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

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.

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.

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.

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.

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.