elevated blood sugar in the morning

I am prediabetic, with fasting blood sugar levels in the range 101-108. I generally have dinner at 8:30 PM and exercise for about 30 mins, 10:30-11PM, of sterngth training and walking, before going to sleep from 12:30am-8am. I am not taking any medications.

I found that my blood sugar is around 106-108 after 12 hr fasting in the mornings when  I had exercised the night before.  The blood sugar right after my exervise is about 96.

However, when I don't exercise, and keep pretty much the same diet, the fasting blood sugar is around 101 in the mornings.

I am puzzled as to why the fasting sugar is higher when I exercise. If anything, it should be lower, right? How did it go up from 96 to 108 while I was asleep? Thanks for your help.