Pyruvic acid (CH3COCO2H) is an alpha-keto acid, of the keto acid group. The anion of pyruvic acid is called pyruvate.
It is created by the body when sugars are metabolised. Provided that sufficient oxygen is available, pyruvic acid is then broken down through the Krebs cycle. If insufficient oxygen is available, the acid is broken down anaerobically, creating lactic acid.