I am going to start UD2 i think, but i do a lot of HIIT sprinting (30 minutes, alternate 1 min between wakling & running) that is fairly intense
I read somewhere this kind of cardio does something to your glycogen levels.. And am wondering if this will interfere with the glycogen depletion ideas behind UD2
It will deplete some glycogen stores. I would not recommend doing HIIT while on UD2 as you are already training legs a lot and are at such a severe caloric and carbohydrate deficit.
lyle believes it will lead to overtraining of the legs, if you are still insistent on doing it I would cut down on the depletion volume, I myself only really do a hiit session on sunday and short ones on wed,thurs about 5 minutes to target that stubborn fat.
somewhat what I eat...
There are several folks who have used HIIT (instead of weights) for Depletion successfully. It will take some trial and error before you know if you've depleted properly though.