Abstract
BACKGROUND: Sedentary behaviors are pervasive in children. We found acute 3-h improvements in metabolic and affective outcomes by interrupting sitting. It is unknown whether acute responses translate to sustained or improved responses over multiple days. This paper describes the rationale, study design, recruitment, data collection, and data analytic protocols for the Sedentary Behavior Study 3 (SBS3). METHODS: This is a 3-arm parallel-group randomized controlled trial of N = 150 (50 per group) 8-11-year-old children with overweight/obesity. Following screening and 7-10 day baseline free-living assessment, children are randomly assigned to complete one of three in-lab conditions for 3 h/day for 7 consecutive days: (1) continuous sitting (SIT); (2) sitting interrupted by 3-min bouts of moderate-intensity walking every 30 min (SIT+WALK); or (3) a single 18-min bout of moderate-intensity walking followed by continuous sitting (EX). Three-hour oral glucose tolerance tests are conducted on Days 1 and 7. Participants also wear continuous glucose monitors and accelerometers for the duration of the study, and complete daily 24-h dietary recalls and affective assessments. CONCLUSIONS: The overall aim of this study is to evaluate the effectiveness of interrupting sitting over one week on glucose homeostasis (primary outcome) and secondary (cognitive and affective) outcomes in children. If successful, it will provide novel intervention strategies that can be translated to other settings, and age and weight groups, thereby contributing to efforts at reducing type 2 diabetes risk in U.S. youth. TRIAL REGISTRATION: ClinicalTrials.govNCT04469790, registered July 14, 2020.