If there’s anything scientists know about the best type of desk for an office worker’s long-term health, it’s that they don’t really know anything, according to a new analysis of the scientific literature on the matter.

After closely examining 20 of the highest quality studies about workplace interventions to reduce sitting time, which include standing, pedaling, and treadmill desks, researchers concluded that there simply isn’t enough data to say whether any of the alternatives are better that just plopping in front of a standard desk.

A number of studies in the past had found that planting your bum in an office chair for hours at a time can up your chances of heart failure, disabilities, and even shorten your life. Collectively, the data spurred a trend for alternative workstations that are aimed at reversing those negative effects, boosting calorie burning, and improving overall health.

But the reviewers say it’s unclear if such solutions make the mark. To-date, the studies on the alternatives did show that they can cut down on 30 minutes-to-two hours’ worth of sitting time. But all of the studies have been too small and/or poorly designed to definitely give an answer on whether that has an impact on health, the researchers report in the Cochrane Database of Systematic Reviews. The studies included a total of only 2174 participants, rarely had randomized controls, and only followed health outcomes for up to six months.

"What we actually found is that most of it is, very much, just fashionable and not proven good for your health," Jos Verbeek, a review coauthor and health researcher at the Finnish Institute of Occupational Health, told NPR.

"The idea you should be standing four hours a day? There's no real evidence for that," he added. "I would say that there's evidence that standing can be bad for your health." For instance, an earlier study found that standing for long periods may increase the risk for needing medical attention for enlarged veins.

While the authors urge that more, high-quality studies are needed to evaluate the health impacts of different workstations, they concluded so far: