I did kickboxing for years and always disconnected pump. You will get different answers and there are different strategies to handle it. Basically, I disconnected for comfort purposes and kind of for psychological purposes- it felt good to just be FREE for an hour.
What I would do is:
tested right before class and based on my bloodsugar did several things=
I figured out that a rigorous class usually dropped my sugar about 75-100 points- now yours would be different based on how hard you exercise, age, weight, etc.....
So I would always test right before class and based upon my sliding scale and what my bloodsugar was before exercise would use different stategies like these.
1) did nothing if my sugar was like 180 (your'e sliding scale would be different than mine) and always had glucose tabs handy next to my towel and water and might pop one halfway through the class
2) if it was really high like over 225 I might actually give myself a very very little amount of insulin like a third of the amount I would normally give to correct
3) and if I was lower than like 150 I would pop a couple of glucose tablets before class.
These are just some general rules I had and of course subject to variations. Because kickboxing can be so vigorous, disconnecting was ok for an hour. But some athletes do not like to disconnect for exercise before later sometimes there can be a lag time of a high bloodsugar from not getting your basal amount.
Basically, it is something you just have to figure out with trial and error- but i was able to figure out a routine that worked pretty well maybe 85% of the time and then sometimes it just didn't work well- but that is how diabetes goes!!!
I rarely do kickboxing anymore because of joints, but do alot of spinning and I have a whole other strategy for that and keep my pump on because it is comfortable and not bothersome.
Have fun! kickboxing is sooo much fun- most of the time I was able to forget I was even a diabetic because I was having so much fun and the intensity of it all.