The Seated Inactivity Trial (SIT): Physical Activity and Dietary Outcomes Associated With 8 Weeks of Imposed Sedentary Time

in Journal of Physical Activity and Health
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Sedentary time is an independent risk factor for chronic diseases and mortality. It is unknown whether active adults alter their dietary and/or physical activity behaviors in response to imposed sedentary time, possibly modifying risk. The aim of this study was to determine whether imposed sedentary time would alter typical behaviors of active adults.


Sixteen physically active, young adults were randomized to the no-intervention control (CON, n = 8) group or the sedentary-intervention (SIT, n = 8) group. SIT participants attended monitored sedentary sessions (8 wk, 10 h/wk). Assessments including diet and physical activity occurred at baseline, week 4, and week 9.


There were no differences (P > .05) between CON and SIT groups for step counts or time spent in sedentary, light, moderate, or vigorous physical activity when comparing a week during imposed sedentary time (week 4) to baseline and week 9. At week 4, caloric intake was not different from baseline (P > .05) in either group. Caloric intake decreased significantly (P > .05) in SIT from baseline to week 9.


Active adults did not alter physical activity or dietary behaviors during the imposed sedentary intervention. However, SIT reduced caloric intake from baseline to week 9, indicating a possible compensatory response to imposed sitting in active adults.

The authors are with the Dept of Food, Nutrition, Dietetics and Health, Kansas State University, Manhattan, KS. Cull ( is corresponding author.