# Why do I need to eat during exercise if my BS is high?



## sololite (Feb 20, 2018)

As my diabetes is switching from LADA to type 1 I am getting very interested in the whole subject of exercise and nutrition in an effort to find an optimal plan for me. I do a lot of cycling mixed in with walking. My blood sugar is always generally high but I don't understand why if I have all this sugar running around my veins do I sometimes feel weak/feint during a long cycle ride and this is alleviated by eating an energy bar. I am betting this a really obvious question but I am struggling with information overload and would love someone who knows to give me a quick explanation please.

thank you!


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## Matt Cycle (Feb 20, 2018)

Hi.  I presume as a LADA you're on insulin.  When you say your blood sugar is always high what sort of levels are you talking about?  How far are you cycling before you feel weak and what are your levels like at that stage?  I know if I'm cycling with high levels - anything over about 13 or 14 then I start to feel sluggish with heavy legs.  An energy bar at that stage for me would make it worse and unless I thought it was going to come down then a correction of at least 1u would be in order.


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## sololite (Feb 20, 2018)

Hi Matt, thanks for taking an interest. I am just on basal insulin at the moment (10 units Levemir at night). I am usually around 11 mmol an hour or so after breakfast which is usually when I get a longer ride in. My analysis isn't very scientific but I start to fade around 25 miles at moderate pace (12mph ish for me - well I am 58!). Until recently I could do my 30 mile loop without anything to eat but recently felt feint towards the end. I feel similar towards the end of a 10 mile walk. I know I am no where near a hypo but eating something always seems to get me going again. I imagine the food turns into sugar and is absorbed by my muscles but why don't they use the sugar that presumably is already in the 'system'? regards, Chris


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## Matt Cycle (Feb 20, 2018)

Hi Chris.  Do you know what levels you're at at 25 miles or are they 11 the whole way through?  11 is not massively raised - although not ideal I wouldn't be overly worried on a ride if mine hovered around the 11 mark.  The idea of basal insulin is that it deals with the background glucose in the body produced by the liver.  A possible reason could be as cells require insulin to let glucose in (the analogy is usually insulin is the key to open the cell door to let glucose in ) if there is not enough insulin then your muscle cells will still require glucose (especially on a long bike ride or walk) so having something to eat may be stimulating your remaining working pancreatic beta cells to release a bigger dose of insulin to deal with it.  Your body must still be producing a fair bit of insulin to survive on 10u Levemir but you may wish to speak to your medical team about your levels and doses.

Well done as 30 miles at a 12mph average at any age is not to be sniffed at.  Keep pedalling.


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## trophywench (Feb 21, 2018)

I'd put money on it that you actually are getting what is termed a 'false hypo' after X amount of  exercise.  This happens when the BG has been elevated for long enough for the person's body and brain, to get used to having the higher BG - and get into the habit of perceiving 11 as normal.  Hence when you reduce your BG (which the exercise will do) the brain doesn't like it and falsely perceives it as dangerous - so gives exactly the same symptoms as it does to me & Matt and would to anyone with well controlled BGs and even non-diabetic, when our BG drops below the magic 4.0 - ie a REAL hypo !

In fact at these higher levels there is no imminent danger to your life, not like there is below 4.0 - but the only way to stop the symptoms is to feed yourself with a bit more glucose - you'll absolutely have to do that halfway through a bike-ride in order to get back.

To be honest, you'd do better right now, to not go as far in one go until you can get a better insulin regimen established (more Levemir - two jabs of that a day are better for 24hr coverage and a bolus insulin before food) and then reintroduce longer exercise sessions gradually, adjusting doses as you go until you get it right again.  If you just carry on regardless then the only person who'll suffer is you, I feel.

It is awkward cos until your errant pancreas has finally finished lobbing unspecified amounts of your own insulin into your body as and when it happens to decide it will - it's so unpredictable it's a bit like wading through quicksand I'm afraid, so I do feel for you!

Let's see what other folk think, anyway.


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## sololite (Feb 22, 2018)

Thanks Matt and Trophy Wench. I just got my latest HB1ac results back and met with my lovely diabetic nurse yesterday who confirmed my gut feel that my profile is changing. She is not concerned that I need to have a snack bar to get me through the ride and feels it's consistent with my BS control being relatively poor at the moment. We talked about the split Levemir dose but have decided to use Novorapid insulin for meals where I have more than I have 50g of carbohydrate in the evening. We are going to try this for a few weeks and then I am going to try Freestyle Libre on a trial. I knew this moment would come one day. As I build back up to the longer distances 50-70-100 miles for the Summer it's going to be interesting to see how my body reacts and how to fuel it. Strange to say but getting diabetes just as I hit retirement was one of the best things that could have happened in terms of igniting my love of cycling and making exercise a big part of my week. I recommend it to anyone thinking of having a go. regards, Chris


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## trophywench (Feb 23, 2018)

Good - once the pesky pancreas has stopped lobbing it's four pennorth in, as and when you can make proper decions about it all - you'll be fine again but now, it's fire-fighting,  grrr.

Enjoy the ride(s) !


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## BigMalc (Feb 27, 2018)

I dont do alot of cycling, but do run a reasonable amount and the difference between a gentle jog and a hard session is quite dramativ for BS levels.  Gentle job means lower BG levels, but hard session for me leads to much higher BS levels for the next two to three hours.  I wish I could find the right balance between losing weight, gaining speed, controlled BS levels and eating, but what is life without a challenge!  (T2 but MDI insulin)


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## sololite (Feb 27, 2018)

BigMalc said:


> I dont do alot of cycling, but do run a reasonable amount and the difference between a gentle jog and a hard session is quite dramativ for BS levels.  Gentle job means lower BG levels, but hard session for me leads to much higher BS levels for the next two to three hours.  I wish I could find the right balance between losing weight, gaining speed, controlled BS levels and eating, but what is life without a challenge!  (T2 but MDI insulin)


Thanks BigMalc. It's all so confusing isn't it. I wonder if someone has modelled how all the various components of our endocrine systems work with respect to carbs, exercise and all the other factors. I'd be able to understand it all so much better of I had a nice diagram


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