Effects of diets supplemented with branched-chain amino acids on the performance and fatigue mechanisms of rats submitted to prolonged physical exercise

• Published in: Nutrients 2012-11, Vol.4 (11), p.1767-1780
• Main Authors: Falavigna, Gina, Alves de Araújo, Jr, Jonas, Rogero, Marcelo Macedo, Pires, Ivanir Santana de Oliveira, Pedrosa, Rogério Graça, Martins, Jr, Eivor, Alves de Castro, Inar, Tirapegui, Julio
• Format: Article
• Language: English
• Subjects: Amino acids; Amino Acids, Branched-Chain - administration & dosage; Ammonia - blood; Animals; Diet; dietary supplements; Dose-Response Relationship, Drug; Exercise; Fatigue; Glycogen - analysis; Male; Metabolism; Muscle, Skeletal - chemistry; Nutrition; Pharmaceutical sciences; Physical Conditioning, Animal - physiology; Physical Exertion - drug effects; Plasma; Protein synthesis; Proteins; Rats; Rats, Wistar; Serotonin; sports performance; Swimming
• ISSN: 2072-6643; 2072-6643
• DOI: 10.3390/nu4111767

This study aimed to determine the effects of diets chronically supplemented with branched-chain amino acids (BCAA) on the fatigue mechanisms of trained rats. Thirty-six adult Wistar rats were trained for six weeks. The training protocol consisted of bouts of swimming exercise (one hour a day, five times a week, for six weeks). The animals received a control diet (C) (n = 12), a diet supplemented with 3.57% BCAA (S1) (n = 12), or a diet supplemented with 4.76% BCAA (S2) (n = 12). On the last day of the training protocol, half the animals in each group were sacrificed after one hour of swimming (1H), and the other half after a swimming exhaustion test (EX). Swimming time until exhaustion was increased by 37% in group S1 and reduced by 43% in group S2 compared to group C. Results indicate that the S1 diet had a beneficial effect on performance by sparing glycogen in the soleus muscle (p < 0.05) and by inducing a lower concentration of plasma ammonia, whereas the S2 diet had a negative effect on performance due to hyperammonemia (p < 0.05). The hypothalamic concentration of serotonin was not significantly different between the 1H and EX conditions. In conclusion, chronic BCAA supplementation led to increased performance in rats subjected to a swimming test to exhaustion. However, this is a dose-dependent effect, since chronic ingestion of elevated quantities of BCAA led to a reduction in performance.