During exercise, and especially 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, our Threshold™ formula is designed to help boost your intramuscular buffering system so that you can train harder, longer.