How much time should have between breakfast and the start of training? Before training it is essential to give the body a chance to digest and absorb nutrients. Generally, it is advisable to wait at least two hours before starting to do sports. This way, the body will be able to direct a good part of the blood flow towards the muscles and not towards the organs involved in digestion. The amount and type of food also affect the wait that must elapse between the meal and training.