Anaerobic Respiration in Humans: Understanding When and Why

Humans primarily use aerobic respiration, but during intense activity or low oxygen (e.g., sprinting, breath-holding), muscles temporarily switch to anaerobic respiration. This process breaks down glucose without oxygen, producing ATP less efficiently and generating lactic acid as a byproduct. Lactic acid accumulation causes muscle fatigue and soreness.

Once oxygen is restored, the body converts lactic acid back to glucose or other usable fuels, highlighting the importance of recovery after strenuous exercise.