Installation of a stationary high desk in the workplace: effect of a 6-week intervention on physical activity

BACKGROUND Extended sitting time at work is viewed as a crucial public health issue. Encouraging workers to stand during their office hours via the installation of standing desks maybe one effective option to combat this. Here, we investigate whether the installation of high desks in the workplace can induce positive changes in the amount of physical activity (PA) and thereby lead to subsequent improvements in anthropometric parameters. METHODS Thirty-two white-collar workers (22 men and 10 women, mean age 44.2) were randomly divided into two groups. A randomised crossover trial was performed for 13 weeks. During the experimental period, subjects completed their office work in a standing position using stationary high desks (standing work, SW) for 10 hours per week or more (SW period). The subjects were asked to maintain their normal sitting working habits during the control period (CONT period). The primary outcome was PA, which was assessed objectively using a triaxial accelerometer during weekdays and weekends. The secondary outcomes were anthropometric measurements. For each group and each parameter, the mean values during each period were recorded and were compared by paired t test. RESULTS The daily total PA (10.2 ± 2.4 vs. 9.7 ± 2.3 METs · h/day, P = 0.043), MVPA (4.2 ± 2.2 vs. 3.7 ± 1.8 METs · h/day, P = 0.025), time spent in moderate PA (58.2 ± 20.7 vs. 53.4 ± 17.0 min/day, P = 0.019) and time spent in MVPA (62.8 ± 25.1 vs. 57.0 ± 20.3 min/day, P = 0.019) were significantly higher during the SW period compared to the CONT period. A weekdays verses weekends subanalysis revealed that these parameters were significantly higher during the SW period compared to the CONT period during weekdays only. No significant differences were noted before and after SW periods for most of the anthropometric measures, except waist circumference (83.7 ± 7.9 vs. 83.0 ± 7.9 cm, respectively, P = 0.007). CONCLUSIONS Standing work, via the installation of high desks, significantly increases moderate to vigorous physical activity, especially on weekdays. TRIAL REGISTRATION UMIN-CRT, UMIN000016731, 7th March 2015.