Popular wisdom says that humans spend about one-third of their lives sleeping, but how much of the other two-thirds do we spend off our feet? Sitting isn’t even particularly fun, and its detriments are sometimes compared to those of smoking. Of all the fun things that are evidenced to shorten one’s lifespan, sitting is among the more mundane.
The question becomes: Just how much (or little) movement counteracts the scourge of sitting? Researchers have investigated how different lengths of sedentary time, frequency of movement, and length of movement impact health. They’re starting to find conclusive results on daily movement practices that balance time in a chair.
Science in action — According to one 2019 study, any period of sitting for longer than 30 minutes increases the risk of death, and any amount of exercise — light or vigorous — counters that risk by at least 17 percent. This study, published in the American Journal of Epidemiology, assessed data on nearly 8,000 adults 45 or older from a prior survey, the Reasons for Geographic and Racial Differences in Stroke (REGARDS).
Researchers from New York, Michigan, Arizona, and Alabama institutions analyzed the differences between 30 minutes of light-intensity exercise (e.g., walking at a normal pace) and 30 minutes of moderate-to-vigorous exercise (e.g., jogging or running). They also looked at how outcomes changed when the total sitting time was split up into shorter sessions rather than just one big marathon sit.
The results indicated that replacing 30 minutes of sitting with 30 minutes of any kind of movement decreased the risk of death. A half hour of light-intensity exercise lowered the risk by 17 percent, and a half hour of moderate-to-vigorous exercise brought it down by 34 percent.
“The key here is it’s about interrupting those long periods,” the study’s lead author and professor of exercise physiology at Columbia University, Keith Diaz, tells Inverse. “But it’s also about lowering your overall volume of sitting.”
The more movement, the lower the risk, but even just one minute of exercise cuts into how much sitting you’re doing.
Why it’s a hack — There’s a surprising array of health risks that come with something so quotidian, but Diaz focuses on the damage sitting does to our muscles, glucose levels, and blood pressure.
While our muscles keep us mobile, they also help regulate glucose and fat levels in the blood. If we don’t move after consuming calories, the muscles won’t utilize blood sugar and it will instead get stored. Likewise, if the muscles don’t get regular exercise, they’re less effective at ridding the blood of fat. To boot, too much sitting can decrease muscle mass and strength.
Particularly when it comes to sitting, blood pools in the feet. As a result, pressure builds in the lower legs and harms the blood vessels, which can lead to permanent damage. This also is a drawback for standing desks, which activate the leg muscles but don’t promote circulation the way walking does.
The thing is, even if someone exercises in the morning, a day of sitting will still have adverse effects, Diaz says. The key is to limit sitting time. Even one minute of movement every half hour can do the trick. “Your muscles need exercise snacks,” Diaz tells Inverse. These bite-sized movement breaks don’t have to be a full Zumba session; they could be a few moments of cleaning or vacuuming. These exercise snacks help regularly activate the muscles for them to operate effectively and keep blood flowing throughout the body.
Diaz also gives a shoutout to the small stimulation from fidgeting, like changing sitting positions and shaking legs. He says there’s “early promising research” on how it offsets some harms of sitting and at least gets the blood flowing in some extremities.
The benefits aren’t purely physical. Nicole Culos-Reed, a health and exercise psychology professor at the University of Calgary, stresses how movement benefits mental health too.
“You’d be amazed how many people have shallow breathing all day long because they’re stressed out,” she tells Inverse. Going for a short walk instead of eating lunch at one’s desk can provide an opportunity to breathe more deeply and instill a sense of control and calm.
How it affects longevity — The trick is to both incorporate movement and reduce time sitting, the two researchers say. Excess sitting takes an immediate toll on the body as well as a long-term one.
“You’re at higher risk for pretty much every chronic disease you can name by being sedentary,” Culos-Reed tells Inverse.
Sitting all day long can also compress the discs in the spine, leading to their early degeneration, not to mention chronic back pain that can contribute to negative moods, which can impact physical health.
What seems to be important is limiting sitting time while increasing movement time. “Exercise can take away some of the harm from sitting,” Diaz says, “and sitting can take away some of the benefits from exercise.”
Culos-Reed notes the virtues of taking a flight of stairs or having walking meetings to encourage activity. The bottom line is any form of regular movement punctuating a day of sitting comes with health benefits.
“Right now, the science says movement breaks every 30 minutes are what needs to be done to offset risk,” Diaz says.
Even if you take a moment to flex and point your feet or stand up for a second, that’s a start.
Hack score out of 10 — 👩💻👨💻👩💻👨💻👩💻👨💻👩💻 (7/10 office workers who stand up once every 30 minutes)