Source
r/diabetes•
linernotes

Blood sugar spiking during exercise

Hey pals! I’m coming off of a long illness that made me pretty much couch-ridden. I’m starting back on mild exercise, mainly taking my dog for long walks. We take about 90 minutes, but stop and break. He’s also a giant breed dog, so he’s not keeping a super fast pace.

Unfortunately I’m having ridiculous spikes during and after this exercise, and crashing about 3 hours later. For example, at the start of my walk I was 7.8mmol, and now I’m 15.4. I had 30 grams of carbs beforehand but also doses for it.

I know this is common-ish (maybe not such an extreme spike) but historically I’ve gone low during exercise so I don’t really have the tools to address this.

I’m guessing I should pre-bolus or increase my basal, but how do I figure out how much? Just trial and error?

I’d love any tips!

Edit: I use a T:Slim and a Dexcom G5 :)

Posted Sep 1, 2019, 7:06 PM UTC · edited

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[deleted]•

Are you using an insulin pump? a glocose sensor?

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linernotesOPType 1 T:Slim X2 Dexcom G5•

Ah shoot I’ll add that to the post! T:slim and a G5 :)

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Bobby_keys•

This happens to me every time I do an anaerobic activity, hockey mostly. I can be 5.0, have a snack before my game, and after i'll be high teens. You'd think it'd be the opposite but diabetes is all over the damn place it seems. I try and eat 2 hours before hand, and let my sugars stabilize as much before I get physical. Keep a gatorade on hand in case you do go low. It's just about finding that sweet spot and what works for you. My doctor always said to wait at least an hour after exercise to give any insulin, as your sugars will start to drop naturally.

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linernotesOPType 1 T:Slim X2 Dexcom G5•

Ahh good call re: timing and Gatorade. I have Addison’s, so I keep a sports drink on hand anyway. But I usually buy sugarless so I’ll pick some up with a bit more glucose :)

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the_linguinistT1 (1995) Omnipod/G6•

I find that my body reacts differently to exercise when I'm just starting a routine back vs. when I've been keeping up a routine for a while.

I get this kind of reaction mostly from weight lifting or high-intensity exercise. But since you are just back to exercise this might feel like "high intensity" to your body right now. As you become more acclimated to this level of activity your pattern might change again, so be ready!

If you know that the pattern is a rise during the exercise and a low after, I would stop eating ahead of time and instead have the snack after, maybe 15-20 minutes ahead of when you expect the crash to happen. Since you have a pump, about 2 hours before you start to exercise you can program an increased temp basal for 30-60 minutes or however long your BG tends to stay elevated during exercise. I would start low, maybe 5-10% increase, and see what that gets you. You can also try to anticipate the lower BGs after by doing a reduced temp basal (again with about a 2-hour lead time).

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linernotesOPType 1 T:Slim X2 Dexcom G5•

This is so helpful, thank you!

Edit: especially the note about just starting a routine. I’ll keep an eye on how things change, it’s a useful thing to be aware of!

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diabetes_is_a_bitch•

Short and to the point:

There is a fine line between mild exercise that lowers your BG, and tiring exercise that will prompt your liver to dump glucose as a response from your muscles.

When you cross from one mode to the other is different for every persons personal fitness level, and therefore only answerable by the individual.

The crash you experience 3 hours later is your body raking glucose back into its reservoir to release the next time your muscles give the liver the go ahead to dump it in. Be advised that this crash can happen anywhere from 3-18 hours after tiring exercise.

For the year I was lifting hard, I had to eat 10g of carbs before warmup cardio, and then pre-bolus before hitting the weights, otherwise I would have gone low form the cardio, and high right after lifting.

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