Oxygen Debt - Test Yourself Quiz

When you have a short intense burst of exercise such as sprinting you generate energy for this anaerobically or without oxygen. When you stop exercising you are still breathing heavily. This is your body taking in extra oxygen to 'repay' the oxygen debt. Well, that is the simple solution but there is a little more to it if you want to look a bit deeper....learn more

What does the term "oxygen debt" mean?
One definition of oxygen debt is "where the demand for oxygen is greater than the supply". In practical terms this means that your body is working hard, you are breathing in a lot of oxygen but you cannot absorb enough to cope with the level of activity. If this happens, your body is mainly utilising the anaerobic energy system and as a result, lactic acid builds up as an undesirable waste product. This system can only be sustained for about 60 seconds (depending on the individual) before severe fatigue sets in and you would have to take time to recover. The amount of oxygen "owed" to the body in order to recover is called the oxygen debt.

An example of this is if you run a hard race like the 400 metres where you start and finish using mainly the anaerobic systems. Soreness and fatigue sets into the muscles and you need to "repay" your body with oxygen after the race in order to recover.

Other examples in Sport:
Bobby was a rugby prop forward. In a game he worked hard for about 1 minute where he did a series of things including running at top speed picking up the ball, side stepping players, being tackled, getting back up and passing to his team mate Akbar. He was working at about 90% of his maximum intensity.

Physiologically speaking, during this time, he used up in order to produce energy. His body was demanding oxygen all the time, but he could not get enough into his . MOST IMPORTANTLY, he could not get enough through his lung walls and into his stream. So, instead of trying to continue using oxygen (aerobic system), his body "switched" to using mainly the ANAEROBIC energy system which did not require as much . However, this came at a price......

In order to "pay back the oxygen debt", his body did the following:
1) His rate rose to enable more oxygen to get to his lungs.
2) His heart rate rose to enable the oxygen from his lungs to quickly move into the blood stream and be pumped to his where it could be used to help break down the lactic acid which had built up.
3) His muscles became sore and tired, which stopped his body from working at that level until he had recovered. This is the body's own system which stops damage occurring.