Pushing the Extreme
Skiing not your thing? Find rock-climbing boring? Athletes have shown their grit and made others question their sanity in dozens of ways.

Felix Baumgartner
Jorg Mitter/Red Bull Content Pool
Skydiving may be a rush, but it ends quickly unless you’re Felix Baumgartner, who in October 2012 rode a balloon 24 miles into the air and leaped out, landing less than 10 minutes later. On the way down, he not only broke the record for the fastest and highest free fall, he became the first human to break the sound barrier.

Garrett McNamara
Pro surfer Garrett McNamara did the only thing he could after breaking the world record for the largest wave ever surfed: He broke it again this past January, dropping into a bone-crusher off of the coast of Portugal that was estimated to have been as tall as 100 feet.

Nik Wallenda
How do you follow up crossing 1,800 feet of Niagara Falls while standing on a 2-inch-thick wire? After completing that feat in 2012, Nik Wallenda strolled across a major Florida highway in January, traveling 600 feet on a thin wire suspended almost 200 feet above the road.

Eric Larsen
Save the Poles/MCT/Newscom
Eric Larsen can’t seem to get enough of the cold. In 2010, he became the first person to travel to the North Pole (a 41-day journey), to the South Pole (a 750-mile ski traverse) and to the summit of Mount Everest in a 365-day period.

Steve Knowlton
Zuma Press, Inc./Alamy
Think running an ultramarathon is tough? Try running across the entire United States. In 2010, Steve Knowlton traveled from Seattle to Key Largo, Fla., by himself, putting one foot in front of the other for 3,717 miles.

Phil Harwood
Images of Africa Photobank/Alamy
The Congo River is the deepest and perhaps most dangerous in the world. Phil Harwood canoed all 3,000 miles of it, braving vicious animals and political unrest. An attempt by three professional kayakers to do a similar trip ended when one was eaten by a crocodile.

Martin Strel
Matt Carr/Getty Images
Martin Strel has swam many of the rivers of the world, but perhaps his most impressive feat was in 2007 when he swam 3,274 miles of the Amazon, spending 10 hours a day in the water for 66 consecutive days.

Charlie Head
Courtesy Charlie Head
Charlie Head traveled on a stand-up paddleboard for 500 miles around the southern coast of England in 2012, but that feat was mere practice for his autumn journey across the entire Atlantic Ocean on a board about the size of a dining-room table.