You need to think of your body as a machine. In order to function, it needs fuel in the way of food! This is especially important after a night of fasting or a long break since your last meal. Without this fuel, your body is unable to perform to its optimal level and you lose some of the training benefits you might otherwise gain, not to mention you might feel light-headed and nauseous.
If you are in a hurry, taking in some easily digestible food or drink – like a banana, bagel or smoothie – can make all the difference between a productive session and a fatigue-filled session.