BackgroundThe effects of consumption of isolated soy protein (ISP) for a chronic period (4 weeks) on exercise induced muscle damage (EIMD) in athletic population have never been explored.ObjectivesTo examine the effects of ISP on muscle damage indices elicited via a bout of damaging exercise.Patients and MethodsForty males (20 boxers, 20 cyclists) aged 18 - 28 years were randomly assigned to two groups (ISP and Placebo) (n = 20). All participants who engaged themselves in specific, regular training of 30 hours a week during the competitive season were included in the study. Participants consumed the supplement and the placebo for 4 weeks. The damaging exercise consisted of 100 consecutive drop-jumps. Pre and post supplementation readings of the criterion variables, highly sensitive C reactive protein (hs-cRP), creatine Kinase (CK), myeloperoxidase (MPO), isometric muscle strength, maximum aerobic capacity (VO2 max), heart rate (HR) and muscle soreness were obtained at baseline (Day 1), at 24 hours (Day 2) and at 48 hours (Day 3) following EIMD.ResultsDifferences were observed in pre and post supplementation values (P < 0.05) indicating the effectiveness of soy protein in attenuating muscle damage and enhancing muscle recovery.ConclusionsOur findings suggest that soy protein; a vegetable based supplement is effective, in ameliorating the negative effects of EIMD in trained athletic population.

PURPOSE: Branched Chain Amino Acids (BCAA) has been considered an important nutritional strategy to improve skeletal muscle protein turnover in many conditions especially following exercise induced muscle damage. Exercise induced muscle damage (EIMD), a phenomenon impairs muscle function and hampers athletic performance. The effects of consumption of BCAA for a chronic period (4 weeks) on EIMD in trained athletic population have never been explored. Therefore, the aim of the present study was to examine the effects of chronic consumption (4 weeks) of BCAA on indices of muscle damage elicited via a bout of damaging exercise in trained athletes. METHODS: Twenty trained males (20 road cyclists) aged 18-28 years were randomly assigned to two groups (BCAA and Placebo) (n = 10). The damaging exercise consisted of 100 consecutive drop-jumps. Biochemical markers including creatine kinase (CK), high sensitivity c reactive protein (hs-cRP) and myeloperoxidase (MPO), isometric knee muscle strength, muscle soreness, aerobic capacity (VO 2max ) and heart rate (HR) were measured. RESULTS: Differences were observed in pre-and post-supplementation periods among all the participants with mean height and weight values of 168.57 (4.5) cm and 61.74 (4.55) kg respectively as calculated by the anthropologist randomly allocated to the two groups in all tested parameters indicating the effectiveness of BCAA in attenuating muscle damage and enhancing muscle recovery with chronic consumption when compared to placebo, however in contrast to our expectations based on symptoms and our clinical judgment during the study statistically significant difference (P < 0.05) were noticed with biochemical indices only. CONCLUSION: Our findings suggest that chronic BCAA supplementation proved to be an effective meansof reducing muscle damage, enhancing muscle protein synthesis and recovery following EIMD as compared to placebo in well trained athletic population.