The Acute Ergogenic Effect of Citrulline Malate Supplementation on Upper-Limb Strength Indices in Trained Male Weightlifters: A Crossover Study

Introduction: Citrulline malate is a nutritional supplement proposed to improve muscular performance by enhancing nitric oxide production, blood flow, and ammonia clearance. However, findings on its ergogenic benefits remain inconsistent. This study aimed to investigate the acute effects of citrulline malate supplementation on muscular strength and power in trained male weightlifters. Material & Methods: A semi-experimental, single-blind, crossover design was used with twelve male weightlifters (age 18–25) having at least two years of resistance training experience. Each participant ingested either 8 grams of citrulline malate or a placebo in two separate sessions, with a washout period in between. Muscular strength and power were evaluated using bench press, lat pulldown, handgrip, and isokinetic dynamometry. Paired t-tests (p≤ 0.05) were used to compare outcomes across conditions. Results: Overall, citrulline malate supplementation did not lead to statistically significant improvements in most strength and power indices compared to placebo. However, tow variables showed significant between-group differences: shoulder joint power during internal rotation (p = 0.022), and elbow joint strength during flexion (p= 0.025). All other improvements observed in both groups were not statistically significant. Conclusion: Acute citrulline malate intake may enhance performance in specific upper-limb movements, particularly elbow and shoulder joint flexion, but does not appear to improve general muscular strength and power across the body. Further studies with larger samples and extended supplementation durations are recommended to clarify its effectiveness.