I used to turn off my pump during exercise until a diabetes trainer advised me not to, saying “non-diabetics don’t turn off their pancreas for exercise.” Made sense to me.
If I’m exercising (running or body weight and core strength exercises) and eating before hand, I reduce my bolus by one unit for each hour of exercise.
If I’m going to be exercising more than an hour, I reduce my bolus by 50% an hour ahead of time and keep the bolus low for the duration of my session.
Remember that what you do now with your pump affects your bg two hours from now.
I try to start my sessions a little high and test every 30-40 minutes. Resistance training seems to knock my sugars down more quickly than aerobic exercise and for a longer period.
You might want to try borrowing or buying a book named “The Diabetic Athlete” - author I forget. You can find it on Amazon easily.