How To Do A Side Plank Crunch To Strengthen Your Obliques

Upgrade your ab workouts.

Originally Published: 
How to do a side plank crunch for stronger obliques.
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You’ve heard of side planks. You’ve heard of crunches. Now how about combining the two for a side plank crunch? This compound exercise isn’t the easiest to do at first, but it’s definitely worth the effort.

By adding the hybrid move to your workout routine, you’ll be able to target different muscle groups and spice things up. This is why personal trainer Julia Buckley says she loves dynamic plank variations like this one. While holding a standard plank works to strengthen your core, the side plank crunch goes above and beyond. “The crunch element primarily works the obliques in the side of the waist, but all your deep core muscles fire up to hold you in the position, along with your glutes,” Buckley explains. “You’ll feel a nice burn around the shoulders, too, as they work to support the weight of your upper body.”

Because you’re holding yourself up as you not only balance in a side plank but crunch with your upper arm and leg, the move is also great for improving your core stability. And core stability is a key element of functional strength training that helps you avoid injuries.

A pro tip to note: Since it’s a difficult exercise that uses multiple parts of your body, the best time to do a side plank crunch is at the end of your workout. “You don’t want the muscles that support your spine, which enable correct posture, to be too fatigued when you need them during your workout,” Buckley says. If you haven’t done side plank crunches before, go slow and follow the expert guidelines below — and keep in mind that it can take some time to perfect any exercise, especially one that requires full-body strength and balance.

How To Do A Side Plank Crunch

Here, certified fitness instructor Alayna Curry, AFAA explains how to do a side plank crunch properly:

- Start in a plank with forearms on the ground and legs out straight behind you.

- Rotate your body into a side plank, so that only one forearm is on the ground.

- Stack your legs, one on top of the other, pressing the bottom foot into the floor.

- Reach your top arm up overhead.

- Bring your top elbow down as you lift your top knee to meet it. This will “crunch” your side.

- Return your leg out straight. Reach your top arm back overhead to complete one rep.

- Do three rounds of 10 reps on each side, one to two times a week.

Side Plank Crunch Variations

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For a little more intensity, Curry recommends starting in a high plank position before turning to a high side plank and balancing on one hand. Do side crunches from this position. For an even greater challenge, she suggests holding a dumbbell in your top hand.

If you want to lessen the intensity or need a modification, keep your bottom knee planted on the ground with your foot back behind you for balance. If it’s too much, you can also leave out the upper arm motion and just focus on the knee raise element, Buckley says. Place your top hand on your waist and steady yourself on the side of your bottom knee, then crunch by lifting your top leg.

Form Mistakes To Avoid

One common mistake to avoid? Rotating your body. If you curl inward or lean too far back, then you won’t target the obliques when doing the exercise. To maintain proper alignment, Curry says to imagine yourself between two sheets of glass, so that your body remains flat within one plane.

Another mistake is drooping down in the middle, which could hurt your back. Instead of sagging, focus on keeping that top hip high, Buckley says. Remember: The right form will give you better results and that satisfying core burn.

Studies referenced:

Bliven, K. (2013). Core Stability Training for Injury Prevention. Sports Health.


Julia Buckley, personal trainer

Alayna Curry, AFAA, certified fitness instructor

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