Take a ballet class, the more the better. These classes will allow you to build the proper muscles and learn the techniques that will allow your body to strengthen itself. Try to take ballet classes for at least four hours per week.
Eat healthy and sensible meals in order to maintain a certain weight and be able to build the correct muscles. Excessive fat will create unusual fat deposits and will mask the muscular curves of a ballet body.
Take Pilates classes. Pilates is perfect for building the interior muscles that allow ballerinas to have their long, lean appearance. While ballet helps build some exterior muscles, Pilates strengthens the core and hamstrings, allowing you to become a better dancer. Yoga is also advised to increase flexibility.
Perform a varied cardiovascular workout. This will help you build endurance and stamina. Variation is necessary to avoid building one muscle group too much. Alternate between activities such a jogging, swimming, and kickboxing.
Build your ankle strength. This is of utmost importance for ballerinas. Use resistance bands and other aids to work out your ankles.