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Sugar levels plummeting post exercise

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This thread is now closed. Please contact Anna DUK, Ieva DUK or everydayupsanddowns if you would like it re-opened.

Rob Oldfield

Well-Known Member
Relationship to Diabetes
Type 1
Hi all,

I had an odd response to some exercise last week. Just wondering whether it's a situation that anyone else recognises?

I've been jogging now for about a year and have managed to get to a position where I can comfortably run 5k. Thinking about how to move on from there I've decided to target doing it faster. Looking around, mostly on youtube, for recommendations on how to do that it seems that best plan is go with a combination of longer runs at a nice easy pace (to build up aerobic capacity), and shorter more intense interval sessions (to get the legs used to going at a faster speed).

The longer sessions I've done a few of and they've been fine - up to 7k at a pace where breathing would allow for conversation. The fun came on Friday late afternoon when I tried my first interval session. The session itself was fine but straight afterwards my levels started going straight down. Had some sugar. And some more. And some more. And some more. Finally managed to get level up from the basement after about two hours. Following that over the evening and Saturday morning levels were continuing to go down (not straight down, more gradual) meaning two wake up calls from the Libre 2. The rest of Saturday was also a bit strange - seemed that both carb and insulin were kicking in quicker than usual.

Fingers crossed it'll be a one off, and obviously next time I do the interval session I'm going to be very careful about ensuring quick access to lots of sugar, but just wondering whether anyone has any advice on how to handle this?
 
Mmmmm - any exercise can easily affect BG for up to 48 hours thereafter - hence if you do this again it should be a good idea to reduce your basal insulin on the day and the day after, if not the next day as well.

Couldn't possibly guess by how much even if I had the same thing, because we're all different. I'm very cautious - so if someone tells me 10% I choose 5% - so I'd start with 5% reduction - but as always, test test test! Hopefully you use Libre!
 
Mmmmm - any exercise can easily affect BG for up to 48 hours thereafter - hence if you do this again it should be a good idea to reduce your basal insulin on the day and the day after, if not the next day as well.

Couldn't possibly guess by how much even if I had the same thing, because we're all different. I'm very cautious - so if someone tells me 10% I choose 5% - so I'd start with 5% reduction - but as always, test test test! Hopefully you use Libre!
Yeah. That's certainly something I could try. Thing is I've been exercising on a regular basis all this year without the need to do that type of reduction - but might be that the higher level of intensity has triggered it.

And yes, extensive use of the Libre is something I'm doing habitually anyway so no change there!

Thanks for the suggestion.
 
I was advised to reduce my basal by 20% after vigorous exercise.
For me, this works for the next 48 hours but it depends what insulin you are using.
Tresiba requires 3 or 4 days to take affect so not much use unless your basal needs remain constant.
 
I was advised to reduce my basal by 20% after vigorous exercise.
For me, this works for the next 48 hours but it depends what insulin you are using.
Tresiba requires 3 or 4 days to take affect so not much use unless your basal needs remain constant.
Interesting. I'm on Novorapid via a pump.

Checking around now it does seem that there are lots of sites with general recommendations but sadly not a great deal of consistency between them. I also can't see anything out there specific for Novorapid.

Thanks for the input.
 
Interesting. I'm on Novorapid via a pump.

Checking around now it does seem that there are lots of sites with general recommendations but sadly not a great deal of consistency between them. I also can't see anything out there specific for Novorapid.

Thanks for the input.
I too am on a pump which makes it much easier to reduce basal.
Most pumps have the option to set a temporary basal.
I chose to set up a new basal pattern which is about 15% lower than my standard pattern but follows the same profile. The reason for the "exercise pattern" is I found the temporary basal is overwritten (it automatically reverts to 100% basal) when I suspend basal or if I change my pump set. Selecting a different basal pattern is not overwritten.
If you run at around the same time, you can set a pattern for running days - I have a climbing pattern.

For me, this approach worked well for NovoRapid and the Fiasp I use now - I just have to remember a change can take an hour to take effect.

Finally, in your checking around, have you come across Runsweet? This is a site for people with Type 1 doing different types of sport. Some stories form elites and some tips for "normals".
 
I too am on a pump which makes it much easier to reduce basal.
Most pumps have the option to set a temporary basal.
I chose to set up a new basal pattern which is about 15% lower than my standard pattern but follows the same profile. The reason for the "exercise pattern" is I found the temporary basal is overwritten (it automatically reverts to 100% basal) when I suspend basal or if I change my pump set. Selecting a different basal pattern is not overwritten.
If you run at around the same time, you can set a pattern for running days - I have a climbing pattern.

For me, this approach worked well for NovoRapid and the Fiasp I use now - I just have to remember a change can take an hour to take effect.

Finally, in your checking around, have you come across Runsweet? This is a site for people with Type 1 doing different types of sport. Some stories form elites and some tips for "normals".
Excellent idea to have an 'exercise pattern'. I've not run into that issue of a temp basal getting overwritten but can certainly see how that could happen so makes sense to do it your way. Not sure whether it's going to be applicable for my easier running days but one to keep an eye on.

I have taken a look at the runsweet site but thought it looked like it wasn't active any more. Tried accessing various things on there but without a lot of success. You'd say it's still worth checking in on?
 
I have taken a look at the runsweet site but thought it looked like it wasn't active any more. Tried accessing various things on there but without a lot of success. You'd say it's still worth checking in on?
I must admit I have not looked at it for a few years.
It used to be a great resource so it would be sad if it has become stagnant.

