A sedentary lifestyle is defined by an excessive amount of daily sitting. Be it to watch television, work the computer, or even read, its negative health influences include increased anxiety, cardiovascular disease, diabetes, depression and more. But if a person exercises, everything gets reversed — right? Not so, claims new research. As reported by Men’s Health Magazine in 2010, a desk job may literally be the end of us, no matter how many spin classes we take.
Marc Hamilton is a physiologist and professor at the Pennington Biomedical Research Center in Baton Rouge, Louisiana. As he told Men’s Health, a man who sits 60 hours at a desk job but still works out for 45 minutes a day five times a week still has a sedentary lifestyle. According to Hamilton, "People tend to view physical activity on a single continuum. On the far side, you have a person who exercises a lot; on the other, a person who doesn't exercise at all. However, they're not necessarily polar opposites." Hamilton and his growing body of evidence shows that even “a sculpted six pack” won’t diminish the harm caused by your office chair.
How is this possible? The difference seems to be between exercise activity and non-exercise activity. This is the difference between running, biking, or doing weights as opposed to walking, mowing the lawn, or emptying your dishwasher. A 2007 report found that people with the highest levels of non-exercise activity burn significantly more calories than those who work out regularly. Experts say the difference simply can be about standing. People who stand on the job burn more calories than those who don’t — not matter how much the sedentary worker actually works out.
Dr. Peter Katzmarzyk is a researcher at one the nation's leading obesity research centers. He says that sitting, not weight or exercise, is a key factor in determining a person’s overall health. According to Katzmarzky, "The evidence that sitting is associated with heart disease is very strong. We see it in people who smoke and people who don't. We see it in people who are regular exercisers and those who aren't. Sitting is an independent risk factor."
This may have something to do with an enzyme called lipoprotein lipase (LPL). This enzyme determines if a person will store fat or burn energy. In mice forced to lie down, LPL activity decreased. But in mice that stood around all day, LPL levels were 10 times as active.
Sitting for long periods of time may contribute to heart damage, according to an October 2017 study. A team of cardiologists pulled data from more than 1,700 participants in the Dallas Heart Study, ongoing research looking at the cardiac health of an ethnically diverse group of men and women. They found that sitting for most of the day is linked to a buildup of troponins, proteins released by heart muscle cells when they are damaged or dying, explains the San Francisco Chronicle.
In the study, which was published in the journal Circulation, researchers found that sitting was more closely associated with unhealthy levels of troponins than exercise was linked to healthy levels of the proteins.
Similarly, a 2016 study in Circulation seems to back up these claims about exercise and a sedentary, desk-bound lifestyle.
"The evidence to date is suggestive, but not conclusive, that sedentary behavior contributes to cardiovascular disease and diabetes risk," a team led by Deborah Rohm Young, of Kaiser Permanente, Southern California explained in their study. "Given the current state of the science on sedentary behavior and in the absence of sufficient data to recommend quantitative guidelines, it is appropriate to promote the advisory, 'Sit less, move more'."
But even moving more may not help in the long run. If you're spending too much time reading, watching TV, sitting at a desk or reclining, Young says the exercise may not be enough.
"Regardless of how much physical activity someone gets, prolonged sedentary time could negatively impact the health of your heart and blood vessels," she explained in a statement.
This doesn't mean you should just give up and lounge around, of course. Physical exercise can still help your body in a number of ways, and Young has stressed that her team's study isn't demonstrating a direct connection between being sedentary and health issues.
Editor's note: This story was originally written in October 2010 and has been updated with new information.