What should blood sugar be before exercising?

Samantha_84

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Hello!

I am a type 1 diabetic on insulin - Novorapid and Lantus - I have been an insulin dependent diabetic since I was 2 years old and i'm now 26 (whee does the time go?!). Over the past few years the weight has been creeping on and after a GP visit a few weeks ago, I've been told I have to shift 3 stone of weight. Help.

So i've joined a gym and i'm actually really enjoying it (might not be saying that in a few weeks time!). I just need a bit of advice on blood sugar levels before exercising. What level should my blood sugars be at before going to the gym??

At the minute they would be sitting around weight, but i've done a lot of reading around blood sugar levels being too high which then makes it impossible to lose weight.

Help!

Sam xx
 

janabelle

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Hi Samantha,
Firstly well done for joining a gym, You're a braver woman than me, those places terrify me!
I don't think anyone can really advise you on an exact level, but I was told many years ago that it was not safe to excercise if my BG was over 15, others say 12. With high BG levels your body is more dehydrated to start with.
It's a very personal thing and will depend on your medicaton and what you have eaten, even a few hours before the excercise taken, so you'll have to take your meter with you and check during your sessions, until you find what suits you I'm afraid.
My son and I sometimes go running, and my BG can plummit to the 3s after a 1/2 hour jog, when it's been 8-9 beforehand. Consequently I now have a glass of orange juice, which prevents it most of the time :? .
Also do a google search for "Lantus weight gain" and you'll see your not alone! Some of your weight gain may be down to fluid retantion.
take care
Jus :)
 

Samantha_84

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I do have to hold my hands up here and admit that I was completely and utterly terrified the first time I went into the gym and I got a bit teary when I was standing in the changing rooms! The thought of going out in front of everybody and exercising was terrifying! But i'm so glad I perservered and stuck with it because I do actually enjoy it now!

I'll test my blood before, after and during my session and see how quickly it falls. I read on the internet that if your blood is under 5mmol it's too low to exercise, if it's between 5mmol and 12mmol your good to go, and if it's over 13mmol it's dangerous and runs the risk of ketoacidosis :shock:. Then again, I pulled this off an internet site so now idea if it's valid or not! Will maybe try and get my blood to 8mmol and start from there and see how we get on!

Thank you for the advice on the lantus, i'll go and search for the info now!
 

hazyclaire

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If you do work out the answer to this one you're doing better than me! I've been going the gym a few nights a week for the last couple of years. I will always have a banana or something about an hour beforehand, but the effects of exercising on my sugar levels seems to be totally random - even though I do the exact same routine every time I go! Some days I start off on 8 and finish up at 16, other days I start off at 12 and end up at 3! The last few weeks (since changing to a new gym where the changing room is further away) I have started to take my meter and a tube of hypogel into the gym with me, typically I haven't had a single hypo since I started doing this and my blood sugars have remained perfect. It is a total mystery to me!
 

SophiaW

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In my experience with our daughter it greatly depends on when last she took an insulin injection (Novorapid). If Jess does exercise within 2 to 2.5 hours of injecting we aim for her readings to be higher than we would if she was doing exercise at around 3-4 hours after injecting. If she exercises when her insulin is at peak effectiveness (1.5 to 2.5 hours of injecting) then her blood sugars drop much more dramatically than at times when the insulin is beginning to loose it's full effectiveness. We've found the best way of coping with this is by keeping exercise to a routine. For example she does swimming at a specific time each day so that we know how to predict her blood sugars better.

Everyone is different and different types of exercise can have a different effect on your blood sugars too. For example Jess has a much bigger blood sugar drop with swimming than what she experiences with PE at school. Cross country caused a much bigger drop than with playing netball or tennis. I guess the best way is to experiment and see how things work for you and if at all possible keep to some sort of routine to make it easier to predict. Initially whilst you're learning how things affect you do lots of testing.

Good luck with the gym :)
 

noblehead

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Depending upon the exercise, duration and time of previous meal/insulin dose, I try to keep my bg levels around 6-7mmol beforehand and take fast-acting glucose as a precaution. Should I eat and then exercise within the hour I will reduce my insulin dose by a third to compensate, but if it is 2 or more hours since my last meal I usually find my bg remains pretty stable with only a small fluctuation occasionally.

The only way of knowing is by experimenting and testing......good luck!

Nigel
 

Samantha_84

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9
Thanks for the replies guys. I am getting the vibe that maybe I should wait for around two hours after eating and injecting before heading off to the gym. Nigel I will try and aim for my blood sugar to be around 6mmol and go from there.

Sophia W - thanks for the luck, sometimes I need it when I can't be bothered going to the gym!! As you say, I will just have to see what exercise works for me and what doesn't.

Sam xx