I did a search on TU about BG levels rising after exercise. Most were specifically about after high intensity workouts. I get the science behind that, but....
I have been getting slowly into an exercise routine. I walk 20 minutes on a treadmill--about 3/4 mile in 20 minutes, so it is not a strenuous activity.
Until last week, my BG levels would drop 70 points during a 20 minute walk. Last two times(Friday and today) my blood glucose has SOARED. I was 94 when I started this morning and 203 when I finished, 20 minutes later. I had actually delayed my trip to the rec center to get my BG above 70. Same thing last Friday.