Although classical ballet is an artistic expression through the use of the body, there is a real opportunity to improve and extend the dancer's career by simply applying sports science principles to dance training and performance. Dance training is a long process of physical, intellectual, and psychological preparation, through physical exercise, often beginning in childhood and continuing until retirement. Fitness programs, supplementary to traditional dance classes, have only recently been considered as a part of this process; it may be suggested that this cross-training has generally been avoided thus far because of tradition and a reluctance to follow principles associated with sport. Classical ballet training, rehearsal, and performance do not elicit significant stimulus to result in increased aerobic fitness levels. Therefore, dancers often demonstrate low levels of aerobic fitness even though a strong aerobic foundation is necessary to meet the required workload. Dancers have greater than average range of motion and strength at the hip joint but weaknesses in the upper body, torso, hamstrings, and quadriceps. In the past, dancers have been wary of strength training because they perceive this leads to aesthetically undesirable hypertrophy. Dancers also have low body weights and low percentage body fat. Given that training does not provide the opportunity to expend enough energy to maintain these aesthetic demands, this aesthetic demand may be met by caloric restriction, which may lead to subsequent increased injury risk. It has been hypothesized that a "fit for purpose" body can help improve performance, reduce the risk of injury, and ensure prolonged dance careers. This review aims to explore the extent to which physical fitness components relate to dance performance, in particular classical ballet.