I didn't eat before exercise but it rises after, is it normal?

[jf1223]

Hi everyone,

I am new to here and I am a newly diagnosed type 2 diabetes on Nov 2020. Since then I have lost 15 KG already which I currently weight 93 KG and I am 28 years old.

I exercise 3 times a week (Weights and cardio) and my everyday fasting blood sugar stays around 4.6. So today I went and did cardio (without food) after an hour I tested my blood sugar it went up to 5.7, I just wanted to ask if this is normal and should I be worrry?

Thank you so much everyone!

 

[Goonergal]

Hi there and welcome to the forum.

Exercise can push blood glucose up temporarily. You’ll likely find that different forms of exercise will do different things - in my case a gentle walk will always bring it down, as will swimming. Weights or something more energetic like football will push them up for a short period.

As I got fitter (was very overweight and sedentary when diagnosed), the rises got less, and also the time of day makes a difference. For me, the rise, if there is one, is always more in the morning.

No need to worry, it’s normal and the health benefits of exercise are very strong.

I also exercise fasted, even for fairly challenging walks and activities. I find it helps with performance, as well as insulin resistance, so there’s no problem with you doing that either.

 

[woollygal]

Yes.
When you exercise the body needs energy so the liver dumps glucose in your boood stream. The rise should be short lived then drop lower.
In the short term it’s a rise but long term exercise helps to reduce sugars.
Even if I go for a long walk my sugars rise, anything, even putting the bins out. I don’t eat before working out as I get reflux etc.
It’s actually quite handy because when I was younger I always used to run out of energy in working out and feel lousy (assuming sugars dropped) I wasn’t diabetic then

 

[jf1223]

Hi there and welcome to the forum.

Exercise can push blood glucose up temporarily. You’ll likely find that different forms of exercise will do different things - in my case a gentle walk will always bring it down, as will swimming. Weights or something more energetic like football will push them up for a short period.

As I got fitter (was very overweight and sedentary when diagnosed), the rises got less, and also the time of day makes a difference. For me, the rise, if there is one, is always more in the morning.

No need to worry, it’s normal and the health benefits of exercise are very strong.

I also exercise fasted, even for fairly challenging walks and activities. I find it helps with performance, as well as insulin resistance, so there’s no problem with you doing that either.

Thank you so much for your quick reply. Because I get very anxious since I thought I am fasting and I wonder why my blood sugar went up when I didn't eat and I keep pricking my finger thought the blood sugar will go lower And is my blood sugar 5.7 too high after exercise considering I didn't eat ?

 

[jf1223]

Yes.
When you exercise the body needs energy so the liver dumps glucose in your boood stream. The rise should be short lived then drop lower.
In the short term it’s a rise but long term exercise helps to reduce sugars.
Even if I go for a long walk my sugars rise, anything, even putting the bins out. I don’t eat before working out as I get reflux etc.
It’s actually quite handy because when I was younger I always used to run out of energy in working out and feel lousy (assuming sugars dropped) I wasn’t diabetic then

Hi thank you so much for your reply. I am just wondering what is a desire blood sugar level be after exercising? Is mine too high 5.7 considering I didn't eat at all

 

[Goonergal]

Thank you so much for your quick reply. Because I get very anxious since I thought I am fasting and I wonder why my blood sugar went up when I didn't eat and I keep pricking my finger thought the blood sugar will go lower And is my blood sugar 5.7 too high after exercise considering I didn't eat ?

What constitutes ‘too high’ is quite a personal thing based on your usual numbers/control, but 5.7 is not a high number, especially as you’re recently diagnosed and if you were at 4.6 before, it’s only a small rise. Blood glucose doesn’t stay continuous all day. There will always be fluctuations even when at rest or fasting.

Sounds to me like you’re making great progress.

 

[sno0opy]

I personally don't think there is such a thing as too high after exercise - if its natural and not food related

If you are excersiseing your body needs and uses the glucose so it releases it which is healthy and helps reduce your body's insulin resistance as you do it more.

I made a very similar post when I first started 18 months ago. At the time i was 105kg, and my bloods went to 8's or even 9's when i did hard cardio. They never stayed up there for long and my HBA1C during this time dropped significantly.

