This Plank Variation Is The Most Challenging Yet

Planks have a gold-star reputation for being an amazing abs exercise. Once you get the hang of the traditional move, and want a little something more, there are plenty of ways to up your plank game—one move we love is the forearm plank rock.

The forearm plank rock takes the basic plank, which is a static hold, and adds in a little movement by shifting your body slightly forward and backward. This rocking sensation fires up your muscles even more as you need to exert more energy to complete the movement, explains Alexis Novak, an LA-based trainer and yoga instructor.

And the benefits don't stop at your abs. It's particularly great for working your shoulder muscles, because they need to work to move your body back and forth, Novak explains. "It also targets the accessory [or smaller] muscles that sometimes take a back seat when you do other shoulder-focused exercises, like a shoulder press," she says.

Novak actually deals with sensitive shoulders, but she likes this move for building up strength in those muscles because it doesn't require added resistance or a large range of motion. She modifies the move by flipping her palms (so that they are facing the ceiling) while in the forearm plank position. "By flipping the palms we change the orientation of the arm bones in the socket, and are creating space for the bone, joints, and surrounding fascia to glide more effortlessly," she explains. However, if you have shoulder problems, make sure you talk to your doctor to make sure you're cleared to do this exercise.

Ready to rock? See how to do the forearm plank rock below.

Forearm Plank Rocks

• Start in a forearm plank with your elbows stacked under your shoulders and your forearms resting on the ground. (You can also try this move in high plank.)
• Rock your entire body forward, coming more onto your toes, and allowing your shoulders to go past your elbows.
• Rock back to your starting position.
• A couple of form tips: Make sure you keep your core engaged throughout the entire move. Don’t allow your hips to raise or drop, and keep pushing your forearms against the floor so that you’re not sinking into your shoulders.
• Continue this rocking movement for 15 to 30 seconds. Take a quick breather, then repeat for 3 to 5 sets.

For an additional challenge in this exercise Novak suggests placing a yoga block in between your thighs to really engage your legs. You can also place your forearms on the flat side of a Bosu ball (with the unstable part on the ground), to incorporate an element of instability into the move. No matter how you do it, that rocking motion will put your core to the test.