The Impact of Training Start Time on Dancer Recovery: A Quantitative Prospective Cohort Study Over a Season / Steffen Fuchs (2025)

Professional ballet dancers face continuous physical, technical, and mental demands across long performance seasons. This thesis examined two related aims: first, the validity of a widely used, affordable 2D motion analysis tool (Kinovea) for ballet-specific jumps involving external leg rotation (turnout); second, the influence of a single rest day following public performances on dancers’ subjective and objective recovery. A prospective longitudinal study with eighteen professional ballet dancers from Theater Koblenz assessed objective performance measures (jump height, joint kinematics via 2D video analysis using Kinovea) and subjective recovery (TRQ-10, CR-10) across 31 performances. To evaluate the accuracy of this measurement method, a separate validation study was conducted, analysing 820 ballet-specific countermovement jumps recorded independently and compared to 3D reference data. The validation results revealed systematic measurement errors in hip, knee, and ankle joint angles during turnout positions (all p < .001), while sagittal trunk angles were recorded with acceptable accuracy. In the recovery analysis, subjective recovery scores were significantly better after rest days (β = +1.27; p < .001), though objective performance outcomes showed no consistent changes. Higher perceived exertion correlated with reduced subjective recovery but not with the objective metrics. Together, these findings underscore the importance of reliable, context-sensitive motion assessment tools in professional ballet and highlight how even a single planned rest day can improve dancers’ perceived recovery without necessarily affecting their short-term physical performance. Key Points • Rest days improve professional ballet dancers’ subjective recovery after performances. • 2D motion analysis shows systematic errors for ballet-specific turnout poses in the sagittal plane. • Recovery planning and reliable motion assessment are crucial for dancer health and performance. Keywords: ballet, recovery, rest day, 2D video analysis, Kinovea, biomechanics