Four Weeks of Supplementation With Isolated Soy Protein Attenuates Exercise-Induced Muscle Damage and Enhances Muscle Recovery in Well Trained Athletes: A Randomized Trial.

Background: The 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. Objectives: To examine the effects of ISP on muscle damage indices elicited via a bout of damaging exercise. Patients and Methods: Forty 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. Results: Differences 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. Conclusions: Our findings suggest that soy protein; a vegetable based supplement is effective, in ameliorating the negative effects of EIMD in trained athletic population. [ABSTRACT FROM AUTHOR]