It makes you fat.
It makes you weak.
It makes you more likely to keel over dead.
How do we know?
Because "inactivity researchers" have finally cracked the code.
Specifically, they have figured out why some people get fat when they eat too much and other people don't get fat, even when they eat the same amount:
The people who get fat get fat because they sit around all day. The people who don't get fat don't sit around as much.
Importantly, the difference between the fatties and the non-fatties in the study had nothing to do with exercise. None of the folks in the "inactivity" study were allowed to exercise. The folks who didn't get fat didn't exercise--they just didn't spend as much time sitting. Instead, they stood. They walked. They took stairs instead of elevators. They fidgeted. Etc.
And sitting doesn't just make you fat. It makes you sick, too.
Why is sitting so bad for you? Per James Vlahos in the New York Times, here's what happens when you sit:
Electrical activity in the muscles drops — “the muscles go as silent as those of a dead horse,” [inactivity researcher Marc] Hamilton says — leading to a cascade of harmful metabolic effects. Your calorie-burning rate immediately plunges to about one per minute, a third of what it would be if you got up and walked. Insulin effectiveness drops within a single day, and the risk of developing Type 2 diabetes rises. So does the risk of being obese. The enzymes responsible for breaking down lipidsand triglycerides — for “vacuuming up fat out of the bloodstream,” as Hamilton puts it — plunge, which in turn causes the levels of good (HDL) cholesterol to fall.
Hamilton’s most recent work has examined how rapidly inactivity can cause harm. In studies of rats who were forced to be inactive, for example, he discovered that the leg muscles responsible for standing almost immediately lost more than 75 percent of their ability to remove harmful lipo-proteins from the blood. To show that the ill effects of sitting could have a rapid onset in humans too, Hamilton recruited 14 young, fit and thin volunteers and recorded a 40 percent reduction in insulin’s ability to uptake glucose in the subjects — after 24 hours of being sedentary.
Over a lifetime, sitting really can kill you:
- Men who sit 6 hours a day are 20% more likely to die that men who sit 3 hours a day
- Women who sit 6 hours a day are 40% more likely to die