Supplementation of inosine has impact on many processes that influence physical performance such as oxygen supply of muscle tissue which influences positively musclc work which is more efficient and it has impact on the whole training that is more efficient. Another good effect is that Inosine increases ATP level. For endurance sports, the effect of decreased lactic acid creation when maintaining same performance level is significant. Inosine is suitable with its effects mainly for endurance and power-endurance sports.