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..
..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).
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.