Supporting materials for "Reference-System Choice Alters Age- and Sex-Specific Fitness Classification in Colombian Schoolchildren: A Within-Participant Comparison of FUPRECOL and FitBack"

This repository contains the supporting materials for the article “Reference-System Choice Alters Age- and Sex-Specific Fitness Classification in Colombian Schoolchildren: A Within-Participant Comparison of FUPRECOL and FitBack”. The study examines whether Colombian FUPRECOL and European FitBack age- and sex-specific reference systems produce comparable classifications when applied to the same ALPHA-Fitness performances in 31 Colombian schoolchildren. The repository includes aggregated results, reproducible analysis code, reference-mapping documentation, a data dictionary, and a methodological change log. For cardiorespiratory fitness, the analysis maps the same recorded 20-m shuttle-run performance to the metric required by each reference system: completed stages for FitBack and cumulative shuttles for FUPRECOL. The materials also document the interpolation of published percentile points, quartile reclassification, bootstrap confidence intervals, and ordinal agreement analyses. Participant-level data are not included because the study involves minors from a small single-school sample, and combinations of demographic, anthropometric, and fitness variables could increase the risk of re-identification. Requests for access to de-identified participant-level data may be considered subject to ethics and institutional approval. This deposit supports transparency and reproducibility and does not constitute a manuscript preprint.