For much of history, human beings had an active lifestyle, but it did not include any kind of formal exercise.

Movement just for movement's sake is a relatively new phenomenon in human history.

Until recently, only the wealthy people had a chair with a seatback. Human beings used to either sat on the ground or on stools or benches.

A seatback makes sitting more passive than just sitting on a bench or stool because you use fewer muscles to stabilize your upper bod...

Getting up every 10 minutes or so just to go to the bathroom or make yourself a cup of tea is turning on your muscles. It uses up fats and sugars in your bloodstream, and it produces molecules that turn down inflammation.

Interrupted sitting and not sitting in a chair that's nestling you...

There is this idea that running wears away your cartilage and causes arthritis in the knees. But it is not valid. Studies show that people who run more are less likely to get arthritis in their knees and more likely to benefit from physical activity.

Knee injury is indeed most com...

As we age, physical activity becomes more important. One serious negative consequence of older individuals who are less physically active is that their muscles dwindle, they atrophy. The less they are active, the frailer they become.

The good news is that you can turn it around. The mechan...