Learn about a variety of extreme sports, both well-known and obscure, and how and why extreme athletes do what they do.

Are you nuts?! -- In the deep : extreme diving, swimming, surfing, and kayaking -- Hit the road : skareboarding, street luge, BMX, and running -- Hit the slopes : extreme skiing and snowboarding -- Extreme climbing : mountaineering and free-solo rock climbing -- Up in the air : wire walking, skydiving, and base jumping -- More extreme sports survival facts.