I’m riding three to four times a week now, with two of those being long rides of three or more hours. The long rides are usually on weekends, leaving the 1- and 2-hour rides to happen after work. At least two days during the week, I come straight home from the office, change and hit the road. I can usually manage my blood sugars on the bike, and I have even figured out how to avoid the spikes when I return home. But one thing I can’t seem to figure out is what’s happening hours after I stop pedaling.
This is the graph two hours after a 4-hour ride. First time I’ve ever nailed it during and after. Granted, I ate throughout the ride… but still.
I wake up around 1 or 2 a.m. with a severe low any night when I’ve completed an after-work ride. My CGM is blaring at me, and usually, I’m in the 40s or 50s by the time it wakes me up. So a ride at 5:30 or 6:30 p.m. is affecting me as many as 7 or 8 hours later.
After rides, I’m eating a protein-heavy dinner with little-to-no carbohydrates. I’m not eating anything past 9 p.m., and I take very little insulin for dinner — so little in fact, that cutting back isn’t really an option. I’ve also decreased my basal rate for an hour or so when I first go to bed, but it hasn’t made much difference. The only thing I haven’t tried is eating a snack before I go to sleep. I’d rather not have to do that, but it may be my only option to avoid the lows. I understand that happening within a few hours of heavy exercise, but not that long afterward. I guess it’s just one more example of how diabetes really is a science experiment.
What about you? Have you experienced a drop or a spike many hours post-exercise? Or is this something completely normal I’m just now figuring out?
Victoria is riding 105 miles in October as part of the JDRF Ride to Cure Diabetes fundraiser. She’s been training since September 2011. She’s raising funds for her ride which will go to research and research-related education about type 1 diabetes through JDRF. To support her, click here. Regardless of your ability to donate, she’d love to have your prayers for her training and the Ride in October.
Here’s what might be happening. When you ride, you use up a lot of your muscle glycogen, which is basically stored carbohydrate. When you’re done riding, you have to replace that glycogen from somewhere. If you’re not really eating anything with carbs in it, your body has to pull it from somewhere. This could be what’s dragging your BGs down.
Try having 15-30g of complex carbs within 30 minutes of the end of your ride and see if that makes things help. Good luck!
Last year when S had soccer on Wednesday nights (for only an hour) she would run low most of the night and even at her lunch bg check at school the next day she was low 5 straight weeks. I know that doesn’t help you but at least you aren’t alone in this crazy diabetes world and how it reacts to exercise and all
If your exercise is consistent enough (or the results are), can’t you just change your basal pattern to match? Changing it for an hour is not really long enough to affect anything.
But I haven’t ridden in 9 years so I might be wrong