Exercising in ketosis - BG goes up! Freestyle Libre.

[LittleGreyCat]

Starting a separate post because this is exercise related.

Since I got my first Freestyle Libre I have seen various puzzling things.

One was that when I went for a long cycle ride after only coffee+cream+butter my BG went up during the ride.
It dipped a bit during the coffee stop (I had black coffee) but then went up again during the second part of the ride.

I blamed the coffee but today I rode with just a drink ow water and one small slice of cheese before the ride, and only water during the ride, but again my BG went up during the ride.
It is coming down quite rapidly now I am no longer riding.

Has anyone else had their BG go up when exercising in ketosis?

I have to assume that my body (liver?) is making glucose as I assume that it is also making ketones for my body to use as energy.

 

[LittleGreyCat]

Well, further data suggests strongly that exercise does send up/keep up my BG.

Coffee followed by no exercise shows a short ramp up (really following the trend line of a steady gradual rise from midnight) followed by a reasonably steep drop in BG.

Coffee followed by exercise sees my BG stay at the top of the upslope throughout the exercise period and only start to come down after the end of the exercise.

Exercise on ham and eggs instead of coffee (ham and eggs later in the day does not raise BG at all) shows the same ramp up and plateau effect, then the drop after the end of exercise.

I can even see a slight dip during the mid ride coffee break (water only for me on the "no coffee" ride) then a small rise again when the second half of the ride starts.

All in all a bit of a puzzle.

 

[bulkbiker]

Quite a few people report elevated blood glucose when doing strenuous exercise..
I guess you need to try it with a gentle walk to see if that has the same effect?

 

[LittleGreyCat]

I really do not understand what is going on.
Yesterday I went for a long ride (just over 30 miles) as opposed to the usual group ride of (10 miles + coffee break +10 miles).
The ride did have a break about 20 miles in (browsing bike shop) but no sitting down and resting.

My BG behaved as originally expected; ramp up of what I am now thinking of as "extended dawn phenomenon" plus what seems to be an additional ramp up from (coffee + butter + cream) but after peaking roughly 2 hours after the coffee, it then came down in the expected steep slope.

So what was different?

The only obvious thing was the lack of a rest stop at the 10 miles/1 hour point.
Why would that make such a difference?

I'm having a BR coffee day without the ride today and the peak of the usual ramp up isn't as high and after a brief spike (above the usual upwards ramp) at the 2 hour mark my BG now seems to be dropping. Which is very similar to the slope with the exercise yesterday.

A no coffee day tomorrow, I think.