Anthropometric variables and muscle properties of Japanese female ballet dancers.

Physiological characteristics of japanese female classical ballet dancers were investigated in comparison with sedentary women of similar age (non-dancers). Subjects were 20 professional female ballet dancers with a mean age of 26.5 +/- 4.4 years (mean +/- SD) and 66 sedentary women with a mean age of 23.7 +/- 3.6 years. Dancers had been trained in ballet classes for 20.4 +/- 2.4 years and had no experience of regular exercises except dance training. Body mass and % body fat measured by under-water weighing method were significantly smaller in the dancers than in the non-dancers. For all extremities, percentage of the muscle in total cross-sectional area calculated by ultra sound apparatus was significantly larger and percentage of the adipose tissue in total cross-sectional area was significantly smaller in the dancers. The maximal isometric and isokinetic force of knee flexors and the maximal isometric force of dorsi flexors (MVC force) were significantly larger in the dancers when the values were divided by body mass of each subject. During 50 repetitions of maximal plantar flexion, the isometric force of the dancers was significantly larger in all repetitions except first and second reps, though no significant difference was observed in MVC force during plantar flexion. It was suggested that the significant differences between the dancers and the non-dancers in some physiological variables might be attributed to the characteristics of dance movements/training.