Domain-Specific Physical Activity and Its Association With Frailty Syndrome: Evidence From NHANES Using Phenotype and...

Frailty syndrome is a common age-related condition associated with increased risks of disability, hospitalization, and mortality. Although physical activity (PA) is a modifiable lifestyle factor, limited research has explored how specific PA domains relate to frailty using validated multidimensional models. This study aimed to examine the associations between 4 PA domains-total PA, occupational PA (OPA), transport-related PA (TPA), and leisure-time PA (LTPA)-and frailty syndrome, as assessed by both the frailty phenotype (FP) and frailty index (FI) models in a nationally representative U.S.

We analyzed data from 59 842 adults who participated in 6 cycles of the National Health and Nutrition Examination Survey (NHANES, 2007-2018). PA levels were self-reported and categorized by weekly duration based on guideline adherence (≥ 150 min/week) and distribution quartiles. Frailty was independently assessed using FP and FI models. Multivariable linear regression, subgroup, sensitivity analysis, and dose-response analyses were conducted.

Higher levels of total PA and LTPA were consistently associated with lower frailty scores in both FP and FI models. The strongest inverse associations were observed for LTPA ≥ 300 min/week. In contrast, OPA and TPA showed limited or no associations after adjustment for confounders. Subgroup and sensitivity analyses supported these findings, with particularly pronounced effects among older adults (≥ 80 years) and women.

LTPA demonstrated the strongest associations with lower frailty, highlighting its potential as a key target for preventive strategies and public health guidelines aimed at promoting healthy aging.