It is an unusual fact that blood glucose levels go up as we do strenuous exercise.
Whereas just walking will lower your blood glucose levels.
That's just the way the body works to make sure you have enough glucose to help you through the exercise. It's called a liver dump, you also could get this in the mornings to prepare for the day. It's called the dawn phenomenon.
You will normalize shortly after, unless you use glucose to recover, I suggest simple water to rehydrate yourself. It works!