These races have you swimming in fjords and climbing European summits in an effort to conquer the biggest challenge you'll face—the desire to quit.
Aurlandsfjellet Xtreme TriathlonNorway 1 of 9
The race starts with a 1,900-meter swim along a fjord, leads into the 98-kilometer bike course with more than 3,050 meters of climbing, and finishes on a mountain 900 meters above sea level. The reward for your hard work: lush, mountainous, Nordic scenery.
Isklar Norseman Xtreme TriathlonNorway 2 of 9
The day starts at 4 a.m. when athletes board a ferry that takes them 3.8 kilometers into a fjord for the swim start. Waiting for them on land is 180 kilometers of cycling over five mountain passes and a marathon that finishes on the rocky summit of a mountain.
SavageMan TriathlonMaryland 3 of 9
If you can make it over the Westernport Wall on the bike, which has a 31 percent grade, a mighty mountain awaits you on the run. The run takes you across the Eastern Continental Divide at Big Savage Mountain and the 7.1-mile ascent includes 1,950 feet of elevation gain. It's such a tough stretch that a race within the race was born to see who could break the ascent record of 31 minutes, 30 seconds.
IRONMAN World ChampionshipHawaii 4 of 9
Not only is this one of the toughest triathlons, it's one of the hardest in which to to earn a spot. For athletes lucky enough to toe the line, the mass swim start is a telling precursor for a treacherous day but the intensity only picks up on the bike and run courses where athletes face harsh wind, heat and humidity. By the time you hit the Energy Lab, about halfway into the run, it threatens to zap any energy you have left. For many, it's pure will that gets them through the lab, where road temps can hit 115 degrees, to the home stretch. But waiting there is a spectator reception that's unmatched at any other race.
The 9 Bar Helvellyn TriathlonEngland 5 of 9
Image by Jason Newsome
The swim is pretty straightforward and the bike, as expected, includes some steep mountain passes, but it's the third leg that really gets you in this event. As the TriHard website points out in all caps and bold text, "This is far from an ordinary triathlon run route." Nine miles of the the "run" goes straight up England's third highest peak and two people died on the course in 2008.
IRONMAN LanzaroteSpain 6 of 9
While IRONMAN races are considered the toughest triathlons in the world, this is one of the toughest IRONMAN events. The reason for its reputation: the bike. Athletes face more than 2,551 meters of climbing and strong winds. The run, although flat, has athletes contending with fierce heat.
Brutal Extreme TriathlonsNorth Wales 7 of 9
If you're not up for a tough triathlon, don't sign up for this one; it's brutal! Athletes can choose between the half, full or double Brutal and the further you go, the harder it gets.
24 Hours of TriathlonWisconsin 8 of 9
In this race you swim, bike, and run just as in any old tri, but then you do that again, and again, and again. The goal is to log the most swim-bike-run combinations as you can over the course of 24 hours. You can enter as a team but the real test of endurance is reserved for the solo racers.