Why Are Levels Higher After Exercise

[Lesley56]

Checked sugar when I got home, really pleased 6.6, took when I got home after a walk 7.5 ! Anyone know why the increase ?

 

[Juicyj]

Hello @Lesley56 There is a level of variation in accuracy of readings on BG meters, however it could also be down to a release of adrenaline/cortisol from the exercise itself,. However the benefits of exercise far outweigh a minimal difference of less than 1 mmol/l so keep up the good work.

 

[kitedoc]

Yep, it happens to me too.
What my doc says is that with exercise our muscles release stored sugar which they use to do their work.
In non-diabetics that extra sugar's effect on blood sugar is controlled by release of insulin to keep BSLS in normal range.
In diabetics that extra sugar release is not usually accounted for by our insulin so the blood sugar rises.
In my experience BSLs rise more when the exercise has been more vigourous. Foe example my BSL would be 18 mmol/l + after a hectic number of games of squash, but only up say 2 mmoml/l after a slow walk. Adrenaline, released by the pressure of the squash game, was said to be the culprit for the excessive sugar rise as it causes release of sugar from muscles in emergency situations.
The trap though is that some 6 or so hours later the depletion in stored glucose in the muscle leads to a 'recall' from the blood stream. The greater the depletion, e.g. squash vs walk the more sugar was pulled out the the blood.
As a diabetic volunteer on camps for diabetic children/teenagers I saw this first hand. They would come back from a long morning walk, excited and running about. BSLS would be high in all of them. The doctor however had seen this before and she declined to give the children extra short-acting insulin boluses before lunch. They were all told to have big lunches.
Sure enough, before dinner, all had lowish BSLS and some had to eat early to counter hypos.
I decided that moderate, non-hectic exercise was the best form of exercise for me. Provided I got sufficient exercise to help my blood sugars be more stable and improve my heart health what was the point of rocking the boat so much that I was suffering through the swells of high and low sugars?
Edit: Thank you Millennium. The blood sugar rise during exercise comes from the LIVER not the muscles. And adrenaline causes relays of glucose from the liver, both during exercise and during hypos. In hypos glucagon from the pancreas is released and also stimulates glucose release from the liver.

 

[millenium]

Yep, it happens to me too.
What my doc says is that with exercise our muscles release stored sugar which they use to do their work.
In non-diabetics that extra sugar's effect on blood sugar is controlled by release of insulin to keep BSLS in normal range.
In diabetics that extra sugar release is not usually accounted for by our insulin so the blood sugar rises.
In my experience BSLs rise more when the exercise has been more vigourous. Foe example my BSL would be 18 mmol/l + after a hectic number of games of squash, but only up say 2 mmoml/l after a slow walk. Adrenaline, released by the pressure of the squash game, was said to be the culprit for the excessive sugar rise as it causes release of sugar from muscles in emergency situations.
The trap though is that some 6 or so hours later the depletion in stored glucose in the muscle leads to a 'recall' from the blood stream. The greater the depletion, e.g. squash vs walk the more sugar was pulled out the the blood.
As a diabetic volunteer on camps for diabetic children/teenagers I saw this first hand. They would come back from a long morning walk, excited and running about. BSLS would be high in all of them. The doctor however had seen this before and she declined to give the children extra short-acting insulin boluses before lunch. They were all told to have big lunches.
Sure enough, before dinner, all had lowish BSLS and some had to eat early to counter hypos.
I decided that moderate, non-hectic exercise was the best form of exercise for me. Provided I got sufficient exercise to help my blood sugars be more stable and improve my heart health what was the point of rocking the boat so much that I was suffering through the swells of high and low sugars?

The rise in blood glucose is only from the liver, the glycogen in muscles cannot get out again is i remember from my biochem lessons in my uni days.

 

[Ermintrude775]

Can't remember where I saw it but they recommended drinking some lucozade or full sugar drink to counteract this effect. Personally I've not seen much help when trying this.

 

[MikeyU]

The rise in blood glucose is only from the liver, the glycogen in muscles cannot get out again is i remember from my biochem lessons in my uni days.

That is correct. In general, the more strenuous/vigorous exercise, the more sugar will be dumped by the liver (it can increase output tenfold and more but the muscles can only take up to let's say 4 times more glycogen then normal, hence the disparity and extra glucose in the blood, especially diabetics with low(er) insulin sensitivity. This does however subside after couple of hours. It seems that best time to do intense exercises is early in the morning, fasting, before breakfast. It'll bump up the metabolic rate and set the trend for the whole day which in the end will result in lower average daily BG levels. It works for me. I had 5.7 this morning when I woke up at 6:00, did a 5km run at quite a fast pace and my BG 30 mins after the run but before breakfast was still 5.7. 2 hours postprandial (I had 2 slices of whole grain rye bread with 1/4 avocado and a couple of slices of cold pork roast,, approx. 25 grams of carbs) my BG went down to 5.2. On days that I do not run in the morning postprandial would be somewhere around mid 6's. If I run in the afternoon/evening, I will always get approx. 0.5-1.0 mmol/l higher readings than before the run.

