Yeah, mostly from fat. I have been low carbing for so long that I think my body has adjusted to it . The only thing I use carbs for is refilling muscles and the insulin spike, thats it. I eat a little protein and olive oil prior to working out and I do fine. I tried eating carbs prior to working out and did not feel any difference so I cut them out. But, I am not a body builder, I train more like a power lifter, so as long as I keep my fat around 15 percent I am happy. At some point I will try to take it lower, but it is not my focus currently.