The popular sit-stand computer desks for office workers not only reduce daily sitting time – which has been linked to high blood pressure, excess body fat, and heart disease – they also appear to have a positive impact on employees' job performance and psychological health.

On average, sedentary office workers spend about 70 percent to 85 percent of the workday in their chairs. But researchers in England found that workers who used the up-and-down computer platforms spent about an hour less each day sitting. The results were published Wednesday in the BMJ medical journal.

The study divided a group of 146 office workers at the University Hospitals of Leicester NHS Trust into two groups. One group was given height-adjustable work stations while the other group used traditional sitting desks. About 80 percent of the participants were women, and the average age was 41. Researchers followed the groups for about a year.

The group with the sit-stand desks also were given work-station instructions, feedback on physical activity, goal-setting, and a prompt tool for standing. Their sitting time was measured at the beginning of the study and at three months, six months, and a year into the study. Daily physical activity levels were recorded, and employees were asked questions about job performance and work engagement, as well as mood and quality of life.

At the start of the study, the intervention group reported sitting about 9.7 hours a day. As the study progressed, their sitting time was reduced by about 51 minutes at the three-month mark, 64 minutes at six months, and 82 minutes after a year.

The sit-stand workers reported improvements in job performance, work engagement, occupational fatigue, daily anxiety, and quality of life. Job satisfaction, problem solving, and taking time off while ill did not change, according to the study.

Researchers suggested that future studies look at how to promote movement and not just standing while working.