Why does Lactic Acid build up in muscles?
Lactic acid accumulates when circumstances-such as a sprint-require the body to produce energy faster than it can deliver oxygen to working muscles. The body prefers to generate most of its energy using aerobic methods, meaning with oxygen; during strenuous exercise, we breathe faster to bring in more air. Some circumstances, however-such as when we sprint or lift heavy weights-require that our bodies produce energy faster than they can deliver adequate oxygen. As a result, the tissues generate energy anaerobically, by breaking down glucose into a substance called pyruvate. When the body has plenty of oxygen, pyruvate is shuttled to an aerobic pathway to be further broken down for more energy. But when oxygen is limited, the body temporarily converts pyruvate into a substance called lactate, which lets glucose breakdown-and thus energy production-carry on. The muscle cells can sustain anaerobic energy production for one to three minutes, during which time lactate can accumulate to high
