During physical exertion and increasing duration, the body also uses BCAAs to provide energy and attacks the body's own reserves of muscle tissue if there is no supply of BCAA. Endurance athletes therefore benefit from BCAA intake during sporting performance because the body's own reserves are conserved. Strength athletes appreciate BCAA, especially leucine, which serves as an anabolic signalling agent for muscle protein synthesis, which is crucial for building and maintaining muscle mass and ultimately also has a positive effect on recovery. Because declining BCAA levels have a negative impact on athletes' perception of fatigue and exertion, endurance athletes ideally use BCAA during endurance events such as cycling and bike marathons, Ironman, long-distance triathlons and ultra runs, preferably in combination with recovery products. Strength athletes can take BCAA shortly before their workout and/or supplement their protein shake after training.