double unders x 20 (50 singles)
Workout: 200 tuck jumps
Breakdown: Think about being springy like a pogo stick, bounding off the ball of the foot, then tucking your knees up at the top of the movement.
Standards: Feet leave the ground at the same time, when in the air, both knees must rise above the hips.
Scale: do 100 or 50 reps.
Make it more challenging: Have a friend keep count and use their extended arm as a height target above your sternum forcing you to touch his hand with your knees with each tuck jump to count.