When you are training, your body is under stress to provide the energy necessary to perform the task at hand.
Metabolic mobilization can increase 10-fold just from a single exercise stressor.
In other words, exercise requires a lot of fuel!
The more intense the exercise is, the more fuel you need to sustain your energy levels.
Fuel can be stored in your muscle as glycogen, but also transported in the blood as glucose.
Glucose either comes from the food you just ate or from your liver where it was released to help aid in providing the necessary energy for exercise.
And guess where glycogen and glucose predominantly come from?
This is why having post workout carbs can be extremely helpful for energy restoration.
Just like protein is broken down and necessitates the consumption of post-workout protein, glucose is used during training and needs to be replenished.