If you’re looking for a challenge, then consider conquering what the laziest runners out there won’t even touch: extreme winter racing. Here are a few of the most epic, and arduous, winter races in the world.

ALASKA MOUNTAIN WILDERNESS CLASSIC | SOMEWHERE IN THE ALASKAN WILDERNESS
The Alaska Mountain Wilderness Classic traverses roughly 150 miles across our country’s most rugged landscape. Runners typically flank the northern foothills of the Alaska Range past the awe-inspiring peaks of Mount Hayes and Moffit, though there’s not a prescribed route according to race organizers. Glacier crossings, sub-zero lakes and unpredictable weather are just some of the challenges facing competitors looking to win this race. If you’re not the running type, it also makes for a great multi-day backpacking trip.

IDITAROD TRAIL INVITATIONAL | KNIK LAKE, ALASKA
The Iditarod Trail Invitational follows the original route of the Iditarod Trail—and is not for the faint of heart. This ultra marathon combines foot racing, fat biking, and skiing across 350 miles of one of the world’s fiercest climates. If you’re tough enough to survive the frozen tundra once, you’ll qualify for the 1000-mile race. It begins in Knik, Alaska and crosses over the Alaska Range into McGrath.

6633 ARCTIC ULTRA | YUKON TERRITORY, CANADA
Imagine racing 350 miles nonstop across an icy, snowy landscape while pulling a sled full of supplies behind you as you go. That’s what you get when you tackle the 6633 Arctic Ultra. Now entering its ninth year, this arctic endeavor pits winter daredevils against one another from the Canadian village of Inuvik along the Ice Road to Tuktoyaktuk. If you can’t hack the distance, they offer a shorter version that stops after 120 miles.

THE LAST DESERT | ANTARCTICA
In case you think a race with the word “desert” in the title wouldn’t qualify a winter endeavor, the Last Desert actually takes place in Antarctica. It’s the final leg of the infamous 4 Deserts series that tackles the Gobi, Atacama, and Sahara deserts. In order to compete you have to have successfully completed at least two of the previous events. If you qualify you’ll find yourself engaged in a mulit-day race across a polar landscape with minimal equipment. The race route is chosen based on terrain, difficulty, and views, so you’re definitely in for a treat.

BAIKAL ICE MARATHON | SIBERIA, RUSSIA
The Baikal Ice Marathon near Irkutsk, Russia might not be the toughest race on the list, but it certainly is unique. Part of the annual Baikal “Winteriada” festival, the race takes runners across the frozen surface of the world’s deepest freshwater lake. With surfaces ranging from snow to slippery ice as smooth as a hockey rink, running across the terrain is tricky and only for the extremely sure-footed. The landscape is barren and the wind strong, so maintaining your focus and completing the race is highly dependent upon sheer willpower and strength of mind.