Jacob D Meyer1, Laura D Ellingson2, Matthew P Buman3, Robin P Shook4, Gregory A Hand5, Steven N Blair6. 1. Department of Kinesiology, Iowa State University, Ames, Iowa. Electronic address: jdmeyer3@iastate.edu. 2. Division of Health and Exercise Science, Western Oregon University, Monmouth, Oregon. 3. College of Health Solutions, Arizona State University, Tempe, Arizona. 4. Department of Pediatrics, Children's Mercy Hospital, Kansas City, Missouri. 5. Department of Epidemiology, West Virginia University, Morgantown, West Virginia. 6. Department of Exercise Science, University of South Carolina, Colombia, South Carolina.
Abstract
INTRODUCTION: Sedentary time is inversely associated with health. Capturing 24 hours of behavior (i.e., sleep, sedentary, light physical activity, and moderate-to-vigorous physical activity) is necessary to understand behavior-health associations. METHODS: Healthy young adults aged 20-35 years (n=423) completed the Profile of Mood States, the Perceived Stress Scale, and dual-energy x-ray absorptiometry and anthropometric measures at baseline and 12 months. Time spent sedentary (total, in prolonged [>30 minutes] and short [≤30 minutes] bouts), in light physical activity (1.5-3.0 METs), moderate-to-vigorous physical activity (>3.0 METs), and asleep, were assessed through SenseWear armband worn 24 hours/day for 10 days at baseline. Isotemporal substitution modeling evaluated cross-sectional and longitudinal psychological and physical health associations of substituting sedentary time with sleep, light physical activity, or moderate-to-vigorous physical activity. Data were collected from 2010 to 2015 and analyzed in 2019. RESULTS: Cross-sectional analyses revealed substituting prolonged sedentary time for sleep was associated with lower stress (standardized β= -0.11), better mood (-0.12), and lower BMI (-0.10). Substituting total or prolonged sedentary for moderate-to-vigorous physical activity was associated with lower body fat percentage (total, -0.22; prolonged, -0.23) and BMI (-0.40; -0.42). Higher BMI was associated with substituting total or prolonged sedentary for light physical activity (0.15; 0.17); lower BMI with substituting prolonged sedentary for short bouts (-0.09). Prospective analyses indicated substituting total or prolonged sedentary with light physical activity was associated with improved mood (-0.16; -0.14) and lower BMI (-0.15; -0.16); substituting with moderate-to-vigorous physical activity was associated with improved mood (-0.15; -0.15). CONCLUSIONS: Short- and long-term psychological benefits may result from transitioning sedentary time to light physical activity or sleep, whereas increasing moderate-to-vigorous physical activity may be required to influence physical health. TRIAL REGISTRATION: This study is registered at www.clinicaltrials.gov NCT01746186.
INTRODUCTION: Sedentary time is inversely associated with health. Capturing 24 hours of behavior (i.e., sleep, sedentary, light physical activity, and moderate-to-vigorous physical activity) is necessary to understand behavior-health associations. METHODS: Healthy young adults aged 20-35 years (n=423) completed the Profile of Mood States, the Perceived Stress Scale, and dual-energy x-ray absorptiometry and anthropometric measures at baseline and 12 months. Time spent sedentary (total, in prolonged [>30 minutes] and short [≤30 minutes] bouts), in light physical activity (1.5-3.0 METs), moderate-to-vigorous physical activity (>3.0 METs), and asleep, were assessed through SenseWear armband worn 24 hours/day for 10 days at baseline. Isotemporal substitution modeling evaluated cross-sectional and longitudinal psychological and physical health associations of substituting sedentary time with sleep, light physical activity, or moderate-to-vigorous physical activity. Data were collected from 2010 to 2015 and analyzed in 2019. RESULTS: Cross-sectional analyses revealed substituting prolonged sedentary time for sleep was associated with lower stress (standardized β= -0.11), better mood (-0.12), and lower BMI (-0.10). Substituting total or prolonged sedentary for moderate-to-vigorous physical activity was associated with lower body fat percentage (total, -0.22; prolonged, -0.23) and BMI (-0.40; -0.42). Higher BMI was associated with substituting total or prolonged sedentary for light physical activity (0.15; 0.17); lower BMI with substituting prolonged sedentary for short bouts (-0.09). Prospective analyses indicated substituting total or prolonged sedentary with light physical activity was associated with improved mood (-0.16; -0.14) and lower BMI (-0.15; -0.16); substituting with moderate-to-vigorous physical activity was associated with improved mood (-0.15; -0.15). CONCLUSIONS: Short- and long-term psychological benefits may result from transitioning sedentary time to light physical activity or sleep, whereas increasing moderate-to-vigorous physical activity may be required to influence physical health. TRIAL REGISTRATION: This study is registered at www.clinicaltrials.gov NCT01746186.