L-citrulline as a training booster ingredient
L-Citrulline effectively increases the concentration of L-arginine in the blood. As a result, L-Citrulline increases NO levels, muscle blood flow, and pumping muscle during exercise. L-citrulline increases maximum strength and explosive power. L-Citrulline reduces fatigue during exercise which allows more repetitions in the repetitive sets at higher volumes.
L-Citrulline as NO Booster:
L-citrulline (usually called citrulline malate) is more effective as an NO booster than arginine. Pure arginine is subject to limited bioavailability. The reason is that L-arginine is broken down to urea and ornithine by the enzyme arginase compared to L-citrulline in the gut. As a result, less arginine arrives in the bloodstream. Thus, arginine can contribute less than L-citrulline to NO synthesis.
L-Citrulline is a nonessential amino acid:
The nonessential amino acid L-citrulline is found in the diet most concentrated in the watermelon. L-citrulline serves as the precursor of the amino acid L-arginine. L-arginine is a precursor of the messenger nitrogen monoxide (NO). NO relaxes the blood vessel walls, increases blood circulation and thereby lowers blood pressure.

L-citrulline malate is part of the ATP-forming Krebs cycle and contributes to ATP regeneration. L-citrulline malate does not only improve L-citrulline absorption. It also contributes to energy production. L-Citrulline Malate increases ATP production by 30% during a training session. L-Citrulline reduces fatigue and also stimulates the regeneration of the energy storage phosphocreatine after exercise by 20%!