My experience is moderate exercise increases levels.
I cycle now but for the first 45 to 60 mins of any training my sugars go up up then I eat glucose tabs 4g at a time for the remaining time. For about 2 hrs after the training I check and eat carbs banana. Apple something without insulin. And I find that after 2-4 hrs I come crashing down with lows. I am able to manage them it's a case of trying it. Keep fast acting with you. When I do less than an hour I do use insulin before training but carb up.
Hope this helps.