CORE CHAMPS L-CITRULLINE PERFORMANCE AT ITS CORE – BRED TO BE A CHAMPION! CORE CHAMPS L-CITRULLINE supports vasodilation through nitric oxide production, helping to improve blood flow and muscle pumps during a workout. L-Citrulline Malate is an amino acid that works to raise both arginine and ornithine plasma levels more efficiently and for longer periods of time than just l-arginine supplementation alone. L-Citrulline is one of the most promising pre-workout supplement ingredients for the purpose of building muscle.