Relationship between nutrient intake, body mass index, menstrual function, and ballet injury.

The effects of inadequate nutrition, menstrual dysfunction, and low body weight on the injury rate of ballerinas were studied. Forty-nine female ballet dancers, mean age 18.7 years, completed food frequency and injury questionnaires. Subjects were placed in one of two groups: those with an intake less than 70% of the Recommended Dietary Allowances (RDA) for key nutrients and those with an intake greater than 70% of the RDA for key nutrients. Sixty-nine percent of the dancers had intakes less than 70% of the RDA and were randomly assigned to either a vitamin/mineral supplement or to placebo for 6 months. The remaining dancers with diets adequate (greater than 70% RDA) in key nutrients received no treatment. All groups were questioned monthly about the incidence, severity, and nature of ballet injuries. Information regarding menses and height and weight was obtained. There were no significant differences in the severity or type of injuries among the dancers in the supplement, placebo, or no treatment groups. Dancers with abnormal menses had more bone injuries (mean = 15.00) than normally menstruating dancers (mean = 4.97) (p less than .05). Dancers with a Body Mass Index less than 19.0 spent more days with a low-grade injury (mean = 24.05) than dancers with a greater BMI (mean = 11.63) (p less than .05). There appears to be a relationship between dance injuries and both BMI and menstrual function.