INSIDE:
Extreme Marathons
John McConnico / AP
Extreme Arctic Challenge, Ammassalik, Greenland
Participants in this 5-day event, billed as the ultimate test of human endurance, compete in disciplines such as canoeing, cycling, glacier hiking and mountain trekking.
Get the Latest Photos from Time.com
Get TIME photos and pictures of the week delivered directly to your inbox.
Top Stories on Time.com
Photos
INSIDE:
RSS