A bit of a sticky wicket, that one. When I asked this same question a while back I was told to cut back to maintenance during SD. But you want to keep protein levels high so you don't lose muscle. And you don't want to cut calories so much that your body thinks you are dieting. So to keep protein high and calories lower, I have just been eating a bit less carbs. Carbs are an important energy source during workouts, so it makes some sense to cut them back when on an SD. Maybe start eating carbs again a couple days before the end of your SD...from what I hear the carbs used for energy during physical activity are not the ones you just ate, but the one ate in previous days.
Brak