Diabetes and exercise don't always mix well. While yes, exercise does wonders for the body and can provide significant help in managing blood sugar levels, the unpredictability when the two are mixed is enough to drive anyone crazy.
Just this morning, Dylan started a week of intensive swimming lessons. 45 minutes of near non-stop lengths, practicing all strokes. The only breaks to the lengths are to tread water. I literally has no idea how his blood sugar was going to react but I (perhaps stupidly) tried to base my estimate of previous experience. Ya - anyone with type 1 diabetes or who cares for someone with type 1 knows very well that what works one day does NOT necessarily work the next. But you have to start somewhere, right?
A year and a half when we took Dylan to Mexico for 10 days, we balanced exercise (swimming) with insulin pretty well. Awesomely well, in fact. Turns out with Dyl at that time, that the glucose he was using, via energy he was exerting in the pool, almost perfectly balanced the increase in his blood sugar levels while being disconnected from his pump. Basically, this means he went pumpless for most of the day, every day, and the effects on his blood sugar were minimal. He'd wake up in the morning, test, bolus and eat breakfast, and remove his pump. He'd swim from 9:00 to about noon, test, put the pump back on to bolus for lunch, remove it again, and swim from 12:30 to 4:30 or so. Then he'd resume wearing his pump until the next morning. Seems crazy, yes, but it worked for him because he was so active in the water.
So fast forward 20 months, and add about 25 pounds in body weight. Pre-pool test revealed a bg of 8.1 mmol/l (145.8mg/dl). He wore his pump right up until the climbed into the pool. We didn't run any temp basal rates in the hour or two prior to the lessons, and he didn't have any extra carbs. Did I expect the same results as in Mexico? No. I expected a low, and I was worried because Dylan's telltale warning sign of a low is what he has termed "weak-knees," meaning that his legs feel like they're going to give out at the knees. Of course, in the water he wouldn't feel that because he wasn't standing. I stayed in the viewing area the whole time, armed with dex tabs in the off chance he started to feel low.
Post-swimming test result? 12.9 mmol/l (232.2 mg/dl). Go figure...