What is the normal amount your blood sugar levels fall by when exercising?

Depends!: Depending on meds, your diet, whether you have metabolic syndrome. The average drop also depends on your starting blood glucose. It should not drop below 80! exercise for a longer time turns the body into a machine that burns glucose from stored glycogen, to one that start to use free fatty acids. This maintains adequate glucose levels. Sporting activities should not be punctuated by eating.