About one in four American adults spend at least eight hours per day sitting, according to a new study published in the Journal of the American Medical Association.
Not only that, but nearly half of Americans are physically inactive more generally – getting no moderate or intense exercise during the day.
But would hitting the gym be enough to counteract the negative health effects of sitting? It’s a bit more complicated than that, researchers say.
The study, based on self-reported results, might actually be underestimating just how inactive people are, according to Dr. David Alter, a cardiologist and researcher with the University of Toronto. But he likes how the study authors separated sitting from exercise.
“We kind of know that they are separate and independent from one another. In other words, bad health can arise from sitting regardless of whether we do exercise or not.”
Prolonged, uninterrupted sitting increases your risk of a lot of health problems, he said, such as diabetes, cancer-related deaths, cardiovascular problems like heart disease and heart attacks, and all-cause mortality – which is exactly what it sounds like.
It can also negatively affect your bones and squish blood vessels and nerves in your lower limbs, said Dr. Mark Tremblay, director of healthy active living and obesity research at the CHEO Research Insitute.
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So will an hour at the gym fix all this?
“That’s the huge debate right now,” Tremblay said. “I would argue that the evidence suggests it doesn’t negate it. It mitigates it.”
“If you think of exercise as causing a flow of good through the body and your sedentary time as causing a flow of bad, the good is pushing back against the bad current.”
Alter takes a more positive view of the benefits of exercise. “Sitting and the bad effects of sitting really are in large part, not entirely, but in large part mitigated by exercise,” he said.
A 2016 meta-analysis in the Lancet found that being extremely active and getting about 60-75 minutes of moderate intensity activity per day seemed to counteract the effect of sitting on all-cause mortality. That’s a lot of exercise though – even more than most countries’ general physical activity guidelines. People who did less exercise also saw some benefits.
Although Tremblay believes that exercise is good for you, he also thinks it’s important to address the other side too – not sitting for long periods. And because we spend much more time sitting than exercising, it’s actually easier to work on.
“Get your daily dose of physical activity for sure. If you can break up extended sitting, there’s additional health benefits that are likely to be there for you as well.”
You simply need to interrupt your periods of sitting, he said.
“It doesn’t mean in your office doing jumping jacks every half hour. Just, literally, interrupt the sitting. Go to the bathroom. Go to the bathroom that isn’t closest to your office. Just interrupt the immobility.”
He makes phone calls – including the interview for this article – while standing or walking around. He also suggests people get up more often for a glass of water at the office, or answer the occasional email from a colleague in person, by walking over to their desk.
People are meant to have variation in their day, he said, so sitting, standing, exercising, sleeping and eating too much are all bad for us – moderation is better. Moving around, doing light physical activity, even if it’s not intense exercise, is beneficial.
Both exercising more and sitting less matter, he said, and we should work on both.
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