 

[MikeyU]

Can't remember where I saw it but they recommended drinking some lucozade or full sugar drink to counteract this effect. Personally I've not seen much help when trying this.

In my experience this does not stop liver from dumping... or rather may dump slightly less but net effect will be circa the same,

 

[MikeyU]

Checked sugar when I got home, really pleased 6.6, took when I got home after a walk 7.5 ! Anyone know why the increase ?

I just read your post again and realised that you get higher reading after walking. By all means this is not a strenuous exercise. The phenomenon I described usually happens when we exercise at or above 85% of HR max when our bodies switch to anaerobic metabolism. That's when we start burning glucose rather than fat and that;s when our livers start dumping massive amounts of glucose.

It may be that you are in relatively poor physical shape and even light exercise causes effect like this. Just keep on exercising, slowly increase intensity and eventually, when your fitness levels increase in few weeks or so, your BG levels shall improve as well.

 

[kitedoc]

The rise in blood glucose is only from the liver, the glycogen in muscles cannot get out again is i remember from my biochem lessons in my uni days.

Thank you @ Millennium. you are correct. I shall post an edit.

 

[millenium]

That is correct. In general, the more strenuous/vigorous exercise, the more sugar will be dumped by the liver (it can increase output tenfold and more but the muscles can only take up to let's say 4 times more glycogen then normal, hence the disparity and extra glucose in the blood, especially diabetics with low(er) insulin sensitivity. This does however subside after couple of hours. It seems that best time to do intense exercises is early in the morning, fasting, before breakfast. It'll bump up the metabolic rate and set the trend for the whole day which in the end will result in lower average daily BG levels. It works for me. I had 5.7 this morning when I woke up at 6:00, did a 5km run at quite a fast pace and my BG 30 mins after the run but before breakfast was still 5.7. 2 hours postprandial (I had 2 slices of whole grain rye bread with 1/4 avocado and a couple of slices of cold pork roast,, approx. 25 grams of carbs) my BG went down to 5.2. On days that I do not run in the morning postprandial would be somewhere around mid 6's. If I run in the afternoon/evening, I will always get approx. 0.5-1.0 mmol/l higher readings than before the run.

I also read that if bg is below 5.6, it is too low to exercise. So is it good for a person to exercise first thing after awakening? I probably do it one hour after a breakfast that increase my bg to 7-8.

 

[Alison Campbell]

I also read that if bg is below 5.6, it is too low to exercise

5.6 is a perfectly normal level. I am sure that information would only apply to people on medication that could cause hypos.

 

[millenium]

5.6 is a perfectly normal level. I am sure that information would only apply to people on medication that could cause hypos.

Ok. I will test that out.

 

[kitedoc]

just another cautionary tale.
If my BSL is at 14 mmol/l or more, then exercising is a no-no. @millenium might be able to help me here with the biochemistry.
At this sort of BSL apparently the liver starts sending glucose into the blood stream, like it recognises that at this and higher BSLS my body is starving. If I exercise at this level I end up with higher BSLs and feel mighty sick.
I give myself a correction bolus, check that my insulin pump and needle site are OK, that I am not coming down with an infection. I might an intramuscular injection of Novorapid in my case to get quicker absorption and thus action from the insulin.
Once down to 10 mmol/l or so I feel much better and then might do a little exercise to improve my insulin sensitivity.

 

[millenium]

just another cautionary tale.
If my BSL is at 14 mmol/l or more, then exercising is a no-no. @millenium might be able to help me here with the biochemistry.
At this sort of BSL apparently the liver starts sending glucose into the blood stream, like it recognises that at this and higher BSLS my body is starving. If I exercise at this level I end up with higher BSLs and feel mighty sick.
I give myself a correction bolus, check that my insulin pump and needle site are OK, that I am not coming down with an infection. I might an intramuscular injection of Novorapid in my case to get quicker absorption and thus action from the insulin.
Once down to 10 mmol/l or so I feel much better and then might do a little exercise to improve my insulin sensitivity.

I only did very basic textbook biochem in uni. My major is in human nutrition. So i have learned a lot from the people here with regards to practical knowledge on good diabetic control. The site i read recommends 5.6-13.9 for exercising is ok to go.

 

[kitedoc]

I only did very basic textbook biochem in uni. My major is in human nutrition. So i have learned a lot from the people here with regards to practical knowledge on good diabetic control. The site i read recommends 5.6-13.9 for exercising is ok to go.

Thank you @millenium !

 

[Juicyj]

I agree with higher glucose levels, I find if I am over 12 mmol/l when running that my muscles ache and my breathing is more shallow, I find it alot harder to run when high, it's the process of getting glucose into the muscles which I lack, I always try and stay below 10 if possible and monitor every 20 mins.