Citrulline and exercise performance

Objective: To assess the relationship between citrulline supplementation and exercise performance. The review synthesized acute and chronic intervention studies across endurance and resistance exercise settings, focusing on time-to-exhaustion, perceived exertion, blood flow-related markers, and postexercise recovery. Citrulline appeared to improve performance most consistently in protocols involving repeated high-intensity efforts or substantial metabolic stress, where modest changes in fatigue resistance could be detected. Proposed mechanisms included enhanced nitric oxide availability, improved ammonia handling, and better buffering of exercise-induced metabolic byproducts. The evidence was less convincing for maximal strength tasks or highly trained athletes with optimized baseline status. Overall, the findings suggest that citrulline may have a small but meaningful ergogenic effect in selected contexts, though publication bias, heterogeneous doses, and inconsistent outcome measures limit confidence. The article positions citrulline as a plausible sports-nutrition aid with potential benefit, but not a universally effective performance enhancer.