I only make it to the gym 3-4 days a week and when I do, I don't even get to the gym until 11:30-12midnight, after I am done working. I can never head to the gym knowing I have so much to do that day, and I'm too tired in the morning usually.. I dont feel fully awake until 2-3 hours after I've woken up!
So I go to the gym from about 12-1:30 then go home and go to bed around 2 and usually fall right asleep. The next morning when I wake up I am usually feeling the burn in my muscles!