Oxygen Debt Theory

Oxygen Debt Theory explains how the body responds after intense exercise. When you engage in strenuous activity, your muscles work so hard that they temporarily produce energy without enough oxygen, leading to the buildup of waste products like lactic acid. To recover, your body needs extra oxygen to break down these wastes and restore normal function. This "debt" is repaid during rest, often through rapid, deeper breathing — called excess post-exercise oxygen consumption (EPOC). Essentially, oxygen debt reflects the extra oxygen your body requires after exercise to recover and return to resting conditions.