It is really a matter of preference, and weather or not it is a viable option for you. Most people including myself, can't work out in the morning because of other conflicts (work, school, etc). I used to work out in the morning before I started working and it was great. Your energy levels are at their highest coming off of a good nights rest, giving you the ability to train really hard. But I had to adjust my training around my other reponsibilites. Eventually your body adjusts. I come home from work, take a nap and hit the gym, without the nap I'd have a shitty workout becaues I'm tired from working all day. On weekends though since I have the time, I train early. That way I have the rest of the day free, and don't have to worry that I have to hit the gym later. But ultimatley it is a matter of preference. When you feel you have the maximum energy, and are able to get the best workout. If it were a perfect world I'd be there in the morning.