Citrulline improves sports endurance
Increasing blood flow is key to increasing endurance. Nitric oxide (NO) helps relax and dilate blood vessels, and arginine can produce NO. Citrulline can also help produce NO by increasing arginine levels.

In this study, 10 healthy men completed a moderate to severe cycling exercise on days six and seven of a 7-day supplementation period with placebo, 6 grams of L-arginine, or 6 grams of L-citrulline per day, in three alternating phases. L-arginine plasma levels increased during both the L-arginine and L-citrulline phases, as did signs of increased NO production.

The men taking either supplement had a greater time to exhaustion during the cycling test than placebo: L-citrulline phase (670 seconds), L-arginine phase (615 seconds) and placebo phase (595 seconds). The L-citrulline advantage was attributed to better oxygen uptake because they found a 13.9% higher oxygenation of their blood after the exercise. There was no significant difference between the L-citrulline and L-arginine phases during moderate-intensity cycling. Blood pressure was lower during the L-citrulline phase compared to L-arginine or placebo phases.

Reference: Journal of Applied Physiology; 2015, Vol. 119, No. 4, 385-95.
Next Back to Top
More Related Articles