Association of Timing of Physical Activity with Physical Frailty Incidence in Older Adults.

INTRODUCTION

Maximizing the benefits of physical activity (PA) is important to prevent physical frailty for a measure of this public health issue. This study aimed to investigate the association of timing of PA with the conversion to physical frailty.

METHODS

This longitudinal observational study enrolled a total of 1,310 community-dwelling Japanese older adults who enrolled in the National Center for Geriatric and Gerontology-Study of Geriatric Syndromes remained as the examined population. A health checkup was conducted to measure baseline characteristics. Subsequently, objectively measured PA was recorded for ≥7 days (≥10 h per day) for 30 days. Daily steps and the morning (6:00-12:00), afternoon (12:00-18:00), and evening (18:00-24:00) steps were calculated. A 2-year follow-up survey was administered to determine the frailty conversion, defined by newly acquired Kihon Checklist scores of 7 or higher. A logistic regression model was constructed with timing of PA and covariates as explanatory variables and frailty conversion as the dependent variable.

RESULTS

The number of conversions to frailty was 121 (9.2%). A significant association were observed between evening steps and frailty conversion (log(OR) = -0.44; 95% confidence interval [CI] = -0.87 to 0.03; p = 0.037). No significant associations were observed in the PA of morning (log(OR) = -0.03; 95% CI = -0.51 to 0.55; p = 0.906) and afternoon (log(OR) = -0.36; 95% CI = -0.78 to 0.13; p = 0.117).

CONCLUSIONS

Evening PA could be advantageous in preventing frailty conversion among community-dwelling older adults. Maximizing the impact of PA may be effective against this public health concern, physical frailty.