Managing exercise and insulin

[SimonP78]

Parkrun always spikes my BG. Last 2 half marathons I managed with nothing to eat at all. Run many 10k's. Always spikes BG. But riding the bike, particularly for big mileages, less insulin and lots of food. Perhaps I am a cyclist and not a runner?

Is it about duration though with the bike rides (along with a lower intensity so you don't end up with a large glucose dump throughout the event)?

I'm guessing a half-marathon is short enough that it can be run solely on the glycogen contents of the liver + muscles (which may well have been dumped into your blood stream faster than desired due to the higher intensity), though never having run one I could be wrong!

Intensity will be lower on the bike (for a long ride) which prevents the initial spikes (though I can still manage to spike at the start through stress hormones/wrong dose for breakfast) and if you're riding for a long time your liver will run out of glycogen stores - I find somewhere between 1h30 and 3h is the point at which I usually to start eating something (depending on how much of an initial spike there was and how hard I'm riding) - 1h30 does seem quite a short time (for hepatic depletion at a low work-rate), but my guess is that is partly due to residual bolus from breakfast/FotF cover.

I have a diabetic colleague who runs ultras, I must ask him how his BG responds when running different distances (which I assume must mean different intensities).

 

[janetlouise]

I never called myself a runner when I could just run whenever I wanted, I was just someone who went running, however I have been saying "I was a runner" quite a bit. Totally a case of not realising what you have until it is gone. It wasn't really about fitness (though I was fit), it was about head space and getting some time to think. I used to do it to process ideas like "should I make this big financial commitment" or "should I move into that flat" or "I have type 1 diabetes and that is horrifying." So I basically can't do the thing that I usually would do in order to deal with the problem and I didn't really know I was using it like that.

I have tried to go running, I have not been able to do it without feeling really bad. Right now as I sit here I feel like I am just getting over a bout of flu as I have for weeks, and if I run I can only go at half speed and one quarter distance and the feeling gets worse until I get the shakes and have to stop.

If I can only run if I do a bunch of preparation and mental arithmetic and risk feeling bad, then I will just be thinking about those things all the time and it will defeat the purpose of doing it. Looking back I realise that the purpose of running was to be free of day to day cares and spend some time going over things in my head, and if I can't do that then frankly it is totally pointless.

To end on something useful if not positive, anyone who suspects they have this disease needs to see a doctor absolutely immediately because part of my problem is ketoacidosis which has completely torn up any level of fitness I had. Do not delay, I could have had it for WAY less time and been WAY less damaged by it.

 

[EllieM]

So does anyone have any theories on what happened to me today?

Went on what for me was a fairly epic hill walk, 600m elevation (steep up and then relatively gentle down), 5 hours time. Everything was fine (set my pump to exercise mode which meant I ran at 7-8) until we finished the walk and I collapsed into the car for an hour's drive home. My bg proceeded to shoot up to 12 (with no food) and I had to give quite a large correction dose.

Anyone understand the mechanisms here?

 

[In Response]

So does anyone have any theories on what happened to me today?

Went on what for me was a fairly epic hill walk, 600m elevation (steep up and then relatively gentle down), 5 hours time. Everything was fine (set my pump to exercise mode which meant I ran at 7-8) until we finished the walk and I collapsed into the car for an hour's drive home. My bg proceeded to shoot up to 12 (with no food) and I had to give quite a large correction dose.

Anyone understand the mechanisms here?

Only a guess because I am not sure how closed loop works in exercise mode,
ON a non-closed loop, I will set a temporary reduced basal for exercise but due to the speed on my "ultra fast acting" Fiasp, I have to start the temporary basal 30 minutes before the exercise and end it 30 minutes before ending the exercise.
So, my suggestion would be that you had insufficient basal "on board" when you finished your walk which resulted in your BG rising.

My other observation is that you had the same exercise mode for strenuous uphill and gentle downhill whereas your basal needs may have been different.
For example, for me a gentle downhill may have been fine with my normal basal and reducing it may have also resulted in your later high.
It is definitely the case for me that not all exercise is equal when it comes to basal.