The effect of citrulline on delayed onset muscle soreness (DOMS) and aerobic and anaerobic endurance in sub elite athletes

Introduction: Athletes can improve their performance by adjusting their diet and consuming citrulline, a nonessential amino acid that affects VO2max by increasing plasma arginine concentration and nitric oxide production. Objective: This study investigates the impact of citrulline supplementation on athletes' performance and endurance after eccentric exercise, focusing on its effects on VO₂max and DOMS. Methodology: A quasi-experimental study involved 36 badminton athletes in citrulline (CIT) and placebo (PLA) groups. Citrulline and cornstarch capsules were given daily for seven days before the post-test. Anaerobic and aerobic endurance tests (RAST and MFT) were conducted, and DOMS levels were measured using the Visual Analogue Scale (VAS). Results: The CIT group experienced significant improvements in anaerobic endurance at posttest 1, but not at posttest 2. In aerobic endurance, the CIT group recorded significant improvements at both posttests, with the largest effect at posttest 2 (d = 1.892). In addition, DOMS soreness levels decreased more rapidly in the CIT group than in the PLA group, with significant differences (p < 0.05) at 24, 48, and 72 hours after eccentric exercise. Discussion: Citrulline supplementation increased aerobic endurance and accelerated DOMS recovery, consistent with the findings of Pérez-Guisado & Jakeman (2010). The small effect on anaerobic endurance, on the other hand, fits with the research of Rhim et al. (2020), showing that response variation depends on parameters. Conclusions: Citrulline supplementation accelerates muscle soreness recovery and improves aerobic and anaerobic endurance in athletes by increasing nitric oxide production and reducing post-exercise muscle soreness.