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 is the founder of Unofficial Networks and a passionate skier with over two decades of experience in the ski industry. In 2006, he launched the blog from Lake Tahoe with his brother John, evolving...