funny story, I was just thinking about this the other day. I always used to sleep like a rock even before I started training Jiu Jitsu. I have done 2 tours in Iraq and upon completion of my second tour, which was physically very demanding. I returned home and could not sleep, everyone I talked to said it could be PTSD. I now know what it was, but first let's flash forward. I have just moved about 5 states away and am now getting started in a new city, one of the things to suffer from the move is that I am not currently training anywhere, and I haven't started working yet. Last night I was up until 4 a.m. and wide awake. I now know what has been keeping me up late into the night. My body has been used to large amounts of physical activity with 5 years in the army and then 1 year of training jiu jitsu, that when I am not expending energy my body will stay up for up to 20 hours a day. needless to say I used to sleep well and I have to get back into the gym.