Citrulline improves exercise performance by 10-21 percent

Supplementation with citrulline, an amino acid metabolite, may have several beneficial effects on health and performance.  

Citrulline is naturally produced in the body during the urea cycle and nitric oxide synthesis. Citrulline may play a role in vascular dilation, removal of ammonia, energy production, and even protein synthesis. Here’s a recap of two very recent studies that investigated supplementation with citrulline in humans.

Resistance-trained men performed two series of exercise tests after supplementing with citrulline malate (8 grams) or a placebo. Tests were separated by one week. Compared to placebo, performance was significantly greater after citrulline supplementation as evidenced by greater chin-ups (13%), reverse chin-ups (21%), and push-ups (10%).

Based on work in malnourished rats that showed feeding them a citrulline-enriched diet increased protein synthesis, researchers set out to test whether this effect could be observed in humans. Healthy men and women were provided a low-protein diet (8% of total calories) for 3 days to induce a slight protein deficit. After this period, subjects ingested either citrulline or an equal amount of non-essential amino acids over the next 8 hours while measures of protein synthesis were determined. The rate of muscle protein synthesis was 22% higher after citrulline ingestion. There were no differences in anabolic hormones.

This is the first study to show that citrulline specifically stimulates muscle protein synthesis in the fasted state in healthy people on a low-protein diet. These studies open the door to new roles of citrulline supplementation to enhance muscle building and performance. 

Previous Next Back to Top
More Related Articles