3 months on, having carried on doing it 4 times a week doing the same (actually much more intense set), but bloods barely rise. My body is still using the same if not more glucose to power the exercise, but my muscles have remembers how to use it properly so it just gets converted into energy rather then floating around in my blood.

Now im 75kg and i run a half marathon, with a 100g carb snacks half way and still don't see a rise

 

[Maco]

Agree with snoopy about not being a case of too high after exercise. At the minute I’m following a bodybuilders lifestyle plan as if they where stripping for a show or something along them lines. I’m eating 1400-1500 calories a day & around 120-150g of carbs, when I train its around 1-2hrs of intense weightlifting. Each set the weights increase until finally your last set you can literally only do 4/5 reps until failure. I quite regularly see an increase from 6/7mmol to 15/16mmol because of how intense I am training. I’m using the new Medtronic 780G so I’ve spoke to both Medtronic & my DSN and they both said the same. Do what your doing let your readings raise aslong as the pump is correcting them within 2hrs. Normally I drop like a rock around an hour after I stop training so like snoopy said it’s just a natural thing. I actually have to turn my pumps temp target of 8.3 on because if I don’t I’ll regularly go hypo later on

 

[EllieM]

I actually have to turn my pumps temp target of 8.3 on because if I don’t I’ll regularly go hypo later on

Like you I'm T1 and gym exercise usually sends me up (unless I've got recent bolus in my system in which case reduced insulin resistance can send me down, thank goodness for my dexcom). But I have T2 tendencies (aka insulin resistance, thanks T2 dad) and I find that the more exercise I take the better my insulin works - and after my gym session yesterday I was hypo by evening (sigh).

 

[jf1223]

What constitutes ‘too high’ is quite a personal thing based on your usual numbers/control, but 5.7 is not a high number, especially as you’re recently diagnosed and if you were at 4.6 before, it’s only a small rise. Blood glucose doesn’t stay continuous all day. There will always be fluctuations even when at rest or fasting.

Sounds to me like you’re making great progress.

Hi, thank you so much for your reply. Now I understand this is a natural process and I do not need to be worry about it! Is it okay if I can ask you another question?

I have noticed that sometimes my blood sugar will rises 3 hours after meal (lets say my 2 hours after meal blood sugar was 7.3 and then it will goes up to 7.8) I wonder if that is normal too? But eventually around 5 hours after meal my blood sugar will be 5-5.3 again.

Thank you

 

[jf1223]

I personally don't think there is such a thing as too high after exercise - if its natural and not food related

If you are excersiseing your body needs and uses the glucose so it releases it which is healthy and helps reduce your body's insulin resistance as you do it more.

I made a very similar post when I first started 18 months ago. At the time i was 105kg, and my bloods went to 8's or even 9's when i did hard cardio. They never stayed up there for long and my HBA1C during this time dropped significantly.

3 months on, having carried on doing it 4 times a week doing the same (actually much more intense set), but bloods barely rise. My body is still using the same if not more glucose to power the exercise, but my muscles have remembers how to use it properly so it just gets converted into energy rather then floating around in my blood.

Now im 75kg and i run a half marathon, with a 100g carb snacks half way and still don't see a rise

Thank you so much for your reply, as you said do you mean it is natural for people to have their blood sugar rises after exercise? Also do you mean by time if I exercise more my blood sugar won't rises that much? Thanks you so much

 

[jf1223]

Agree with snoopy about not being a case of too high after exercise. At the minute I’m following a bodybuilders lifestyle plan as if they where stripping for a show or something along them lines. I’m eating 1400-1500 calories a day & around 120-150g of carbs, when I train its around 1-2hrs of intense weightlifting. Each set the weights increase until finally your last set you can literally only do 4/5 reps until failure. I quite regularly see an increase from 6/7mmol to 15/16mmol because of how intense I am training. I’m using the new Medtronic 780G so I’ve spoke to both Medtronic & my DSN and they both said the same. Do what your doing let your readings raise aslong as the pump is correcting them within 2hrs. Normally I drop like a rock around an hour after I stop training so like snoopy said it’s just a natural thing. I actually have to turn my pumps temp target of 8.3 on because if I don’t I’ll regularly go hypo later on

Thank you so much for your reply! I wonder if this applies to Type 2 too because I am only on Metformin.

 

[EllieM]

Thank you so much for your reply! I wonder if this applies to Type 2 too because I am only on Metformin.

