Once you’ve eaten a meal or snack, allow between one and four hours to pass before you start exercising. Your body needs time to digest. The amount of time will depend on the amount of food you've eaten.
If it's an average meal, eating around two to three hours before you exercise works well. If you have only an hour or so before you exercise, then aim for a meal or snack that is rich in carbohydrate, low in fat and moderate in protein, such as porridge made with low-fat milk or a wholegrain sandwich or bagel with chicken and salad. Too much protein or fat will slow down the movement of foods from the stomach, and will make you feel uncomfortable.
Food and drink also plays a part in recovering effectively from training. Good recovery is crucial to prevent a midweek slump in energy levels, and to aid muscle growth and repair. If you are training more than once a day and you have fewer than eight hours between sessions, aim to have a carbohydrate- and protein-rich food or drink within 30 to 60 minutes of finishing your first session. If you are training less than this, or with more time to recover, just eat as soon as you can afterwards.