During cellular respiration all the energy which is contained in the respiratory substrate is not released all at once, instead it is released in a step-wise manner. The energy is released by a series of slow steps which are controlled and moderated enzymatically. It is synthesized in the chemical energy in the form of ATP. Therefore, the energy release cannot occur directly. The advantage of stepwise release of energy is that each step helps in regulation of the energy. And energy is only released when formed or when required. Energy wastage as heat is avoided and energy is stored. Thus, releasing energy in multiple steps ensures efficient use of energy by the body.