Ever since studies found that those who spend all day sitting tend to have a higher death rate than those who move around, researchers have been trying to answer the question: how much moving does it take to make up for too much sitting?
The answer, according to a very large study published recently in The Lancet is: less than you might think.
Researchers conducted a meta-analysis of 16 large studies that included more than 1 million people. Crunching the data a number of different ways, they came to the conclusion that 60 to 75 minutes of moderate physical activity was enough to eliminate the risk of death related to sitting, even for those who sit more than eight hours per day.
What kind of moderate activity? You don't have to take up gymnastics or triathalons. Things like walking to work, walking the dog, riding a stationary bike, line dancing, golf or softball, doubles tennis, or coaching sports will do it.
For those who just can't spare an hour, even 25 minutes of moderate activity was found to be somewhat protective.
TV watching is worse than working
The way energy expenditure was measured, vigorous activities count more, so less time of the most strenuous exercise is needed to be protective, said Monique Tello, MD, MPH, writing in the Harvard Health Blog.
That's the good news.
The bad news, says Tello, is that the encouraging findings apply to those who sit at a desk or behind the wheel all day. They don't apply to plopping down on the couch and watching TV for hours on end.
The researchers found that TV time is associated with an even greater risk of death, and exercise is not as protective; even a full hour of activity can't make up for five hours of TV watching.
Why is TV watching so much more harmful? Researchers aren't certain, Tello said, but it may be because even though we may sit at a desk or at the wheel of a truck or bus all day, we still tend to jump up to go to meetings, check a file, or unload a shipment.
But TV watching? It's a total blob-out for most people. Also, Tello notes that most TV watching takes place in the evening, usually after dinner, which could increase the effect on blood sugars and fat metabolism. There's also the little matter of snacking.
The takeaway message, says Tello, is that every little bit of movement helps keep arteries flexible and blood sugar under control. If all else fails, you might want to consider dragging the exercycle into the family room.