I used to be an early riser. I would get up at 5 am by waking up to the gruelling sound of an alarm. I would then get up and start my day.
I was up before others, and I was productive. However, there was a downside to this...
When the afternoon would hit, I was feeling like a zombie; I could barely keep my eyes open, and doing my work (I was a web developer at that time) was almost impossible.
Eventually, I got fed up with this lifestyle, being chronically sleep-deprived, unable to focus on the tasks at hand, and just generally feeling bad.