Basically, yes. Intense exercise makes your level go up (stress hormones plus sugar from liver) in the short term but in the long term pushes them down (less sugar in liver plus, more important, less insulin resistance). Don't hesitate to exercise because of short term rises (particularly when, in your case, those rises are still within non diabetic levels. Exercise is good for everyone, diabetics and non diabetics.

But honestly your blood sugar readings are excellent, it sounds like you're pretty well always in normal range, it's just that you failed the glucose tolerance test. (I read your other posts). Most doctors in the UK would diagnose you as prediabetic rather than diabetic so I'd try not to stress too much.

Can I ask which country you live in? Not sure a UK GP would give you a diabetic diagnosis on your readings (or even a prediabetes one). But am guessing that you were previously overweight which may have influenced the diagnosis?

 

[sno0opy]

This is from a study on different exercise on none diabetic athletes. basically, if you do high intensity exercise (for your body) your bloods go up.

Now clearly, if your diabetic they may go up a bit higher but its still natural, the long term benefit of reducing insulin resistance far out weighs the short term high.

So a non diabetic athlete at the peak of fitness with a resting blood glucose reading of 5, running at 70 - 85% max effort could expect to see blood glucose readings of 7.5 and that is perfectly normal and acceptable.

 

[jf1223]

Basically, yes. Intense exercise makes your level go up (stress hormones plus sugar from liver) in the short term but in the long term pushes them down (less sugar in liver plus, more important, less insulin resistance). Don't hesitate to exercise because of short term rises (particularly when, in your case, those rises are still within non diabetic levels. Exercise is good for everyone, diabetics and non diabetics.

But honestly your blood sugar readings are excellent, it sounds like you're pretty well always in normal range, it's just that you failed the glucose tolerance test. (I read your other posts). Most doctors in the UK would diagnose you as prediabetic rather than diabetic so I'd try not to stress too much.

Can I ask which country you live in? Not sure a UK GP would give you a diabetic diagnosis on your readings (or even a prediabetes one). But am guessing that you were previously overweight which may have influenced the diagnosis?

Hi Ellie, thank you so much for your reply. I have been stressing out since Nov because I have no one to talk to it about and I haven't found this forum yet.

I am currently in Australia and I always wonder if I am really diabetic? Because originally my first GP only did the fasting blood sugar test and hba1c then the results came back as I am on the pre-diabetes range (5.8) and he didn't even prescribed me any medication (I asked him twice if I need it and he told me as long as you lose weight you will be fine and he said I don't have diabetes just pre) but then after a week my parents asked me to go check with another GP and she assigned me to do the OGTT test which the 2 hours result was 12.4 and the GP said it is a confirmed diabetes which it puts me in shock and sadness. Therefore, I always wonder in that case do I really have diabetes or it is just pre-diabetes. Do you have any idea? Thank you so much for your words again, I definitely feel better after reading what you said.

 

[jf1223]

View attachment 47269

This is from a study on different exercise on none diabetic athletes. basically, if you do high intensity exercise (for your body) your bloods go up.

Now clearly, if your diabetic they may go up a bit higher but its still natural, the long term benefit of reducing insulin resistance far out weighs the short term high.

So a non diabetic athlete at the peak of fitness with a resting blood glucose reading of 5, running at 70 - 85% max effort could expect to see blood glucose readings of 7.5 and that is perfectly normal and acceptable.

Hi, thank you so much for the graph and your clear explanation. I can't be more than thankful for your time to reply. It really calms me a lot.

 

[EllieM]

Therefore, I always wonder in that case do I really have diabetes or it is just pre-diabetes. Do you have any idea?

Well, I'm not a doctor and we're not allowed to diagnose on this forum, but the dividing lines between non-diabetic, prediabetic and diabetic are a bit blurry, and can vary from country to country. In the UK, I suspect you might get a prediabetic diagnosis. But weight gain is a symptom of T2 diabetes so all that suggests that maybe you did have some insulin resistance, at least before you lost the weight, so you are prone to T2 diabetes if you don't watch your diet and exercise. So, pile on the carbs, pile on the weight and insulin resistance. Remove the carbs, the weight and insulin resistance go down.

Is the weight loss due to exercise or did you also reduce the carbs in your diet? Whatever you did, your current levels are great, so keep doing it.