Alactic anaerobic metabolism
The biochemical process of alactic anaerobic source consists in transforming the phosphagens, ATP (Adenosine Tri Phosphate) and CP (Creatine Phosphate), without oxygen, into the sarcoplasm of cells.
ATP is the only energy source directly usable by the contractile elements of muscle. CP is a secondary source allowing a quick ATP regeneration. This process is limited by the very small phosphagen reserves.
In an extreme effort, only 50% of ATP and 90% of CP are used.
The phosphagens regeneration is done from oxygen into mitochondrias. So, the aerobic source is important through the oxydative process of muscular cells.