Good line is partly a matter of the physique a dancer is born with, but it can also be developed and enhanced by training. In ballet, certain relationships of the arms, legs, head, and torso are considered particularly harmonious, while others are not, although they may be perfectly acceptable in different forms of dance. Large movements of the whole limb are preferred to small, isolated movements of individual body parts. These systems, however, differ more in style and emphasis than in the actual movements taught. Younger children may be harmed by the strenuous physical demands of a ballet class, and older children gradually lose the flexibility required to attain good turnout.
Girls usually begin pointe work after three years of training.
If training is begun after the late teens, it is probably unrealistic to hope for a professional career. All dancers, no matter how experienced or proficient, take daily class to keep their bodies supple and strong. Most ballet classes begin with exercises at the barre, a round horizontal bar that the dancer holds onto for support. These exercises warm up and stretch the muscles, work the tendons to make them supple, and loosen the joints. The second part of the class is done without the support of the barre and is called center practice.