New Delhi, June 27 -- Sitting takes a toll on our health. You can reverse the effects with exercise-a lot of it.

If you sit eight hours a day, it takes 13,000 steps a day to completely offset the effects, Dr. William Kraus, a cardiologist at Duke University, told Barron's.

"We have to pay a price for sitting eight hours a week," he said. "It isn't a gimme."

Kraus, who advised the federal government's Centers for Disease Control and Prevention on its fitness guidelines, follows his own advice. Every day, he runs or walks 13,000 steps.

In fact, he talked to Barron's while he was walking about.

That big number really is how much it takes to "overcome sitting eight hours a day, which most of us do, if we're being honest," Kraus says.

Wh...