Daily Physical Activity Predicts Frailty Development Among Community-Dwelling Older Japanese Adults

Objectives: This study examined the association between frailty development and physical activity including the number of steps, the time of light-intensity physical activity (LPA) with <3.0 metabolic equivalents (METs), and the time of moderate- to vigorous-intensity physical activity (MVPA) with ≥3.0 METs in community-dwelling older Japanese adults.

Design, setting, and participants: Study subjects were 401 older adults at the baseline examination (April 2000-May 2002) who participated at least once in the follow-up examination of the longitudinal study of aging. Their 1787 cumulative data points (mean number of repeat visits, 3.5) were used for analysis.

Measures: The number of steps, time of LPA, and time of MVPA were recorded at baseline using a uniaxial accelerometer. Frailty was defined according to 5 frailty criteria: shrinking, exhaustion, low physical activity, low grip strength, and slow gait speed.

Results: The fully adjusted odds ratio for frailty among subjects walking <5000 steps was 1.85 [95% confidence interval (CI), 1.10-3.11]. The fully adjusted odds ratio for frailty among subjects with MVPA for <7.5 minutes was 1.80 (95% CI, 1.05-3.09). No significant association was observed between frailty and LPA.

Conclusions and implications: The risk for developing frailty was substantially lower in older people walking ≥5000 steps/d or exercising for at least 7.5 minutes/d at an intensity >3.0 METs. These data could be applicable to the community interventions that aim to prevent frailty.