Effects of Glutamine Supplementation Combined with Exercise on Isokinetic Performance and Biochemical Parameters After Anterior Cruciate Ligament (ACL) Reconstruction: A Randomized Controlled Trial

Objective To evaluate the effects of glutamine supplementation combined with an exercise program on isokinetic performance, biochemical parameters, and muscle asymmetry indices in individuals undergoing rehabilitation following ACL reconstruction. Design A 6-week randomized controlled trial was conducted, assigning participants to either a glutamine supplementation group (ExGln) or a placebo group (ExPla), both undergoing a standardized exercise program. Setting The study was performed in a sports medicine facility with access to isokinetic testing and biochemical analysis. Participants A total of 30 participants who had undergone ACL reconstruction surgery were included, with 15 in each group. Methods Peak torque and muscle asymmetry of knee extensors and flexors were assessed via isokinetic testing. Biochemical analyses (glucose, lipid profile, liver enzymes) were conducted pre– and post-intervention. Wilcoxon and Mann–Whitney U tests were used for intra– and intergroup comparisons, respectively. Results The ExGln group showed significant improvements in peak torque for the involved limb extensors (p=0.001) and flexors (p=0.001), as well as reductions in extensor and flexor asymmetry indices (p=0.001 and p=0.018, respectively). Additionally, significant reductions were observed in C-LDL, C-HDL, and triglycerides levels in the ExGln group (p=0.006, p=0.003, and p=0.003, respectively). The intergroup analysis indicated significant differences in alkaline phosphatase levels (p=0.031). No adverse effects were reported. Conclusion Glutamine supplementation combined with a structured exercise program significantly enhanced isokinetic performance and improved biochemical parameters, suggesting a beneficial role in postoperative rehabilitation following ACL reconstruction. Further studies with larger sample sizes are recommended to validate these findings.