Wearable Data Predicts Cardiorespiratory Fitness Accurately

A systematic review and meta-analysis (search through July 27, 2024) evaluated models estimating cardiorespiratory fitness (CRF) from continuous free-living wearable data, including 18 studies and 31,072 participants. The pooled correlation between predicted and measured CRF was 0.83 (95% CI 0.77–0.88), but heterogeneity was high (I2=97%) and most studies lacked external validation, limiting immediate clinical adoption.