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Ten-Year Changes in Accelerometer-Based Physical Activity and Sedentary Time During Midlife: The CARDIA Study
Kelley Pettee Gabriel1,2, Stephen Sidney3, David R Jacobs4
1Department of Epidemiology, Human Genetics, and Environmental Sciences and Michael & Susan Dell Center for Healthy Living, UTHealth School of Public Health, Austin Campus, Austin, Texas.
American Journal of Epidemiology
|June 13, 2018
Summary
Midlife adults experienced significant declines in physical activity (PA) and increases in sedentary time over ten years. Black men showed the most substantial PA reductions, highlighting the need for targeted interventions.
Area of Science:
- Epidemiology
- Public Health
- Gerontology
Background:
- Midlife is a critical period for lifestyle changes impacting long-term health.
- Understanding changes in physical activity (PA) and sedentary time across diverse demographic groups is crucial for public health.
- Previous research has not fully detailed PA and sedentary time shifts within specific race and sex strata during midlife.
Purpose of the Study:
- To examine 10-year changes in accelerometer-determined physical activity (PA) and sedentary time.
- To investigate these changes within and across race and sex groups in a midlife cohort.
- To identify demographic differences in PA and sedentary time trajectories during midlife.
Main Methods:
- Utilized data from the Coronary Artery Risk Development in Young Adults (CARDIA) Study, a midlife cohort.
- Participants (n=962) wore accelerometers at baseline (ages 38-50) and 10-year follow-up (ages 48-60).
- Data were calibrated for accelerometer model differences, and analyses accounted for race and sex stratification.
Main Results:
- Overall accelerometer counts decreased significantly (-65.5 counts/min/day), as did light-intensity PA (-30.6 min/day) and moderate- to vigorous-intensity PA (-7.5 min/day).
- Sedentary time significantly increased overall (+37.9 min/day).
- Black men exhibited the most pronounced declines in PA compared to other race and sex groups, with significant differences noted across all measured PA metrics.
Conclusions:
- Midlife is associated with substantial declines in physical activity and increases in sedentary behavior across all demographic groups studied.
- These PA declines are characterized by a shift from light-intensity activities to increased sedentary time, potentially posing health risks.
- Targeted public health interventions are necessary to promote and preserve physical activity across all intensity levels throughout midlife, with special attention to vulnerable groups like Black men.
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