Answer: Due to the body getting up and moving around after a long rest, it needs fuel, like an automobile, to help with body movemment and adding nutrients neeed for blood, muscles, and the bones.
Explanation: For example, if when you get up form a long rest and/or sleep of up to 6-8 hours, there are is not much left of any residual "fuel" from eating dinner the night before as most of it within that time has been assimilated and/or gone through a adsorption process and delivered the nutrients needed for the body to utilize. That is why if you skip breakfast it can be easy to notice symptoms of fatigue, tiredness, even nausea and that is the most extreme as you go through the first part of your day. Therefore, it is wise and of utmost importance to eat a nutrient and protein rich breakfast before a workout or exercise before going to your job or usual activities of the day.