Fast walking and physical activity are independent contributors to improved physical function

Area of Science:

• Gerontology
• Public Health
• Epidemiology

Background:

• Functional disability poses a significant challenge to aging populations worldwide.
• Identifying modifiable risk factors is essential for developing effective prevention strategies.
• Physical activity and walking speed are potential targets for intervention.

Purpose of the Study:

• To investigate the independent associations of fast walking and habitual physical activity with the incidence of functional disability.
• To explore how these associations differ across age groups.

Main Methods:

• A historical cohort study involving 9,652 Japanese adults (aged 39-98) without baseline functional disability.
• Functional disability assessed via the Japanese long-term care insurance system.
• Cox proportional hazards models used to analyze the impact of walking speed and physical activity on disability incidence over a median 3.7-year follow-up.

Main Results:

• Lack of habitual physical activity (HR 1.56) and slow walking speed (HR 1.89) were independent predictors of increased functional disability risk.
• The impact of physical activity on disability was more pronounced in individuals aged 75 and older.
• Slow walking speed significantly increased disability risk in individuals younger than 75, irrespective of physical activity habits.

Conclusions:

• Both a lack of physical activity habit and slow walking speed are independent risk factors for incident functional disability in the Japanese population.
• The relative importance of these factors in predicting functional disability is age-dependent.