Can someone explain...

Hi,

Your right, you shouldn't exercise if your BG's are over 13mmol ESPECIALLY if you have ketones present..

I was told this is because..

If your BG is 13mmol it could mean you aren't getting enough insulin..

If your not getting enough insulin your body breaks down fat cells for energy and produces ketones...

If you exercise on top of this your body needs more energy due to the increase in activity..

But again with not enough insulin, your body will again break down more fat to fuel the body producing even more ketones..

And ketones + Ketones = a very poorly person!

Hope this explains simply for you

It isn't just ketones.....it is also the case that at that point (around 13 mmol/l) your Bg levels can also start to climb and go even higher. Most exercise usually reduces Bg levels.......but as pointed out in the thread you refer to they can go higher ! Add medium/highKetones to that and you could be in trouble ........

These are the commonly given levels
Lower than 100 mg/dL (5.6 mmol/L). Your blood sugar may be too low so eat a small carbohydrate-containing snack.
100 to 250 mg/dL (5.6 to 13.9 mmol/L). Fine
250 mg/dL (13.9 mmol/L) or higher. Caution Test for ketones, may not be enough circulating insulin
300 mg/dL (16.7 mmol/L) or higher. Quite probably too little insulin, don't exercise until lower.

you can see the levels are mg/dl derived and are rounded figures.
(I expect a similar chart from a country that uses mmols would actually read lower than 5.5mmol/l, 5.5-14mmol/l, 14mmol/l or higher, 17mmol/l or higher)

Of course the BG level may just be inflated due to how recently you ate and that it has not come back down again, or you may deliberately have adjusted the last insulin dose in order to allow for the up coming exercise. I would be unlikely to be in the mood for doing anything energetic if I was in the range approaching the 16's, but around 13 and a bit would have been a common target for me before starting any exercise.

It also depends on what exercise you are about to do and for how long and what intensity.

Here's a link from an NHS website regarding the principles when exercising taken from the DAFNE Handbook. (Insulin dose adjustment for Physical Exercise) The levels quoted are what is advised in the UK by most of the HCP's and websites although a little leeway can be given if you know exactly what you are doing. Levels over 13 mmol/l are the time when you need to check for Ketones.......

http://medweb.bham.ac.uk/easdec/prevent ... ercise.htm

Scroll down the page to the chart which gives the levels and advice as to what to do........

If your diabetes is poorly controlled or your blood glucose is raised (e.g. over 13mmol/l) prior to exercise, the exercise probably will not lower your blood glucose level significantly. It is likely that your blood glucose level will rise....this is because you probably do not have enough insulin circulating in your body. Consider injecting an extra dose of quick-acting insulin to reduce the level before your exercise, and always check for ketones.

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If ketones are present in your urine you need to avoid exercise until your blood level is below 13mol/l. Follow the advice given for positive ketone tests.

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UK sourced.

This site is just the best! We live overseas where there is Very limited resources available to diabetic patients so this sort of information is so important to know. My son loves playing sports. If I hadn't know this info I would have just let him play thinking it would bring down his BG levels if it was on the high side. But it all makes sense to me after reading the replies - that is not to exercise! I will be discussing this further when I speak with our doctor this weekend.
Thanks!

spideog said:

Of course the BG level may just be inflated due to how recently you ate and that it has not come back down again, or you may deliberately have adjusted the last insulin dose in order to allow for the up coming exercise. I would be unlikely to be in the mood for doing anything energetic if I was in the range approaching the 16's, but around 13 and a bit would have been a common target for me before starting any exercise.

It also depends on what exercise you are about to do and for how long and what intensity.

Click to expand...

all very good advice. Agree 100%.

I understand all the stuff ebony said (thanks ebony!) but there is one thing I don't understand. When you do exercise and you bg is, say, under 13, your body uses the actual sugar in the blood as its fuel. It doesn't need insulin to do that - it uses insulin to STORE blood sugar for the future. So why does it stop being able to just use up the blood sugar directly once the blood sugar is over 13 or so? Why does it think it needs to start breaking down the fats for fuel?
I know bodies don't 'think' but you know what I mean.