Oxygen debt occurs when muscles are exerted beyond the ability of the body to supply oxygen to muscle fibers fast enough, according to BrianMac Sports Coach. Such exertion must be very strenuous before oxygen debt occurs.
Oxygen debt is the term for the oxygen that must be resupplied to the body to return it to a normal state after extreme exertion, according to BrianMac Sports Coach. After such exertion, the body must completely catabolize lactic acid into carbon dioxide and water, and extra oxygen may be required for the catabolic process and the restoration of oxygen that was borrowed from myoglobin, hemoglobin, air in the lungs and bodily fluids. The maximum rate of oxygen an individual can consume during catabolism is his maximal oxygen uptake, and it can be affected by sex, age and body size.
Additionally, intense training may provide an individual with a maximal oxygen uptake double that of average people, though genetics and extreme training may also be factors. Full recovery from oxygen debt can take 24 hours or longer, after which the body returns to the oxygen uptake it had before exercise began. A high carbohydrate diet may help in the recovery of glycogen lost during the oxygen debt, according to BrianMac Sports Coach.