[Effects of branched amino acids in endurance sports: a review].

Introduction: The report issued by the European Food Safety Agency (EFSA) in 2010 on nutrition and health claims, shows that there is no scientific evidence to support supplementation with branched chain amino acids (BCAAs). The aim of this study is to analyze the effects of consumption of BCAAs in endurance sports.

Methods: A literature review on the current state of the effect of consumption of dietary supplements of BCAAs. We conducted a search in the PubMed database and snowball strategy.

Inclusion Criteria: Spanish / English randomized clinical trial related to the consumption of BCAAs, leucine, valine and isoleucine in endurance sports and its effects on muscle damage, athletic performance, central fatigue, anabolic signals during recovery and immune system response published in any country until May 2014.

Results: Out of 330 studies identified, 14 met the inclusion criteria. The mean of subjects participating in the study was (11.36±7.43). Only two studies included a group of women. The sports that we found in the studies were: run, cycling, combining cycling and running, Olympic distance triathlon and one study included 2 groups of athletes (Olympic distance triathletes and runners). The effects of BCAAs and muscle damage, athletic performance, central fatigue, anabolic signals during recovery period and immune response were studied at different times: before, during and after training or a combination of these.

Discussion: It is observed that there is a lesser degree of pain and muscle damage, less perceived exertion and mental fatigue, greater anabolic response in recovery period and improved immune response when supplemented with BCAAs, notwithstanding its decision before or during physical activity does not improve athletic performance. No consensus was found in the dose and timing of the most effective decision, although it is more effective if there is 2-3/1/1g relationship between leucine / isoleucine and valine amino acids.