These days, it seems every outdoor sport, from hiking to mountain biking, is branded "extreme." Have you hiked without energy bars? You're extreme! Did you mountain bike through a muddy puddle? That's extremely extreme!
Enough already, right?
We've tracked down 13 hair-raising, gut-wrenching, panic-inducing outdoor pursuits that merit the "E" word. So strap on your crash helmet and check these out truly extreme sports.
This form of whitewater kayaking is so intense, it often requires kayakers to plunge off tall waterfalls. The sport grew in prominence in the early 1980s with the development of increasingly durable kayaks. Besides the obvious danger of getting slammed into jagged rocks, there is a chance that creekers can be sucked underwater. In extreme cases involving powerful currents, some kayakers have drowned.
BASE stands for Buildings, Antennas, Spans (bridges), and Earth (cliffs). BASE jumping aficionados fling themselves off these various structures and deploy parachutes that (hopefully) carry them to a safe landing. The sport dates back a century or more, but experts trace its modern incarnation to 1978, when four men filmed their jump off El Capitan in Yosemite, Calif.
How dangerous is it? One study of the sport over 10 years calculated one death for every 2,317 jumps, making BASE jumping the most dangerous recreational sport in the world. It's significantly more dangerous than skydiving because participants have less time to act if a parachute fails, and more likelihood of hitting a fixed object. But hey, it delivers one serious rush.
You've seen video of surfers dropping into waves the size of skyscrapers. The biggest waves move so fast that surfers have a hard time paddling into them. Enter the Jet Ski, which can tow a surfer into even the most beastly, fast-moving waves.
The sport emerged in the mid-1990s when established big-wave surfers like Laird Hamilton and Dave Kalama began experimenting off Hawaii. Hazards include being crushed against jagged reefs and being held underwater for a prolonged period after a wipeout. A number of professional surfers have met their demise in such conditions.
Practiced by less than one percent of rock climbers, free soloing is, as its name suggests, climbing without the aid of safety ropes, harnesses or other equipment that many climbers consider essential. It's not for the faint of heart. Besides the ability to support your entire body weight on just two or three fingertips, free soloists must possess an intense level of focus. One tiny slip can mean certain death. Not surprisingly, several of the sport’s giants have died in free-soloing accidents.
Freeride Mountain Biking
Freeride mountain biking emphasizes whacked-out and sometimes death-defying stunts. Like traditional mountain biking, freeride is done in wilderness settings, but courses can include man-made additions to aid in stunts and tricks.
Started as a niche sport among biking enthusiasts, mountain biking gained popularity in the late 1970s and '80s when road bicycle companies started making beefed-up bikes. Freeride emerged later and has been growing steadily ever since.
Wingsuit flying is a particularly gonzo offshoot of BASE jumping and skydiving. Pilots take a big leap, then soar with the help of "wings." How effectively? Wingsuits have a glide ratio of 2.5, meaning for every one meter of descent they can glide 2.5 meters forward.
The first known attempt at a wingsuit flight was made by an Austrian man who died after jumping off the Eiffel Tower in 1912. The modern wingsuit was developed in the late 1990s; the first commercial version became available in 1999. Needless to say, wingsuit flying is extremely dangerous and requires a tremendous amount of skill. Two hundred skydives is considered the minimum prerequisite before learning to fly a wingsuit.
As its name suggests, ice climbing is the scaling of vertical ice formations — ice falls, frozen waterfalls, cliffs covered in ice. The sport emerged as its own discipline in 1908 when a British climber invented the crampon — the toothed claw that's fastened to climbing boots. Before crampons, climbers scaled ice by a method called "step cutting," which involved chipping out each foothold with an ice pick or ax. Advancements throughout the 20th century accelerated the sport's growth. Dangers include the threat of avalanches and the persistent exposure to icy temperatures, which can compromise movements by numbing hands and feet.
The idea of kitesurfing dates back to the late 1970s, but the sport really only started gaining popularity in the mid-90s, when big-wave surfer Laird Hamilton and French kitesurfing pioneer Manu Bertin began wowing windsurfers off Maui with their newfangled kite contraptions.
Since then, the sport, which is also known as kite boarding, has taken off, with an estimated 250,000 enthusiasts today. Like a lot of extreme sports, kitesurfing has a steep learning curve and is extremely dangerous. Hazards include being flung through the air into hard, stationary objects by an out-of-control kite. (Ouch.)
Also known as volcano boarding or ash boarding, volcano surfing is essentially surfing down the side of a volcano. Riders hike up on their own (chairlift operators have yet to set up shop in these parts) and then slide down on plywood boards reinforced with metal and Formica.
The sport is only a few years old. Its birthplace is Cerro Negro (pictured), an active volcano in western Nicaragua. Beginners ride down while sitting on their boards, while veteranos stand like snowboarders. Protective gear and goggles are required — volcano rocks can be surprisingly sharp.
Cave diving is, as its name suggests, scuba diving in underwater caves. Superstar diver Jacques Cousteau is considered the father of the sport.
Not surprisingly, caves pose a number of dangers. In the event of an equipment failure, caves often prevent a quick ascent to the surface. They can also contain swift, unpredictable currents, and visibility can become severely compromised should a diver stir up sediment. Cave-diving deaths are a yearly occurrence: Even experienced divers fall victim to the caves' dangers.
Similar in concept to kitesurfing, kite skiing utilizes a traction kite and harness to propel a skier across snow and sometimes into the air. While the history of kite skiing is hard to pin down, it's thought to have begun in the United States in the 1980s, when skiers experimented with parachutes. The sport caught on in Europe, and particularly in Scandinavian countries. Frozen lakes and wide open snow fields provide the ideal environment, but more daring practitioners are taking kites into downhill backcountry, sometimes literally flying down mountainsides.
Highlining is similar to tightrope walking in that it involves traversing a nylon line across an elevated position. But in highlining, the line isn't stabilized or taut. What's more, walkers don’t use a balancing pole.
The sport's origins can be traced to slacklining, which was invented in the 1970s and incorporates tricks performed on a line located close to the ground. While many highliners use a tether in case of a fall, some don’t. Um, we'd opt for the tether.
Next: 15 Gut-Wrenching Wipeout Photos
While most extreme sports involve death-defying speeds or outlandish heights, ultra marathons present a different kind of challenge: a battle of endurance — both physical and mental — that can last hours, days or, in some cases, even weeks.
A short ultra marathon is considered 31 miles —roughly five miles longer than a standard marathon. But distances can range up to 100 miles and beyond. Races are run on roads, trails or both. The Silverton 1000 is a yearly challenge in Colorado in which participants are given 18 days to run 1,000 miles on a designated trail. That’s an average of nearly 55.6 miles per day. Despite its difficulty, ultra-marathon running is growing in popularity, with tens of thousands of devotees around the world and hundreds of races conducted each year in the U.S. alone.
The World's Most Extreme SportsCheck out these 13 hair-raising, panic-inducing pursuits