We have already covered oxygen cocktails in the section on supplementation products for performance enhancement. Here we add that, as well as having the potential to improve the performance of the aerobic mechanism for metabolic energy production, they may also be useful in disposing of fatigue in the alactacidic anaerobic mechanism. More specifically, once the latter’s capacity to produce energy has been exhausted due to depletion of phosphocreatine stores, the body, at the end of the effort, will use oxygen to restore reserves by rephosphorylating creatine. During the period in which the body carries out this operation, the need for oxygen increases compared to normal (in physiology, this is called oxygen debt), which is why the fatigued athlete tends to hyperventilate. Some believe that providing the body with more oxygen through supplementation will facilitate and speed up this process. However, there is no evidence to prove this.