Oprah's '20 Years Younger Challenge' (VIDEO)

Oprah Winfrey and Bob Greene asked a number of 'Oprah Winfrey Show' (weekdays, syndicated) fans to take the "20 Years Younger Challenge," based on Greene's book of the same name. They followed Greene's regimen for two months, and on Wednesday's episode, Winfrey featured the women, showing the group's "before" picture and then following their progress.

In a pre-recorded clip, Winfrey showed the women working out and talking about their experience. "I have to admit I wouldn't imagine myself at almost 50 wearing a tank top and stretchy pants in front of the camera," said one woman working on an elliptical machine.

There's no way to quantify whether they actually seem 20 years younger, but some of them reported benefits like kicking blood pressure pills. Maybe they mostly feel 20 years younger.