HOW: Stand on one side of the ladder at the end facing it with one foot in and the other out in a staggered position. While moving laterally through each block, alternate a scissor-like movement with your legs in and out of each block. Alternate your arms as well to help with speed.
FEEL: You should feel the muscles in your legs working.
COMPENSATION: Stay on the balls of your feet and in control of your feet and body. Keep your chest upright and stay facing one way.