GU Roctane Ultra Endurance Energy Gel is a re-engineered formulation of the GU you already know and love. Roctane has added amino acids to slow lactic acid production, serve as fuel, aid recovery from hard efforts, and mitigate fuzzy-headed weariness. Also, the addition of OKG, an amino acid complex that mitigates catabolic effects that break down muscle tissue, helps to minimize fatigue and muscle damage during repeated days of hard efforts.