The human body is built for movement. The ancient Greeks and Romans recognized the importance of physical activity for proper health, and modern medicine has confirmed the links between regular exercise and disease prevention.
But it wasn’t until relatively recently that sitting and other sedentary behaviors emerged as threats to public health.
So-called “sitting diseases,” which are health issues linked to sitting and inactivity, are now a major area of research. And there’s ample evidence that spending too much of your time motionless — even if you exercise regularly — raises your risks for cardiovascular disease, type 2 diabetes, and premature death, according to an editorial published in 2022 in BMJ. There is also evidence that it raises your risk for mental health conditions such as depression, according to a cohort study published in January 2023 in the Journal of Affective Disorders.
“Our evolution and genetic makeup dictate that humans are made to move,” says Emmanuel Stamatakis, PhD, professor of physical activity, lifestyle, and population health at the University of Sydney in Australia. “While sitting motionless, our bodies and minds degenerate and age quickly, leading to chronic disease and premature death.”
Dr. Stamatakis has pushed for public health authorities to issue formal warnings and guidelines about the risks of too much sedentary time. Many other researchers in the field have done the same, according to a review published in 2019 in the British Journal of Sports Medicine.
Also worrisome: Stamatakis says some of the more recent findings suggest that while sitting is bad, standing in one place (for example, at a stand-up desk) and other forms of inactivity may not be all that much healthier.
“Movement is the key,” he says. “Standing can be a part of a healthy activity pattern but, on its own, it is unlikely to lead to substantial benefits and cannot improve fitness.”
The Claims About Too Much Sitting
The theory here is straightforward. Your body is built for movement, and spending too much time not moving can cause a wide range of negative health effects. That seems to be true even if you’re exercising regularly.
“The bad effects of inactivity seem to be separate from the good effects of exercise,” says Edward Coyle, PhD, a professor and director of the Human Performance Laboratory at the University of Texas at Austin. “Even if you meet the current guidelines for exercise, if you otherwise sit all day long, you still seem to be at increased risk for heart disease and death.” Current guidelines recommend that adults get at least 150 to 300 minutes a week of moderate-intensity aerobic physical activity, according to the Office of Disease Prevention and Health Promotion.
Dr. Coyle says exercise is still absolutely necessary and healthy. But just as exercise won’t protect you from the harms of smoking, it also can’t wholly offset the risks of spending all your nonexercise time sitting or in other sedentary behaviors.
“‘Sitting is the new smoking’ was a popular saying for a while,” he points out. “I think there’s some validity to that,” he adds, adding that smoking is almost certainly more dangerous than sitting.
What the Science Says About Too Much Sitting and Health
There is a “dose-dependent” relationship between sitting time and risk for cardiovascular disease, cancer, and mortality, according to a research review published in 2019 in The Journal of Nutrition, Health, and Aging. In other words, the more time a person spends sitting, the more their risks for these sitting diseases go up.
Regardless of physical activity levels, too much sitting is associated with an increased risk for heart disease, according to past research.
And studies have shown that sedentary behaviors are associated with an increased risk for symptoms of anxiety and depression, according to a cross-sectional study published in April 2020 in Preventive Medicine.
Why are sitting and other sedentary behaviors so risky? “We don’t know the exact mechanism at a physiological or molecular level, but it seems that something is generated with prolonged inactivity and sitting that affects a number of the body’s systems,” says Coyle.
For a study published in 2022 in the journal Exercise and Sport Science Reviews, Coyle and his coauthors found that a one-hour bout of sitting interfered with the kind of fat breakdown that normally occurs following exercise.
He says a lot of his work has focused on the relationship between sitting and fat metabolism. “Fat metabolism is rapidly responsive to both inactivity and exercise, so we’re using it sort of like the canary in the mine,” he says. “If you’re inactive, you have impaired fat oxidation and also reduced clearing of triglycerides from the blood after eating.”
The exact relationship between sedentary behaviors and mental health problems such as anxiety and depression also remains unclear. But there is a strong relationship between mental and physical health, according to a study published in 2019 in Perspectives in Psychiatric Care. If sitting is bad for the body, it makes sense that it could also negatively affect a person’s mind.
How Can You Make Sure You’re Not Sitting Too Much?
Coyle says the total amount of time you spend sitting seems to matter less than how often you break up long bouts of chair time with periods of activity.
In one of his studies, published in 2020 in Medicine and Science in Sports and Exercise, he and his coauthors had people sit for eight hours at a stretch. However, some of the people got up five times each hour to engage in very short bouts of vigorous exercise — specifically, a four-second sprint on a stationary exercise bike.
While the total amount of exercise for the entire eight-hour period was just 160 seconds, the people who got up for the four-second breaks burned significantly more fat and cleared triglycerides more effectively the next day, his study found.
“Short, frequent breaks from sitting seem to be very helpful,” he says.
Unfortunately, standing up doesn’t seem to be much better than sitting if you’re not moving around.
Another of Coyle’s studies, a paper published in 2021 in PLoS One found little difference between people who stood for six hours and those who sat for six hours. However, that same study found that getting up and going for a two-minute walk every 30 minutes seemed to offset the risks of sitting.
Stamatakis echoes many of these recommendations. “Break up prolonged sitting every 20 or 30 minutes,” he advises.
Some of his work, published in Nature Medicine in December 2022, used wearable activity trackers to show that even short (one to two minute) bouts of activity, such as climbing stairs or walking quickly, seemed to offset many of the health risks associated with long bouts of sedentary time.
Finally, both Coyle and Stamatakis say that exercise is still important.
“The healthiest thing to do is to be active throughout the day, and then also exercise on top of that,” Coyle says. “So it’s avoiding sedentary behavior to prevent the bad from happening, and also exercising to gain the good.”
The Bottom Line
Modern life makes it pretty easy to spend most of the day sitting down. But the latest research, not to mention common sense, suggests that our bodies weren’t designed for so much inactivity.
While it took some time for medical scientists to catch up to our changing patterns of behavior, it seems clear that sitting and other sedentary pursuits are a risk to our health. Fortunately, the antidote to this seems fairly simple and painless: Break up long stretches of sitting with frequent movement breaks.
Source: everydayhealt
