oxygen debt

Oxygen debt refers to the temporary shortfall of oxygen in your muscles during intense activity. When you exercise vigorously, your muscles need more oxygen than your body can supply immediately. To keep going, your body switches to anaerobic energy production, which doesn't require oxygen but produces waste products like lactic acid. After stopping exercise, your body works to restore oxygen levels, remove lactic acid, and repair tissues. This process is called repaying the oxygen debt. Essentially, oxygen debt is the extra oxygen your body needs later to recover from strenuous effort and return to normal.