There’s a good chance that just about everyone who works in an office has already heard about the risks sitting for long hours poses to their health (see here, here, here, and here). As society has moved from the field to the office, more of us have adopted sedentary lifestyles, sitting for hours at our desks just to go home and do the same thing in front of the TV. Then recently, treadmill desks (and exercise balls and office cycles) were introduced, ushering in time where we can work and walk — and hopefully prevent obesity and its related diseases. But it turns out that hope might just be in vain, as a new study has found these desks may not be too effective.

It may seem counterintuitive that treadmill desks won’t help a person lose weight, but with a max speed of only 2 miles per hour, anyone using them is only partaking in light intensity physical activity. That’s a problem because national recommendations for physical activity call for two-and-a-half hours of moderate intensity physical activity each week. For the overweight and obese employee participants, the amount of activity they completed on their treadmills desk simply wasn’t enough to burn fat.

Oregon State University researchers believe this lack of intense physical activity, plus logistical problems with getting the desks to employees, are what led them to discover using a treadmill desk for three months did nothing to affect weight or change body mass index — despite employees’ average daily steps rising over 1,000. “Treadmill desks aren’t an effective replacement for regular exercise, and the benefits of the desks may not justify the cost and other challenges that come with implementing them,” said John Schuna, assistant professor of exercise and sports science at the university’s College of Public Health and Human Sciences, in a press release.

Combined with the lack of intensity, the researchers also found it difficult to get employees to participate in the activity. Many claimed a variety of reasons for not getting active, while others couldn’t get a supervisor’s approval. They also faced scheduling conflicts as there were only a limited number of treadmill desks. Altogether, these factors played a big part in failing to get employees motivated to exercise, which was the researchers’ goal — and if you can't get them motivated through programs like these, what are the chances they'll get motivated on their own?

Out of 700 total employees, the researchers were only able to get about 40 to participate in the 12-week study. They split the group in half, with one half using the treadmill desks and the other half serving as a control group. Each participant walked on the treadmill desks for an average of only 45 minutes a day, half the amount of time they were asked to.

Roughly 69 percent of all American adults are either obese or overweight, according to the Centers for Disease Control and Prevention. Getting motivated is one of the hardest parts, and it becomes a lot easier once you get into a routine, but finding out how to get motivated in the first place is key. “We need to identify some form of physical activity that can be done simply and at a low cost in an office setting,” Schuna said. (Maybe some of these can help.)

While treadmill desks may not be best for effective moderate intensity exercise, studies have shown they do well at improving productivity. One such study from last year found supervisors tended to be more satisfied with their employees’ work — based on a 10-point scale — at the end of workweeks spent on the treadmill desks than plainly sitting in a chair. At the same time, employees also rated their productivity higher at the end of weeks they spent time on the treadmill desk. It’s unclear why performance improved, but it might be due to the fact walking kept these people more alert, or maybe they were just paranoid of others looking at their computer screen.

Source: Schuna J, Swift D, Hendrick C, et al. Evaluation of a Workplace Treadmill Desk Intervention: A Randomized Controlled Trial. Journal of Occupational and Environmental Medicine. 2015.