Impact of Sit–Stand Desks on Subjective Sitting Time and Psychological Outcomes in Office Workers: Findings from the Stand Up for Healthy Ageing (SUFHA) Randomized Controlled Trial

Objective: – Prolonged sitting is a major risk factor for adverse health outcomes, even among physically active individuals. This study evaluated the effectiveness of a 6-month sit–stand desk intervention in reducing sitting time and improving psychological outcomes in office workers. Methods: – A clustered randomized controlled trial was conducted with 38 office workers, allocated to either a sit–stand desk intervention or a traditional desk control group. Outcomes were assessed using validated self-report questionnaires. Results: – A significant group-by-time interaction favoring the intervention group was observed for weekday sitting time, which decreased from 8.00 to 5.22 h/day (P = 0.03), but not during weekends. No significant between-group differences were found for psychological outcomes, though exploratory analyses highlighted potential predictors explaining the reductions in sitting time. Conclusions: – Sit–stand desks reduced occupational sitting time, suggesting potential value for workplace health interventions. Clinical trial registration: – The trial was prospectively registered at Open Science Framework Registries (Registration DOI: 10.17605/OSF.IO/JHGPW). Registered November 16, 2022. Copyright © 2026 American College of Occupational and Environmental Medicine.