Depends on the person, the goals....I go @ 5am when they open, I never know what time I'm leaving my office @ night..plus when I do leave I am mentally shot as opposed to being fresh 1st thing in the AM...
Also I hate walking into an episode of Jersey Shore @ night...
If you're bulking it's better to go after getting some good quantities of protein & carbs, maybe 2-3 meals worth @ least...
Observation on training @ 5am; I have 2 memberships, at one gym I'm the youngest person there in the morning, at the other gym I'm the oldest...
But @ either one I'm the best (but only cuz Arabian isn't there)
~EZ