During high-intensity training, glucose and glycogen are broken down for energy. In the process, hydrogen ions (H+) are also produced within the muscles. H+ accumulation causes the muscles to become more acidic and ultimately leads to fatigue. Packed with beta-alanine, histidine, and phosphates, Optimum Nutrition's Threshold formula is designed to help boost your intramuscular buffering system so you can train harder, longer. 1.6 grams of Beta Alanine 550 mg of L-Histidine Supports Carnosine Synthesis Instructions : One scoop of ON's Beta-Alanine Powder provides 1.6 grams of pure Beta-Alanine. Stack the unflavored version with shakes and other powders to get you closer to your daily total, or mix up the flavored version in cold water. Getting about 3 grams a day should be your goal for training performance.