Sorry, I can't add any more.
 
Runsweet was 'run' by Loughborough Uni (which makes sense cos it's where most senior school Games teachers gained their qualifications; the 'go to' place for same back when I was at senior school in the 1960s - I remember going c.1965 as a spectator one evening to L Tech with the school basketball team!) and the website was active prior to and just after the London Olympics - I always tacitly understood that Steve Redgrave's insulin pump diabetes treatment was overseen/enabled via them, but I guess it's gone the same way as a lot of things, too little money, too few interested experts to man it usefully. Shame.
 
Yeah. That's certainly something I could try. Thing is I've been exercising on a regular basis all this year without the need to do that type of reduction - but might be that the higher level of intensity has triggered it.
I've noticed a pattern when I'm building up through a training programme is that everything is fairly stable then suddenly it's as if things have tipped over a threshold and insulin sensitivity goes through the roof for a few days, often not even in response to a single activity just an overall steady increase in intensity over time. After a few days it settles back to roughly the same level until the next time.
Not sure what the explanation is for these peaks in sensitivity, or if it affects others in the same way, but maybe that's what's happening?
 
I've noticed a pattern when I'm building up through a training programme is that everything is fairly stable then suddenly it's as if things have tipped over a threshold and insulin sensitivity goes through the roof for a few days, often not even in response to a single activity just an overall steady increase in intensity over time. After a few days it settles back to roughly the same level until the next time.
Not sure what the explanation is for these peaks in sensitivity, or if it affects others in the same way, but maybe that's what's happening?
Certainly sounds like something similar. While adjusting basal rates and having some sugar before exercise does make sense to me, it still leaves the question of exactly why my level decided to plunge and not respond to sugar for such a long period unanswered. Guess that, at least in part, we just have to blame the evil diabetes fairies (while making sure we have emergency sugar to hand)!
 
Runsweet was 'run' by Loughborough Uni (which makes sense cos it's where most senior school Games teachers gained their qualifications; the 'go to' place for same back when I was at senior school in the 1960s - I remember going c.1965 as a spectator one evening to L Tech with the school basketball team!) and the website was active prior to and just after the London Olympics - I always tacitly understood that Steve Redgrave's insulin pump diabetes treatment was overseen/enabled via them, but I guess it's gone the same way as a lot of things, too little money, too few interested experts to man it usefully. Shame.
It's definitely a shame - would be a fabulous resource to have in place. I did actually find another similarish site that was recommended by @everydayupsanddowns on here back in 2018 - https://excarbs.sansum.org/

Edit: 'Recommended' is the wrong word. Just in case it's actually a hopeless site that should really be 'Mentioned'.
 
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Edit: 'Recommended' is the wrong word. Just in case it's actually a hopeless site that should really be 'Mentioned'.

These days I generally suggest Extod, another exercise/T1D resource set up by Drs / Consultants who specialise in the field.

 
These days I generally suggest Extod, another exercise/T1D resource set up by Drs / Consultants who specialise in the field.

Very swish website and the credentials on the 'About' page look extremely good - but sadly it looks like a bit of a work in progress. The patient advice section, for example, just has one article as below.

Am I missing something?

1653419305864.png
 
Very swish website and the credentials on the 'About' page look extremely good - but sadly it looks like a bit of a work in progress. The patient advice section, for example, just has one article as below.

Am I missing something?

View attachment 21084

Ah that’s a shame. Yes as you say, something of a work in progress?

I am aware of it from presentations at conferences (so perhaps there are more resources in the HCP side to which we don’t have access?).

Some of the research papers seem to be openly available, which may have something, including this which suggests a T1 education programme for exercise may still be in development

 
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Ah that’s a shame. Yes as you say, something of a work in progress?

I am aware of it from presentations at conferences (so perhaps there are more resources in the HCP side to which we don’t have access?).

Some of the research papers seem to be openly available, which may have something, including this which suggests a T1 education programme for exercise may still be in development

Interesting link. That does frame the site in a different way and clearly we can't expect it to be fully functional. I did actually ping an email off to one of the people behind the site (and the article) yesterday - Prof Rob Andrews - to ask about the possibility of getting involved in any research and, in more general terms, about the site itself. Not had anything back so far.

It does seem that a central site to advise on all levels of exercise - ideally all the way from best way to get out walking in the park up to ultramarathons - would make sense.
 
Hi Rob, I've been running for the last 10 years, like you I started steadily building up to 5K, then progressed to longer distances. Have done 3 full marathons, about 30 half marathons and loads more 10K and 5K runs. We're all different, but my strategy is as follows : 5K - just make sure glucose reading is ok, if slightly low a couple of jelly babies before i set off. 10K - couple of jelly babies and a biscuit before starting. Half marathon - same again before starting, and another couple of JBs after each 5K. Full marathon - same again at start, Camelbak full of flat full sugar coca cola to sip on way round, and two JBs after each 5K. For half marathon and above I reduce my basal by half the day before and the day of the run. Have Freestyle Libre 2 linked to my phone, so get low or high reading alarms as I'm on the run and adjust my jelly baby intake accordingly. And of course take water in at every water station. Works for me but as I said we're all different, you'll find out what works for you through trial and error. Good luck!
 
Thanks @johntheterrier

Agree that we're all different and I've been trying various different things - and happily not had another episode as I described back in the original post. Usage of JBs I'm very aware of - they've been my go to fuel for long bike rides - so was definitely thinking of trying them while running.
 
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