Data extraction and analysis methods

Data extraction will follow a structured template developed in accordance with the Joanna Briggs Institute (JBI) methodology for scoping reviews. Extracted variables will include study characteristics, participant demographics, supplement type and dosage, sleep-related outcomes, recovery markers, and endurance-performance measures. Title and abstract screening will be completed in Rayyan, which will also be used for duplicate removal. Full-text screening and reference management will be performed in Zotero.

Extracted data will be summarised descriptively, with results mapped according to key themes such as supplement type, sleep outcomes, recovery outcomes, and endurance-performance effects. The review will not include risk-of-bias assessment, consistent with JBI scoping review guidance. Reporting will adhere to PRISMA-ScR standards, and all search strategies, screening outputs, and extraction files will be stored in OSF to ensure transparency and reproducibility.