While there's a whole host of reasons for why it's good (both mentally and physically) to be an early bird, one great benefit is the ability to easily wake up early -- and get that exercise in first thing in the morning.
And there's tons of perks to a.m. fitness, whether it's being witness to the beautiful sunrise, or the feeling that you started your day off on a productive note. One study even suggests it could help you better manage cravings.
While some research suggests that the late afternoon is an optimal time to exercise, we'd like to posit that morning workouts have their advantages. And even if you're not a natural to the whole "exertion in the morning" thing, take heart: you can train your body to reach its personal best simply by sticking to exercise at the same time each day, according to research from the University of Texas, Denton (researchers there found that people reported less fatigue and better performance if they worked out at the same time each day)
In other words: force yourself up and eventually it'll be second nature.