I do my workout rides in the morning, since it's a lot cooler than trying to ride in the heat of the day during the summer. But I don't do anything for energy. I get up at 5 AM and just go out and ride 10 miles, then go back home, do my morning get-ready-for-work routine which includes breakfast. I always seem to have enough energy to ride 10 miles in under 45 minutes.
Now I will admit that sometimes at 5 AM I'm too tired to drag myself out of bed and ride, on those mornings I sleep in until 6 and skip the ride. Sometimes I just need sleep.