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.

 

[Jaanrobin]

I try to go to the gym 3 or 4 times a week. And yes, it is not always easy for me to manage my glucose levels there.
I always try to avoid long cardio sessions because I always get a low.
1 month ago I got the OmniPod 5 and hell yeah this thing is amazing. I can put it in activity mode and it reduces my basal rate to get me to my target blood sugar of 150mg/dl.

I have been advised by my doctor to put it on activity mode 2 hours before I go to the gym so that I have as little active insulin in my system as possible. I try to have 0 units of active insulin and be a little below my target so that the pump does not give me any insulin. That way I can be sure it is not lower than when I came into the gym.

If I cannot make it with 0 units of active insulin, I put some sugar in my drink to balance it out.
This has worked for me so far.

Before I got the pump, I always carried sugar or juice with me and checked my sugar after every workout.

 

[Paulgn1]

I do Hiit four times a week, my blood sugar normally rises so I'm experimenting with putting a small dose in prior to starting.

 

[Marta776]

I’ve always loved staying active and enjoy hiking and swimming. I recently started incorporating more regular cycling into my routine, and while it's been a challenge to keep my levels in check, it’s so rewarding. I use a CGM to monitor my glucose during long rides and find that planning snacks or breaks has been crucial. It's amazing how we can still push our limits despite the challenges of managing T1

 

[CheeseSeaker]

Interesting article on exercise, loops and insulin - looks like there are companies working on dual-loop systems that can give glucagon and insulin to deal with high and low BGs - that would be another huge step forward.

For now though - looks like unplanned exercise still requires a snack and monitoring.

Exercise, Insulin and Automation. The challenges. | Diabettech - Diabetes and Technology

There are regularly calls in the #WeAreNotWaiting world to incorporate exercise detection into the algorithms that we use, so that end users can minimise hypo risk and not have to worry about unplanned, mild, exercise. This might cover a half hour walk with the dog, a shopping trip or a similar...

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