There are two ways to continuously keep providing energy to the muscles in the body. The body uses the aerobic pathway where the glucose is used to make the ATP to provide energy to the muscle cells. If the store of ATP gets reduced, the body triggers homoeostasis mechanism involving the anaerobic pathway. In this pathway, glucose is converted into lactate in the muscles tissues. This lactate is used to make ATP that is used by the muscle cells. This way the body ensures that the supply of energy is maintained throughout the run.