Blood sugar spikes with running

Well, that is interesting! My BG goes down when I walk (not fast), down when I go on my elliptical machine (not too much exertion mind), and up when I do stretching or a small amount of weight lifting.... I have no idea how this works!

Melgar said:

Hi there @Stephie . I'm just going to make a general comment as I'm not on insulin so I'll be mindful what I say. Running or anything that raises my heart rate will increase my blood sugars. Depending on the amount of exertion, my blood sugars can go from my baseline of 6mmol/ls to over 11mmol/ls. I'm fit and lean. If it is a slow jog, my blood sugars will rise, but it will not be a high rise. If I sprint, or hill climb then I will see my blood sugars rise significantly.

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Melgar said:

@LionChild the reason blood sugars rise during strenuous activity, such as weights , resistance training and fast sprints, is your body releases stress hormones which activates a glycogen release. This release 'instructs' your liver to produce glucose and release it into your blood stream. It is a typical fight or flight response. If you are just walking this glycogen release may not be happening so you are burning your blood sugars, hence the drop.

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Thanks Melgar!

@Stephie how far/fast are you running? Some people need to take bolus before running (I've not run much since school and back then was fixed doses and I always ran low, but I do ride a bike and I take bolus to cover the combo of FotF/nerves at the start of long rides - usually not enough though, but I've got a different problem to solve in that the glucose provided by the liver tails off well before the insulin has completely gone away and all the time muscle insulin sensitivity is rising)

I realise you're not keen on doing this, but it might be the only answer (you may well need to eat something fairly immediately after you stop running). I'd be tempted to take e.g. a unit of bolus and see how you go (take snacks, accept you may possibly be forced to bail out, but it is only one unit so can be dealt with pretty easily) and then work up from there.

More posts on running to be found e.g. here: https://forum.diabetes.org.uk/boards/threads/t1-diabetes-and-running.117292/

It depends on the level of exertion on the run, a gentle run will drop me, a fast run will raise me, as mentioned above it's about the stress hormones released during exercise which we need to get our muscles optimised for the duration that affects our BG levels. Another runner once told me that if they go low during a run then they sprint for 5 mins to raise their levels, personally i've not tried it, but sounds rational.

All exercise impacts BG levels, it's just a learning process to see how it affects us and how we can manage it.

Been a while since I was on MDI (so not sure this will help) but I remember Levemir was active for about 22 hours rather than 24.

Would splitting your dose be worth a go - 2 injections split roughly 12 hours apart?

Also worth noting Levemir is being phased out - end of this year, so might be worth looking for an alternative that works better for you for 24 hours (no idea what those choices are though)

CheeseSeaker said:

Would splitting your dose be worth a go - 2 injections split roughly 12 hours apart?

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From the description she's already splitting 9am/9pm.

I doubt it's this though (or rather I doubt adjusting this will fix it, it may make a small difference), the effect of stress hormones on the liver far outweighs any basal effects for me until I'm 5 or 6h into exercise.

Melgar said:

@LionChild the reason blood sugars rise during strenuous activity, such as weights , resistance training and fast sprints, is your body releases stress hormones which activates a glycogen release. This release 'instructs' your liver to produce glucose and release it into your blood stream. It is a typical fight or flight response. If you are just walking this glycogen release may not be happening so you are burning your blood sugars, hence the drop.

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What a complicated disease. T1 started 15 years ago when I was 55, and until this week, my blood sugars would drop when I exercised, particularly if bicycling hard. Now it goes up quickly. I usually like to have it around 8.0 or so when I start out, but after an hour it has hit 15 at the end of the ride and climbs to over 20.