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Design and Evaluation of Smart Glasses for Food Intake and Physical Activity Classification
Published on: February 14, 2018
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Active-to-Sedentary Behavior Transitions, Fatigability, and Physical Functioning in Older Adults
Jennifer A Schrack1,2,3, Pei-Lun Kuo1,3, Amal A Wanigatunga1,2
1Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland.
Summary
Fragmented physical activity (PA), measured by Active-to-Sedentary Transition Probability (ASTP), is linked to poorer physical function in older adults. Higher ASTP indicates more fragmented PA and is associated with slower gait, increased fatigability, and reduced performance.
Area of Science:
- Gerontology
- Exercise Physiology
- Public Health
Background:
- Daily physical activity (PA) often decreases and becomes more fragmented with aging.
- Understanding PA accumulation patterns, including transitions from active to sedentary behaviors, is crucial for assessing functional status in older, less active individuals.
Purpose of the Study:
- To investigate the association between the Active-to-Sedentary Transition Probability (ASTP) and key measures of physical function in older adults.
- To determine if ASTP provides additional insights into functional status beyond total daily PA.
Main Methods:
- The study analyzed data from 680 participants (aged 27-94 years) in the Baltimore Longitudinal Study of Aging.
- Active-to-Sedentary Transition Probability (ASTP) was calculated as the reciprocal of average PA bout duration.
- Associations between ASTP and gait speed, fatigability, 400 m time, and physical performance scores were examined using regression analyses, adjusted for chronic conditions.
Main Results:
- Higher ASTP was significantly associated with slower gait speed, increased fatigability, longer 400 m walk times, and lower physical performance scores.
- Individuals in the highest tertile of ASTP were more likely to experience high fatigability and reduced functional performance compared to those in the lowest tertile.
- ASTP offered additional predictive value for functional outcomes compared to total daily PA alone.
Conclusions:
- Fragmented physical activity, quantified by ASTP, is strongly associated with poorer health and functional status in older adults.
- ASTP may serve as a valuable metric for identifying individuals at risk of high fatigability and functional decline.
- This metric provides insights beyond traditional PA measures for assessing physical function in aging populations.
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