Honnold is history’s greatest ever climber in the free solo style, meaning he ascends without a rope or protective equipment of any kind. Above about 50 feet, any fall would likely be lethal, which means that, on epic days of soloing, he might spend 12 or more hours in the Death Zone. On the hardest parts of some climbing routes, his fingers will have no more contact with the rock than most people have with the touchscreens of their phones, while his toes press down on edges as thin as sticks of gum. Just watching a video of Honnold climbing will trigger some degree of vertigo, heart palpitations, or nausea in most people, and that’s if they can watch them at all. Even Honnold has said that his palms sweat when he watches himself on film.
More here – Nautilus
Interested in free climbing? Check out this Free Climbing Guide.