Hollow body rocks work every part of your core without a single piece of equipment

While there are plenty of different exercises they do to strengthen their abs, there’s one in particular that, according to gymnasts and CrossFit athletes, beats all the others: hollow body rocks.

Hollow body rocks work every single muscle in your core, which makes them one of the most challenging exercises you can do to target the area. Instead of just lying on your back and crunching, you’re firing up your entire body while you’re rocking back and forth, blasting your rectus abdominis, transverse abdominis, and obliques in the process. It also allows you to develop a baseline of strength that will help in many different areas.

“The hollow body rock helps you learn how to stabilize your core in motion so you can perform any and all movements, in and out of the gym,” says Kenny Santucci, CPT, a strength and conditioning coach and the owner of STRONG New York. “It can be used a warm-up exercise to help activate your core, in a workout as a strengthening piece, and as finisher at the end of a workout. Anti-flexion and anti-extension is also a major pillar in becoming more fit and strong, and the hollow body rock trains all the abs and stabilizers of the core to work together.”

While gymnasts and CrossFitters incorporate this exercise into their conditioning sessions on the regular, you can take advantage of its benefits as well by adding it into your core workouts. Follow Santucci’s instructions below and see how many reps you can do before your abs are completely on fire. (Spoiler: It won’t take many.)

How to do hollow body rocks

1. 1.
   Lie on your back. Reach for the ceiling with both arms until your shoulder blades are off the floor. Your arms should be aligned with your ears and fully extended straight out.
2. 2.
   Push your lower back to the floor and, keeping your toes pointed, lift your legs 3 to 6 inches off the floor. Create tension by squeezing your legs arms and abs together.
3. 3.
   Begin to rock back and forth, holding the tension so you don’t break the arch you’ve created with your legs and arms. Keep your abs engaged the entire time.
4. 4.
   Repeat as many times as you can with good form.

When you’re done, try these core-strengthening exercises, too: