August 13, 2015

Recent research looks at the potential benefits of the amino acid L-citrulline, known as citrulline, as a workout recovery supplement and to help boost immunity after exercise.

Researchers at a University in Spain have found that citrulline can help preserve immune function after strenuous exercise. This is important because strenuous exercise causes a decline in immune function which starts when the exercise ends. The drop in immune function is associated with weakened function of white blood cells called PMN’s, which are the body’s first line of defense against infection.

The research team in Spain studied the effect of the amino acid L-citrulline on white blood cell function in elite cyclists before and after a race. Six thousand milligrams of L-citrulline malate (a heaping teaspoon of powder) prevented the decline in PMN function caused by a 3-hour race, when compared to placebo.

In research done in France, citrulline was shown to prevent post-exercise fatigue and muscle soreness in untrained athletes, when taken after exercise. This study indicates the potential beneficial use of citrulline as a workout recovery supplement.

However, a study done at the Human Performance Laboratory at East Carolina University found that the use of citrulline before exercise may impair performance of untrained athletes.