LeBron James, Maria Sharpova, Terrell Owens, Gabrielle Reece, Dwight Howard and Heather Mitts all have something in common beside being professional athletes... phenomenal bodies. And they didnt get that way just from playing their sports. They got that way from a lot of hard work in a lot of different styles of training as well as outstanding nutrition.
Let's say you run marathons or 10k's or something along those lines:
1) Are you eating properly for that sport? Are you taking in the correct amount of carbs at the right times?
2) Are you following your schedule and using your resistance training days? Are you training the muscles needed to not only help you run more efficiently but also the opposing muscles to help your body stay in proper alignment?
Whatever sport you play or whatever you do for your fitness, be sure your looking into all training methods and nutrition to get the benefits you need to be the best "you" you can be. Remember, to look like an athlete, to perform like an athlete, you have to eat and train like an athlete.