Data and analysis code for: Apparent training-load effects on wellness are not robust in a full-season audit of one elite footballer

De-identified analysis dataset and complete analysis code (Python and R) that reproduce all statistical results, tables, and figures reported in the manuscript "Apparent training-load effects on wellness are not robust in a full-season audit of one elite footballer" (single-athlete observational study). The package contains no participant, club, opponent, or other identifying information. Raw device-level monitoring data are not included because they are owned by the football club and could identify the athlete. Contents: repro_dataset.csv (N=180 regression sample), repro_dataset_gam.csv (N=184 bivariate sample), repro_analysis.py (specification-sensitivity, month-adjusted OLS-HAC, and alternative-inference sensitivity), repro_gam.R (GAM non-linearity check), and README.txt.