Harvard study links smartwatch activity patterns to biological aging

Researchers from the Harvard T. H. Chan School of Public Health have identified that continuous activity patterns recorded by smartwatches can provide useful signals related to biological aging. A study published in Nature Communications analyzed data from 2,222 participants in the All of Us program who shared Fitbit device data.

The study examined various metrics, including daily activity intensity, regularity, fragmentation, and peak activity times. Researchers compared these patterns against PhenoAge, a phenotypic marker calculated using chronological age and nine clinical measures such as glucose, creatinine, and C-reactive protein.

Findings indicated that more intense activity rhythms were associated with a lower probability of accelerated aging. Conversely, activity concentrated later in the day appeared to be associated with a higher probability of accelerated aging in the longitudinal model. The researchers noted that while smartwatches do not diagnose or calculate biological age on their own, the data they collect can help identify significant aging markers. The study is observational and does not establish direct cause and effect.