Citrulline malate has been proven to improve muscle performance because it increases aerobic energy production and delays fatigue. Citrulline malate reduces lactic acid and ammonia build up, and speeds muscle recovery by increasing the rate of creatine phosphate and ATP resynthesize. Also, citrulline malate is more effective and the same dose to increase arginine levels in the body than arginine itself. And as we know, arginine boosts No (nitric oxide) levels for better pumps, enhanced oxygen and nutrient delivery.