I have a couple of questions for the exercise/diet/low-carb physiology experts out there …
After three months away from home (bad sleeping —> worse than usual BGs + excessive hunger —> Hba1c up to 6.9 from 6.3 + about 10 extra pounds of weight), I’m attempting a more serious low-carb trial, with the goals of getting back to my usual weight and investigating the impact of a lower carb diet on my A1c.
My first question is more a general request for advice on the weight-loss front (re. frequency and content of meals + anything else that seems relevant). I work out at quite a high intensity most days (cardio + strength, masters rowing) and continued to do so during my weight gain phase, so adding in more exercise isn’t something I’m inclined to do.
The second question is a bit more specific. I know that on a relatively high-carb diet, the body uses glucose as its primary fuel and that very low-carb (ketogenic) diets will result in fatty acids / ketone bodies being used instead. What I’m wondering is if the fuel “choice” is an either/or thing — particularly with regard to intensive exercise — or if we can go back and forth between the two. If an athlete has been on a ketogenic diet for several weeks, will his/her body continue to favour fat as its fuel source, or, in the sudden presence of higher-than-usual glucose, will it revert back to glycolysis? I’ve read that glycolysis is preferable, performance-wise, for sprints and other anaerobic activities — not that I do any serious racing, but I’m curious.