Juggling skill acquisition through air-toss and ground-bounce practice in college students: A study protocol for the TuJuggling cluster-randomised trial

Practice organization is vital for motor acquisition, yet pragmatic evidence on how instructional constraints shape learning in authentic settings remains scarce. The TuJuggling protocol establishes a standardised assessment and training framework for complex bimanual skills in novices using an ecological dynamics perspective.

In this cluster-randomised crossover trial, registered on ClinicalTrials.gov (Identifier: NCT07528924), 200 students will complete two 4-week juggling interventions: air-toss (A) and floor-rebound (B), separated by a 1-week washout. The primary outcome is a Global Composite Score (40 tasks) across stable (floor) and unstable (BOSU) surfaces. Secondary outcomes include cognitive functions (attentional/inhibitory control, visuospatial memory, and working memory), handgrip strength, and psychological factors (flow and affect). Assessments occur at baseline and after each intervention period.

Data will be analysed using linear mixed models (LMM) to evaluate the effects of method, period, and sequence while accounting for the cluster-based design. Missing data will be handled via Full Information Maximum Likelihood (FIML). Mediation models will further investigate whether psycho-cognitive shifts explain the observed motor training effects.

This protocol provides a rigorous framework to evaluate how physical constraints and exposure order shape coordination. Findings will offer evidence-based recommendations for sequencing motor skill progressions in higher education, bridging theoretical motor learning and applied pedagogy.