Frequent Versus Single Active Bouts Differentially Affect Movement Behavior and Energy Balance in Adults With Overweight/Obesity

ABSTRACT Objective This study aimed to investigate the effects of breaking up sedentary behavior (SB) on daily movement behavior and energy balance in adults with overweight/obesity. Methods Thirty participants (16F/14M; 34.2 ± 7.3 years; 29.5 ± 3.2 kg/m 2 ) were randomized to either BREAK (multiple 5‐min brisk walking bouts) or a duration‐matched intervention, ONE (45‐min brisk walking), performed 5 days/week for 6 weeks. At pre‐ and post‐intervention, daily SB and physical activity (PA; accelerometry), body composition (doubly labeled water [DLW]), total daily energy expenditure (TDEE; DLW), appetite, and fasting leptin were measured. Linear mixed‐effects models tested time effects and group‐by‐time interactions. Results Only BREAK reduced prolonged SB (interaction: p  = 0.043). Both groups shifted SB‐PA composition toward greater moderate‐to‐vigorous PA, with proportional reductions in SB and light PA (time: all p  ≤ 0.011). These changes in PA level were associated with increased TDEE (time: p  = 0.040). ONE showed small increases in body and fat mass compared with BREAK (interaction: both p  ≤ 0.061). No differences were noted in metabolizable energy intake, appetite, or leptin levels. Conclusions Spreading short PA bouts throughout the day increases moderate‐to‐vigorous PA and TDEE to the same extent as a traditional continuous PA bout. Future studies should investigate whether the modest body composition changes observed across interventions are driven by distinct behavioral/physiological compensations influenced by the daily pattern of PA/SB. Trial Registration ClinicalTrials.gov : NCT02998892