Physical activity and leg strength predict decline in mobility performance in older persons

Area of Science:

• Gerontology
• Kinesiology
• Public Health

Background:

• Mobility decline is a significant concern for older adults, impacting independence and quality of life.
• Identifying modifiable factors like physical activity and leg strength is crucial for interventions.

Purpose of the Study:

• To investigate the association between physical activity, leg strength, and the rate of mobility change in older persons.
• To determine if these factors independently predict mobility decline.

Main Methods:

• Prospective, observational cohort study of 886 ambulatory older adults without dementia.
• Assessed physical activity levels and leg strength at baseline.
• Measured the rate of change in mobility over time using linear mixed-effects models.

Main Results:

• Higher physical activity was associated with a slower rate of mobility decline (approx. 3% decrease per hour of activity).
• Greater leg strength was also linked to a slower rate of mobility decline (approx. 20% decrease per unit of strength).
• Both physical activity and leg strength remained significant predictors of mobility even after adjusting for numerous health factors.

Conclusions:

• Physical activity and leg strength are independent predictors of mobility decline in older adults.
• While physical activity may enhance strength, its positive impact on mobility likely involves additional mechanisms.
• These findings highlight the importance of promoting both exercise and strength training for maintaining mobility in aging populations.