Romney, Ryan 'state of health' letters to be released

(CNN) -- Letters evaluating the physical health of Mitt Romney and Paul Ryan will be released Friday afternoon, Romney's campaign said.

The evaluations will be published on the campaign's website at the same time as Romney's 2011 tax return. The letters, the campaign wrote, will make "public their current state of health."

Ryan, 42, is well known for his fitness routing using P90X, and has led sessions of the cross-training regime in the House gym.

"My dad died of a heart attack at 55, my grandfather at 57, so I've always had this incentive to stay healthy," Ryan told CNN's Gloria Borger last year.

Romney, 65, is often seen partaking in water sports at his lakefront home in New Hampshire. He is known to use elliptical machines for regular workouts, but told CBS in August he would consider trying Ryan's exercise of choice.

"I've never tried that," he said. "I might have him show me how to do it someday. I get on the elliptical or the treadmill or the stationary bike for about 40 minutes and that's about it for me. But that workout of his, he's in pretty good shape."