D - well, I know water is not the problem, I drink 128 oz of water daily (gallon and sometimes more). I got a full 8 hours of sleep last night and didn't go do my workout this morning, however I did it on my 2 hour lunch break and I feel absolutely wonderful today. I even increased my weights this time, and feel like I had the best workout ever. So I'm leaning toward the sleep being deprived as the reason for me being sluggish.
I think that is an excellent idea about your last meal being -0- carbs. I've been trying to do that myself. I'm very anxious to get to week 4 and I will take my measurements and see the progress.