By BJ Gaddour
This iso squat ladder challenge pits you against gravity.
By adding an extended pause during the toughest part of the squat—the bottom—you intensify the exercise without adding weights. The isometric hold reduces the amount of “bounce” or elastic energy stored in your muscle fibers, which means you must work harder to push your body out of the hole.You also increase the time your muscles are under tension. The result: bigger, stronger glutes and quads.

Here’s how it works: Hold the bottom of a bodyweight squat for 30 seconds, and then stand up and perform one full squat. Then do a 30-second hold again, but follow it up with two bodyweight squats this time.

After each iso hold, continue to add one full squat to your rep count. Do this until you must take a break or stop altogether.

Your final score is your highest rep count. Try to beat that number the next time you perform the challenge.