Physiological Characteristics of Young (9-12 Years) and Adolescent (≥13 Years) Rhythmic, Acrobatic, and Artistic Female Gymnasts

Background: Elite gymnasts are exposed to high levels of physical stress, during both childhood and adolescence, with significantly late maturation and high injury prevalence. Here, we compare the physiological characteristics of female gymnasts in 2 age groups: young (9-12 years) and adolescent (>= 13 years) in 3 disciplines of competitive gymnastics. Hypothesis: Participants' physiological characteristics will differ by age group and by gymnastic discipline. Study Design: Cohort study. Level of Evidence: Level 2. Methods: The study included 274 gymnasts, aged 11.8 +/- 1.9 years. Data collection included anthropometric measures, Tanner stage, and menarche age; ultrasound assessments were used to assess bone properties, including bone strength, skeletal age, and final-height prediction. Results: Univariate analysis of variance showed age x discipline interactions for body mass index (BMI) percentiles (F-(2,F- 266) = 4.379; P = 0.01), skeletal age (F-(2,F- 241) = 3.808; P = 0.02), and final-height prediction (F-(2,F- 240) = 3.377, P = 0.04). Moreover, in both age groups, artistic gymnasts exhibited significantly higher BMI percentiles than rhythmic gymnasts (P < 0.05). In the adolescent group, final-height prediction for rhythmic gymnasts was significantly greater than that of artistic gymnasts (P < 0.05). Finally, in adolescent gymnasts, regression lines showed that skeletal age was lower than chronological age (P < 0.05). Conclusion: Artistic gymnasts were shorter than rhythmic and acrobatic gymnasts. Despite similar BMI and body fat, maturity patterns, and training-volume history, artistic gymnasts had lower bone-strength than rhythmic and acrobatic gymnasts. Combined with their high-impact and intensive training, this could increase their risk of musculoskeletal injuries. Clinical Relevance: The current study may help athletic trainers and medical teams define "norms" for different age groups and gymnastic disciplines, based on what may be expected during the athletes' early and late maturation. This knowledge can be used to modify, individualize, and optimize training programs.