Legendary ultrarunner Kilian Jornet has released some intense footage of a run he made along a ridge in Chamonix, France. The run was on a knife ridge only a foot wide, with hundreds of feet of exposure on either side.

Tim Konrad, founder of Unofficial Networks, is a skier with over 20 years in the ski industry. Starting the blog in 2006 from Lake Tahoe with his brother John, the website has grown into one of the world’s...