec of each round, those that consumed the β-alanine completed more punches after supplementation compared to baseline (p = 0.003) while those that consumed the placebo showed no improvement (p = 0.094).
  • None of the participants reported side effects, including flushing or a sense of tingling, which have been noted in several other studies.

Key practice applications: β-Alanine supplementation led to an increase in boxing performance (measured by force of punches) and exercise capacity (measured by number of punches) in a simulated boxing competition.  It is thought that β-alanine increased that amount of buffering capacity in the muscle, thereby allowing a greater accumulation of lactate in muscle before fatigue was manifested.

Key search terms for this article (5-7 terms): β-alanine, boxing, exercise capacity, carnosine, pH, lactate
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