In the 1970s, there was no one cooler than the Fonz. But when you find out how actor and best-selling author Henry Winkler is changing children’s lives, you’ll realize you had no idea just how cool he really is.

Just a few years ago, Roderick Sewell was a homeless teenager with no legs who was failing school. Today, he’s a world-class athlete, attends college and he’s set his sights on a big goal — making the Paralympics team. (click here to watch the video version of this story)

Her name is Ruth Flowers, but her legions of fans know her better as Mamy Rock. She’s known all over the world for her work both behind the turntables and in front of hard-rocking crowds. Even in her 70s, she still just wants to dance! (click here to watch the video version of this story)

She didn’t even start exercising until she was nearly 65 years old. Now 71, Jean Evansmore has completed more than 100 marathons and holds a record for doing seven in seven days. She explains what motivated her to get active.

Dr. Daniel Thomas represents a new breed of physicians willing to think outside of the box. He wants to keep you healthy, young and vibrant, and he has a plan to do just that.

Joel Sartore is a word-renowned photographer for National Geographic who believes all species of animals deserve a place on the earth. He describes his one-man mission to shoot portraits of nearly 6,000 animals, before it’s too late.