I think it is because of the weight lifting! In short time after starting a nautilus program you feel stronger and your muscles "wake up". I look lumpy as I like to call it! I got amaaazing sleep last night as well and lastly, I've decided to schedule in a day off/week (as oppossed to missing a scheduled day at gym). This will allow me to rest, less pressure of trying to go daily, and its a treat to wake up at 4 and know I've got more sleep comin'!