I have noticed in the past that if my bg reading is high, even just 15 minutes of brisk marching through the house with knees raised high and arm circles/swings will drop it 30-40 points. So yes, exercise is a def help. After that supper meal when the numbers were so high, I was sitting watching a movie for 2 hours.
Well, actually you need to throw the glute max in on that since it is the single largest muscle on its own....and will be very well used in the lower body sprint training. Interesting thing is its hardly used in the walking gait, but really comes into its own when we run.