With California’s Yosemite Valley far beneath him, Alex Honnold free solos— which means climbing without ropes or safety gear—up a crack on the 3,000-foot southwest face of El Capitan.

Imagine holding a tennis ball between your chin and neck.” ... Mountain Climber With Hold. How to: Start in a high plank, shoulders over wrists, pelvis tucked, and ribs drawn toward hips.