I am 48 and obese. BMI 34.5. After a good late night exercise next day morning blood sugar levels at in the range of 5.1 to 5.8.
On the day there is no exercise at night the next morning blood sugar level range between 6.2 to 7.1.
My understanding is that one of the major contributing factors to Type 2 is insulin resistance. Exercise is known to affect our insulin sensitivity for around 16 hours or so afterwards. So, that would be my theory on why your fasting level is higher the day after you've missed your exercise.