These are rapid back-and-forth shuttles with one step in between direction changes. Go two steps to the right, then two to the left.
This really focuses on lateral change of direction, and it's a great way to improve coordination and leg strength/power while building structural integrity in the lower body. Higher reps will scorch your quads and lungs.
Most trainees have the habit of waking up, shoveling down some Fruit Loops, and heading off to the gym before they've truly awakened. In other words, given the amount of prep work they've put into that particular workout, they might as well have left their Fozzie Bear jammies on and stayed in bed.