How does exercise affect insulin response or glucose uptake?

[Vectian]

I found out early on that walking helps to bring down BS more quickly after eating, but I am trying to understand the mechanism. Is it that your muscles are directly using up the glucose in your blood and that is why it goes down quickly? 10 mins walking burns around 40 calories, so certainly won't be using up all that much of the energy taken in with a decent meal.

Or does it speed up/ increase the effect of insulin somehow so that the reduction in BS after exercise comes via insulin but more quickly? Or I read something about exercise allowing the glucose to enter your cells via a separate mechanism to insulin, in which case it must allow more energy into your cells than is actually used up by the exercise. If that is the case, could you theoretically have no insulin at all but maintain BS levels by the right amount of exercise?

 

[Martin.A]

A post-meal walk always gives me a lower post-prandial reading at the 2-hour mark compared to what my food diary tells me is my average for whatever meal I've had, ie gentle exercise uses the glucose that's already in your bloodstream.

As to your question about an alternative mechanism for getting glucose into cells, if you have no insulin at all I suspect you might be heading for A&E under blue lights.

 

[harbottle]

Muscles take in glucose during exercise via a different transport mechanism (GLUT4?) They also become more insulin sensitive. The liver also releases more glucose to act as fuel.

 

[Vectian]

A post-meal walk always gives me a lower post-prandial reading at the 2-hour mark compared to what my food diary tells me is my average for whatever meal I've had, ie gentle exercise uses the glucose that's already in your bloodstream.

As to your question about an alternative mechanism for getting glucose into cells, if you have no insulin at all I suspect you might be heading for A&E under blue lights.

I don't think it's as simple as just using up the glucose in your blood, as even 10 mins walk (for me) lowers BS quickly and by a fair amount, and the amount of energy being used in 10 mins walking is not a lot. It was a theoretical question of course, but if the exercise allows glucose to enter your cells regardless of insulin (if that is true) then it should be theoretically possibly, although obviously not a very practical way of living!

 

[grovesy]

I don't think it's as simple as just using up the glucose in your blood, as even 10 mins walk (for me) lowers BS quickly and by a fair amount, and the amount of energy being used in 10 mins walking is not a lot. It was a theoretical question of course, but if the exercise allows glucose to enter your cells regardless of insulin (if that is true) then it should be theoretically possibly, although obviously not a very practical way of livi

Personally 10 nins walk for me does nothing, I need at least 20 mins.

 

[everydayupsanddowns]

As I understand it some levels of exercise allow direct uptake of glucose from the blood without insulin.

Muscles are used to store glucose, and this can be released during exercise to fuel the body. Most dramatically this can happen during anaerobic exercise which can result in a surge of glucose in the bloodstream. But i think it also happens more gently during cardio-type exercise.

The muscles then restock directly from the bloodstream I think.

But yes, I notice that exercise, even a fairly gentle stroll has the capacity to ‘supercharge’ and insulin-on-board with increased insulin sensitivity too.