Levels upped

Yes. according to the Krebs Cycle, when you stop major activity, the glucose in your blood gets stored locally in the muscle instead of being used for movement. When you wake it does not take much to fill the blood with glucose in readiness for exercise because it is already there ready, so the liver is possibly anticipating a higher demand like it does wth the Dawn Phenomenon. so you have charged up the battery by sleeping, and waking has to kick start the machine again.