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Managing exercise and insulin

Fern Hopper said:
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?
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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).
 
 
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.
 
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.
 
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.
 
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
 
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...
www.diabettech.com
 
I am regularly exercising mainly riding these days and at a zone 2 level 130 to 140 bpm, bs drops dramatically.
I need to start with some fruit prior to ride and then take a gatorade mix in one of my bottles and the other bottle will have water.

Always ride with a back pack with more food and sugar. I watch my bg on my cgm while riding and when I hit 6 I know I need more sugar.

Also something to note is that food will not be absorbed as quick when exercising the body is not concentrating on so di don't use food to increase bg fast.

End of ride the first thing I do is a small bolus of insulin to offset the end of exercise spike which happens everytime.
 
Have you considered reducing your basal insulin so you don't need to take so much food? It's a balancing act though as you do want a declining BG level while riding to ensure you can eat something but just not too much.

Nai nai said:
Also something to note is that food will not be absorbed as quick when exercising the body is not concentrating on so di don't use food to increase bg fast.
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+1 so if eating slower acting carbs I eat them at a higher BG level and if am really dropping will treat with something fast acting.

This delay is the thing that might cause my BG level to spike after exercise if I have eaten something close to the end of a ride. I don't get post-exercise spikes otherwise.
 
Re. T.1 & exercise, here are some thoughts of mine, for what they're worth...

T.1 for 55 years and counting, late adopter to FreeStyle Libre2, am on waiting list for pump...

Am a p/t Flamenco dance teacher, choreographer, perforner and theatre director, and it's very erratic lifestyle - some days 8-10hrs full-on teaching / rehearsing, other days sat on my bum all day in front of a computer doing admin & paperwork - so always a challenge re. balancing BG / exercise / carb counting etc.

- Luckily the Libre 2 Alerts - when BG is either too high or too low - are loud enough and audible over the crash of class-full ofFlamenco dance footwork! My students all know that they'll be given an exercise or some steps to practise while their teacher either discreetly injects or munches on her 4 'medicinal' Jelly babies!

- a good tip I was given by a Diabetes Nurse a decade ago was: after a busy and ENERGETIC day, DECREASE the evening dose of long-actihg insulin by 0.5u or 1u, to avoid delayed &/or night-time Hypos. This has worked very well for me and ensured fairly good first-thing-in-the-morning BG levels.

Show & performance are anothe challenge: it's full-on energy-wise so I risk running Low, BUT then nerves and adrenaline kick the BG levels sky high...GGGRRRRR !!!....
- I test before, aim to run a little bit High (8-10) to avoid Hypo,
- have 'emergency' Jelly Babies on stand-by in the 'wings' (wht=ether it be a stage, a school hall, a Spanish restaurant or a Care Home!),
- test at interval and/or after show - BUT don't react immdiately: I try to leave it another 30mins or so to be sure of BG trajectory up or down...
- all rather imperfect, but I've come to accept that my T.1 control risks being out-of-whack on those occasions.

....truth be told, I loathe all the faff that T.1 control requires - I am what was once termed a 'brittle diabetic; at the darkest of times, I have felt like someone held hostage for the rest of her life by a threatening kidnapper that whispers daily over my shoulder 'I'll let you live, but only on these T.1 Diabetes self-care conditions, and if you don't follow these conditions, then I will kill you in instalements: you'll lose your sight first, then your feet, then your kidneys..."),

BUT I actually love life and I love dance, and Libre2 has been a game-changer, so I plough on!

Your reactions to all the above are welcome, just please be kind and constructive ;-)

Yours fellow T.1 at the T.1 rockface
Danielle
Flamenco Con Gusto = flamenco with pleasure!
 
Hi Danielle

Sound advice. Particularly the bit about adrenaline pushing BG up during a show, and not to react to it immediately. I find the same thing towards the latter part of an hour of badminton and have learnt that by-and-large my BG will come down on it's own.

Also the tip about adjusting background dosing for active days. I have experimented with this with mixed results, and typically halve it after a very active day. However, from my experience I'm not so sure this has the 'immediate' effect for the night, and sometimes wonder if reduced background takes longer to show the effect.

I set my Libre 'low' alert to 4.6 so I get notice to be able to correct with one or more jelly babies.
 
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