Count the number of hours you sit each day. Be honest.
"If you commute an hour in the morning and hour after work — that's two hours, and if you sit at an eight-hour-a-day desk job that's 10," says epidemiologist Loretta DiPietro of the Milken Institute School of Public Health at George Washington University.
"Then you come home at, say, 6 p.m., eat dinner and crash into your recliner for another three to four hours," says DiPietro. "That's 13 to 14 hours of sitting."
Being immobile like that for many hours each day does more than raise the risk of a host of diseases. DiPietro and her colleagues have good evidence that, as the years wear on, it actually reduces the ability of older people to get around on foot at all.