Exercise

During exercise the body needs a lot of energy for contraction

- Aerobic respiration increases, so breathing rate and breathing volume increases

- The heart rate also increases to pump the oxygenated blood around the body

When not enough oxygen is supplied, you switch to anaerobic respiration

glucose → lactic acid + energy

- The lactic acid causes muscle fatigue, causing the muscles to not contract efficiently

- The body then removes the lactic acid from the muscles, which causes oxygen debt

- The lactic acid is transported out of the muscles by the blood

- The lactic acid is then taken to the liver and converted back to glucose, which requires oxygen

The oxygen debt is the amount of extra oxygen the body needs after exercise to deal with the lactic acid