BOSU Medicine Ball Crunches

This exercise provided courtesy of Devin Wicks, Director of Fitness Operations at the University of California, Berkeley and specialty strength coach for some of the university's elite sports teams.

Crunches on a BOSU ball are a core buster. Balancing on the ball is itself a very difficult exercise. Add crunches for a major ab workout. Balance a medicine ball on your legs for a lower ab experience akin to death.

Muscles Worked
Abdominals (Center and Lower)

Starting Position
Lie on your back on a BOSU ball. The BOSU will be under your back, so that you can balance entirely on the ball. Bend your knees at a 90-degree angle, such that your calves are parallel to the floor. Place your hands behind your head with elbows wide.


  1. From the starting position, put your hands behind your head and do a crunch, using your center to lift your shoulders slightly off the ball.
  2. From the top of your lift, lower your shoulders back down. Your calves should stay parallel to the floor throughout this exercise, and your body should balance on the ball.
  3. Maintaining your balance, continue to do crunches with your legs remaining elevated and bent at 90 degrees throughout.
To add difficulty to this exercise, place a medicine ball on your shins as you do the crunches. Your calves should remain parallel to the floor as you lift your upper body.

About Devin Wicks: Devin Wicks (ACSM-HFI, USAW Club Coach) is the Director of Fitness Operations for UC Berkeley where he develops health and fitness programs for the campus community. He also works as a conditioning specialist for Cal Athletics where he has developed targeted training programs for several Olympic Gold Medal athletes. Devin has presented and toured nationally, providing cutting-edge education for fitness industry professionals and enthusiasts alike.