Without question, inactivity is bad for us. Prolonged sitting is consistently linked to higher risks of cardiovascular disease and death. The obvious response to this frightful fate is to not sit—move. Even a few moments of exercise can have benefits, studies suggest. But in our modern times, sitting is hard to avoid, especially at the office. This has led to a range of strategies to get ourselves up, including the rise of standing desks. If you have to be tethered to a desk, at least you can do it while on your feet, the thinking goes.
However, studies on whether standing desks are beneficial have been sparse and sometimes inconclusive. Furthermore, prolonged standing can have its own risks, and data on work-related sitting has also been mixed. While the final verdict on standing desks is still unclear, two studies out this year offer some of the most nuanced evidence yet about the potential benefits and risks of working on your feet.
Take a Seat
For years, studies have pointed to standing desks improving markers for cardiovascular and metabolic health, such as lipid levels, insulin resistance, and arterial flow-mediated dilation (the ability of arteries to widen in response to increased blood flow). But it's unclear how significant those improvements are to averting bad health outcomes, such as heart attacks. One 2018 analysis suggested the benefits might be minor.
And there are fair reasons to be skeptical about standing desks. For one, standing—like sitting—is not moving. If a lack of movement and exercise is the root problem, standing still wouldn't be a solution.
Yet, while sitting and standing can arguably be combined into the single category of “stationary,” some researchers have argued that not all sitting is the same. In a 2018 position paper published in the Journal of Occupational and Environmental Medicine, two health experts argued that the link between poor health and sitting could come down to the specific populations being examined and “the special contribution” of “sitting time at home, for example, the ‘couch potato effect.’”
The two researchers—emeritus professors David Rempel, formerly at the University of California, San Francisco, and Niklas Krause, formerly of UCLA—pointed to several studies looking specifically at occupational sitting time and poor health outcomes, which have arrived at mixed results. For instance, a 2013 analysis did not find a link between sitting at work and cardiovascular disease. Though the study did suggest a link to mortality, the link was only among women. There was also a 2015 study on about 36,500 workers in Japan who were followed for an average of 10 years. That study found that there was no link between mortality and sitting time among salaried workers, professionals, and people who worked at home businesses. However, there was a link between mortality and sitting among people who worked in farming, forestry, and fishing industries.
Still, despite some murkiness in the specifics, more recent studies continue to turn up a link between total prolonged sitting—wherever that sitting occurs—and poor health outcomes, particularly cardiovascular disease. This has kept up interest in standing desks in offices, where people don't always have the luxury of frequent movement breaks. And this, in turn, has kept researchers on their toes to try to answer whether there is any benefit to standing desks.
One study published last month in the International Journal of Epidemiology offers a clearer picture of how standing desks may relate to cardiovascular health risks. The authors, an international team of researchers led by Matthew Ahmadi at the University of Sydney in Australia, found that standing desks don't improve heart health—but they don't harm it, either, whereas sitting desks do.
Mitigating Risks
For the study, the researchers tracked the health data of a little more than 83,000 people in the UK over an average of about seven years. During the study, participants wore a wrist-based accelerometer device for at least four days. The devices were calibrated to determine when they were sitting, standing, walking, or running during the waking hours. With that data, the researchers linked their sitting, standing, and stationary (combined sitting and standing) times to health outcomes in their medical records.
The researchers focused on two categories of health outcomes: cardiovascular, covering coronary heart disease, heart failure, and stroke; and orthostatic circulatory disease events, including orthostatic hypotension (blood pressure drops upon standing or sitting), varicose veins, chronic venous insufficiency (veins in your legs don't move blood back up to your heart), and venous ulcers. The reasoning for this second category is that prolonged sitting and standing may pose risks for developing circulatory diseases.
The researchers found that when participants' total stationary time (sitting and standing) was more than 12 hours per day, risk of orthostatic circulatory disease increased 22 percent per additional hour, while risk of cardiovascular disease went up 13 percent per hour.
For just sitting, risks increased every hour after 10 hours: For orthostatic circulatory disease, risk went up 26 percent every hour after 10 hours, and cardiovascular disease risk went up 15 percent. For standing, risk of orthostatic circulatory disease went up after just two hours, increasing 11 percent every 30 minutes after two hours of standing. But standing had no impact on cardiovascular disease at any time point.
“Contrary to sitting time, more time spent standing was not associated with a higher CVD [cardiovascular disease] risk. Overall, there was no association for higher or lower CVD risk throughout the range of standing duration,” the authors report.
On the other hand, keeping sitting time under 10 hours and standing time under two hours was linked to a weak protective effect against orthostatic circulatory disease: A day of nine hours of sitting and 1.5 of standing (for a total of 11.5 hours of stationary time) lowered risk of orthostatic circulatory disease by a few percentage points, the study found.
In other words, as long as you can keep your total stationary time under 12 hours, you can use a little standing time to help you keep your sitting time under 10 hours and avoid increasing both cardiovascular and orthostatic risks, according to the data.
Consistent Finding
It's a very detailed formula to reduce the health risks of long days at the office, but is it set in stone? Probably not. For one thing, it's just one study that needs to be replicated in a different population. Also, the study didn't look at any specifics of occupational versus leisure standing and sitting times, let alone the use of standing desks specifically. The study also based estimates of people's sitting, standing, and total stationary time on as little as just four days of activity monitoring, which may or may not have been consistent over the nearly seven-year average follow-up period.
Still, the study's takeaway generally fits with a study published in January in JAMA Network Open. This study looked at the link between occupational sitting time, leisure physical activity, and death rates—both deaths from all causes and those specifically caused by cardiovascular disease. Researchers used a group of more than 480,000 workers in Taiwan, who were followed for an average of nearly 13 years.
The workers who reported mostly sitting at work had a 16 percent increased risk of all-cause mortality and a 34 percent higher risk of dying from cardiovascular disease compared with workers who did not sit at work. The workers who reported alternating between sitting and standing, meanwhile, did not have an increased risk of all-cause or cardiovascular disease mortality. The findings held after adjusting for health factors and looking at subgroups, including by sex, age, smokers, never-smokers, and people with chronic conditions.
That said, being highly active in leisure time appeared to offset the mortality risks among those who mostly sit at work. At the highest leisure-time activity levels reported, participants who mostly sit at work had comparable risks of all-cause mortality as those who alternated sitting and standing or who didn't sit at work. Overall, the data suggested that keeping overall stationary time as low as possible and alternating sitting and standing to some extent at work can reduce risk.
The authors call for incorporating breaks in work settings and even specifically recommend allowing for standing and activity-permissive workstations.
The Takeaway
While prolonged standing has its own risks, the use of standing desks at work can, to some extent, help lessen the risks of prolonged sitting. But, overall, it's important to keep total stationary time as low as possible and exercise whenever possible.
This story originally appeared on Ars Technica.
