How long after exercise would you expect to see a drop in blood sugar? I’m fairly recently diagnosed and getting the hang of carb counting, adjusting my insulin dose etc. This morning I decided to risk a bit of gentle exercise (I’d been nervous of throwing that into the mix!) and went swimming. I tested when I got out of the pool at 9am and all was fine. Went home, ate the same things I usually have (30g carbs) and had insulin as usual. Then when I tested at lunchtime my reading was 3.3! Could a little bit of gentle exercise have that effect over 4 hours later? I wouldn’t have thought so but I can’t see what else caused the hypo.