Beneficial, adverse, and spiraling health-promotion effects: Evidence from a longitudinal randomized controlled trial of working at sit–stand desks.

In a 6-month longitudinal randomized field experiment, we examined how using height-adjustable sit-stand desks could have beneficial, adverse, and spiraling effects on people's musculoskeletal and psychovegetative complaints, and on positive (vitality and vigilance) and negative psychological symptoms, namely, stressor uncontrollability (i.e., perceived uncontrollability of workload), psychological tension, and mental tiredness. A total of 127...