Spikes After Exercise

[HSSS]

I'm new to diabetes, monitoring and exercise. T2 no meds. I’ve been eating low carb/keto for about a month with initial weight loss of 4kg but nothing for the last week or so.

I’ve notice a walk or a swim will drop my BG. I just started using my bike and even though I’m really not riding hard or fast, but I can feel it in the muscles and am a little puffed whilst doing it, it has raised my BG. Usually only by less than a mmol but would have dropped by that amount over that time normally instead as I typically exercise 2hrs or so after a meal. Today I checked another hour later and it was down on the previous hour by nearly 2mmol

Now I know this isn’t unheard of but I really don’t understand it. Why does my body think it needs to dump glucose (from my liver I assume? But I thought being keto meant little glycogen stores) if I’m getting energy from fats. Is it ok because overall the exercise will do me more good than the spike will hurt? Can I do anything to prevent this spike and still get the exercise benefits? Should I fill up on fat or protein beforehand? Or even a little carbs?

 

[Deleted Account]

When we exercise, our body does two things whether we have diabetes or not
- it becomes more efficient at using insulin
- it thinks we will need extra glucose to provide the energy to maintain the exercise so dumps some from our liver

For those with healthy pancreas (without diabetes), their incredibly clever pancreas would adjust their insulin production to match these exercise effects and they would see little impact on their BG.

For those of us with diabetes the short term impact on BG would depend on the type of exercise, how long we do it and how fir we are (at that type of exercise).
Typically (but not always .. because we are all different), longer cardio exercise with little stress would see a drop in BG whereas resistance, stop-start cardio or cardio with some stress such as cycling uphill against a hot wind, may see a rise in BG in the short term.
However, due to the liver dump, the medium term impact (over the next 24 to 48 hours) is likely to be a reduced BG because we have less glucose in our liver to continuously drip and more of what we eat will go towards restocking these supplies.

 

[kitedoc]

Hi @Safin777,
If I do vigorous exercise my BSL rises. My doctor informed me that this is because of release of adrenaline. Adrenaline stimulates release of stored glucose in the liver - adrenaline is about preparing us for an emergency. Glucose release is part of the the mechanism to fuel our fight or flight.
Unfortunately there is not sufficient insulin automatically available in us diabetics to keep a lid on the BSL rise when this happens.
If the exercise was less vigorous or I was fitter then less adrenaline is released. And my BSLs does not rise too much and my bsls may lower a bit.
But later on those muscles I have been used and are aching a bit will make a call on the body to replenish the sugar stores in the muscles themselves. This comes out of the blood stream some 6 + hours later and may cause a low blood sugar at that time or later particularly if a diabetic is on insulin or other blood sugar lowering agent.
Being on insulin by pump I try to ensure that I either eat more carbs before that timing to prevent a hypo orI lower my insulin dosage to the same effect.
I hope that answers your query. My experience has been that life gets easier with graded exercise to gradually increase your fitness level but please check with your doctor about this.

 

[HSSS]

Ok I get what’s happening now and why. But what do I do about it?

I’m not on any meds so can’t use them to bring it down. Realistically I can’t cycle on much flatter roads (they really are only tiny slopes) or much slower. I’m can still talk when doing it so I’m not blasting it. I really want to get fitter, stronger and lose weight so giving up completely isn’t an option.

 

[kitedoc]

no need to give up !! All I can suggest is discussing it with your doctor. How high are the BSL rises? Are they significant? Would medication make a difference or only complicate things?

 

[HSSS]

No I won’t be giving up. Tbh trying to see a dr is a nightmare and it’s never the same one and my faith has been rocked by misdiagnosis in the past and a definite in and out attitude from most I have seen. When I tried to get strips after diagnosis even on a temporary basis to help identify triggers etc I was refused and put off because of my fingers and soreness! Would prefer the truth that it costs too much.
Medication is exactly what I’m hoping to avoid.
The rises are small so not a major worry but just seemed to be counterproductive and want to get the most out of any exercise I do achieve.

 

[kitedoc]

Sorry to hear that consulting a doctor is soo difficult to arrange.. If the BSL rises wth exercise are within what is suggested as desirable say 2 hours after a meal then I guess that may be OK. Perhaps a phone call to a dsn might help clarify things like that and also if you over that limit. I hope that you can keep exercising without worry !!