Impact of sit-stand desks on subjective sitting time and psychological outcomes in office workers: findings from the 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 six-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 favouring 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.