Acceleration. It can mean that final kick to the finish on your run or launching a surprise attack at the base of a climb. In the case of Klean Endurance, it means a great-tasting chewable tablet that supports the natural way the human body produces energy.† Klean Endurance is an all-natural D-Ribose supplement clinically shown to help restore and replenish energy.† These chews also support cardiac function and reduce muscle soreness and fatigue.† Training for a triathlon? Planning an epic mountain climb? Give yourself a boost whenever and wherever you need it. Give yourself Klean Endurance.