We know that physical activity is good for us and that being sedentary is not. Some have extrapolated this to mean that sitting, in general, is something to be avoided, even at work. Perhaps as a result, standing desks have become trendy and are promoted by some health officials, as well as some countries.

Research, however, suggests that warnings about sitting at work are overblown and that standing desks are overrated as a way to improve health.

David Rempel, a professor of medicine at the University of California, San Francisco, who has written on this issue, said, “Well-meaning safety professionals and some office furniture manufacturers are pushing sit-stand workstations as a way of improving cardiovascular health — but there is no scientific evidence to support this recommendation.”

For convenience and comfort, it is nice to have options if you have various aches and pains — “Alternating standing and sitting while using a computer may be useful for some people with low back or neck pain,” he said — but people should not be under the illusion that they are getting exercise.

A number of studies have found a significant association between prolonged sitting time over a 24-hour period and increased risk for cardiovascular disease. A 2015 study followed more than 150,000 older adults — all of whom were healthy at the start of the study — for nearly seven years on average. Researchers found that those who sat at least 12 hours a day had significantly higher mortality than those who sat for less than five hours per day.

A 2012 study in JAMA Internal Medicine followed more than 220,000 people for 2.8 years on average and found similar results. Prolonged sitting over the course of a day was associated with increased all-cause mortality across sexes, ages and body mass index. So did a smaller but longer (8.6 years on average) study published in 2015 in the Journal of Physical Activity & Health.

Another study from 2015, which followed more than 50,000 adults for more than three years, also found this relationship. But it found that context mattered. Prolonged sitting in certain situations — including when people were at work — did not have this same effect.

Why might that be? Sitting itself may not be the problem; it may be a marker for other risk factors that would be associated with higher mortality. Unemployed or poorer people, who would also be more likely to have higher mortality, may be more likely to spend large amounts of time sitting at home. For some, sedentary time is a marker, not the cause, of bad outcomes.

Studies looking specifically at work do not find a causal pattern. One 2015 paper focused on workers age 50 to 74 in Japan, for more than 10 years on average per participant. It found that — among salaried workers, professionals and those in home businesses — there was no association between sitting at work and cardiovascular risk. A 2016 study examining Danish workers also failed to find a link.

A systematic review published in the American Journal of Preventive Medicine found that there were many studies that identified associations with sitting at work and poor health outcomes. But when they focused on prospective studies — following groups of people forward over time — which might better confirm a causal link, they found that there was not really much evidence to support it.

Moreover, these studies tend to focus only on the positive effects of standing at work and the negative effects of sitting. A full accounting would also examine the opposite. A longitudinal study of more than 38,000 people published in the journal Occupational and Environmental Medicine found that standing or walking for more than six hours a day at work was associated with a doubled or tripled risk of needing surgery for varicose veins. Varicose veins are also associated with increased risks of arterial disease and heart failure.

It is possible, though, that standing at work — as with sitting too much at home — could be a marker for other unhealthy demographic factors or habits, including lower socioeconomic status. There is a difference between those who must stand or walk for most of the workday and those who can sit at any time.

But particularly for those who do not have the option to lower their desk, there is at least some evidence in that study and in others that standing for much of a workday is not healthful.

A number of countries have called for more standing and less sitting at work. Some go as far as to declare “sitting is the new smoking.” In 2013, an American Medical Association board member said, “Prolonged sitting, particularly in work settings, can cause health problems, and encouraging workplaces to offer employees alternatives to sitting all day will help to create a healthier workforce,” and suggested that standing work stations should be one of the options.

Too much sitting over the course of a day is not healthy — let’s be clear. And as I have written before, exercise is the closest thing to a wonder drug. Few things provide as much health benefits.

But standing is not exercise. Many health groups recommend that people at work take frequent walking breaks. Replacing sitting with standing does not fulfill that recommendation and may even mislead people into thinking they are doing enough activity.

Sit-stand desks are not exactly inexpensive, but like many things in life, they are fine if you like them. And if it helps alleviate some back and neck pain, so much the better. It is just that most people probably do not need them.