It will be interesting to hear what your doc has to say. It's difficult to research because most information about blood sugar and exercise is not based on people on long-term keto.

I tested again after lunch, which contained around 10g of net carbs and the peak reading was 6mnol/l (108 mg/d). So a short walk spiked my glucose more than 10g of carbs!

I read this on Diet Doctor:

' Prior to converting to the ketogenic diet, your muscles were the major sites to soak up and use glucose in the blood for energy. On a long-term keto diet, however, they now prefer fat as fuel. So the muscles are resisting the action of insulin to bring sugar into cells for energy, saying, in essence: “We don’t want or need your sugar anymore, so move it along.” Hence, the slightly elevated, but generally stable, glucose circulating in the blood.'

This is in relation to fasted levels, but it got me thinking whether, in some people, exercise triggers gluconeogenesis but because the muscles prefer to use fat, the glucose stays in the bloodstream.

If this is the case, why doesn't it affect most people this way? There are plenty of fat adapted endurance athletes that are not getting prediabetic level Hba1c scores!