The effects of branched chain amino acid supplementation on indicators of muscle damage after prolonged strenuous exercise

Branched-chain amino acid (BCAA) supplementation is becoming more widely used by athletes in an attempt to improve their recovery between training or competition. This study examined the effects of the supplementation on indicators of muscle damage after intense prolonged exercise. Sixteen male subjects were used in the study with eight taking BCAA supplementation and eight acting as the control group. The experimental group were required to take the manufacturer's recommended dose for the 14 days oi iesiing. For the seven days before the exercise test both groups had their blood analysed every second day for creatine kinase and lactate dehydrogenase which have been shown to be accurate indicators of muscle damage. The exercise test was a 120 minute bicycle ride at 70% of their predetermined VO2max. Directly after the exercise and hourly for 4 hours all subjects again had blood samples analysed. The experimental group continued to take supplementation for 7 days after the test and all subjects had their blood analysed every second day. Subjects were also required to keep activity to a minimum and have their diet analysed during the 14 days and manipulated if necessary to ensure that the recommended daily Intake of BCAA's were being consumed as part of their normal diet. Results indicated that all subjects' diets did not require manipulation as they all consumed the recommended daily intake of BCAA's in their normal diet. No significant differences were found between any of the two enzyme values in the 7 days prior to the test. There were, however, significant changes in pre-exercise and post-exercise values for LDH at 2 hrs., 3 hrs., 4 hrs., 1 day, 2 days and 4 days after the test (p<0.05). There were also significant changes in pre -exercise and post-exercise values for CK at 4 hrs., 1 day, 2 days and 4 days after the test. The BCAA was shown to significantly (p<0.05) reduce this change in LDH at 3 hrs., 4 hrs. and 1 day and CK at 4 hrs., 1 day and 2 days post exercise. These results indicate that supplementary Branched Chain Amino Acids significantly reduce the levels of the intramuscular enzymes creatine kinase and lactate dehydrogenase after prolonged strenuous exercise. This suggests that the supplementation may reduce muscle damage.