Who uses it: Tommy Zbikowski, All-American safety from University of Notre Dame
Who coaches it: Kevin Kasper, Zbikowskis trainer and six-year NFL veteran who currently plays for the Cleveland Browns
Kasper says: This is one of our primary exercises to recruit muscle B-twitch fibers, [which are necessary] for explosiveness and cutting to the ball.

• Step forward into lunge position with left leg
• Hold for a few seconds
• On partners cue, jump and switch position of front and back legs
• Repeat for specified reps

Sets / Reps / Rest: 3 / 10 / 30-60 seconds
Kaspers cues: Keep your body upright // Switch legs as fast and quickly as possible // Keep arms bent 90 degrees // Stay on balls of feet
Zbikowski on the shoe: "[When you're] on the balls of your feet, you feel a good amount of cushion. Overall lightness of the shoe is what helped me out when [I'm] trying to switch; it gives you a pretty good base."