When I think of healthy, fit, and strong celebrities, Hayden Panettiere is one famous lady who comes to mind. How does she stay in shape? The Heroes actress lifts weights twice a week and runs 30 minutes or longer at least three days a week. But she doesn't do it to look and feel good. She does stay fit in order to stay strong and build endurance for diving.

Yep, Hayden loves to free dive in the ocean (without scuba gear) and she told Self, Free diving sounds like a blast! Read what Hayden has to say about the state of cellulite and her body when you read moreStaying fit allows Hayden to be strong enough to swim with dolphins because she says, "You have to swim fast to keep up!" Not only does Hayden love to swim with the ocean's creatures, but she also swims for them. She's a spokeswoman for The Whaleman Foundation, an organization dedicated to protecting marine life, which she feels very strongly about. Even though you probably know Hayden as Claire, the invincible cheerleader on Heroes, you can also see her in another fearless role in the documentary The Cove, where she joins a protest to prevent the capture and slaughter of whales and dolphins.