Here’s How To Plank Properly And Engage Your Core Correctly

If you have a floor, you can strengthen your deep abdominal muscles as well as your hips, quads, glutes and shoulders.

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A group of adults attending a fitness class outdoors hold a plank position. The participants are arranged in a line as they do strength exercises.

Photo, iStock.

When it comes to planks there are no excuses. No time? It takes seconds. No fancy equipment? If you have a floor, you can strengthen your deep abdominal muscles as well as your hips, quads, glutes and shoulders with great, agonizing efficiency. But—and this is a big caveat—you need to plank correctly. Without good form, you risk injuring your lower back, wrists or shoulders. So as I work up to an ambitious two-minute plank (a number I plucked out of the air as it sounded challenging yet doable), I called Leslie McKernon, a certified personal trainer and co-owner of Vagus Fitness in Calgary for a pep talk.

First off, why is core strength so important?

It’s the basis of every movement we make, whether it’s shovelling snow, reaching into the cupboards, swinging a golf club or playing with our kids. If you don’t have good core strength you can’t do a lot of things—you definitely can’t do any heavy lifting. And when you engage it correctly, the effects can be phenomenal. It improves your posture, which helps keep the lower back strong. It may help with post-partum healing, a weakened pelvic floor and the little accidents that can happen. Your core helps you maintain your balance if you slip or are about to fall. In fact, I’d say that, along with mobility and flexibility, core strength is the most important thing to maintain as we age.

So how do you engage your core correctly?

You know how they always teach us to do Kegels? That’s probably one of the most superficial movements to do because that’s an external movement. To strengthen the internal muscles of the core and pelvic floor, you have to envision pulling the front pelvis muscles up, not in. Try it out while you’re standing—you will look taller and thinner. And you can do it anywhere. If I’m standing in line at the grocery, I’m engaging my core, I’m engaging my glutes. But one of the best ways to improve one’s core strength is planking.

Is that why it’s so hard to plank?

It’s not only engaging your rectus abdominals, it’s engaging your obliques, deep intercostal muscles and the transversus abdominis—the entire core section. And you also have to use your stabilizers—your shoulders and your triceps, depending on what type of plank you’re doing. But a plank is only effective as long as you hold good form. You need to know how to engage the right things. Hip flexors are the bullies of the core; they will take over. If you give them an inch they’ll take a mile.

How do you keep good form?

First of all, shoulders have to be completely in line with the elbows in a forearm plank, or in line with the wrists in a pushup plank. Otherwise, if you’re too far forward it’s hard on your shoulder’s rotator cuff, and if it’s a pushup position, it’s going to be hard on your wrists. Feet are about hip-width apart. Obviously, you need a flat back; make sure the hips are down so that everything is level. If you find that your shoulders are fatiguing faster than everything else, it means your hips are too high and all the pressure is sitting in those shoulders. Imagine a spear is right underneath your belly button and you have to hold that up.

Once I’m in position, what should I think about?

Breathing, a lot of people forget to breathe. And make sure everything is in line, and then think about pulling everything up and in and keeping everything tight. Think about being as strong as you can be. Do a checklist, go head to toe. Is my jaw relaxed? If your head buoyant? Reach the crown on your head forward. Are you still open through the front of your chest? Check that your shoulder blades are strong and pulled down, and that your core is still nice and tight by knitting your belly button toward your lower ribs. Are you relaxed through your hip flexors? Give a slight inner rotation to your upper thighs. Are your hamstrings and glutes engaged? Are you kicking out through your heels? Think of magnetizing your wrists or elbows toward your feet, as if you could drag them toward each other. Kill more time by doing the checklist back up the body.

It’s obviously a challenging exercise, but how much of it is mental?

Your body can do at least 10 percent more than your mind thinks you can. You always have more. Tell yourself, “Okay come on, you can finish that. You can do five more seconds.” And once you do that five seconds, well you can do another five seconds right? If you’re shaking, it’s working and you have to push through, breathe through it—that’s when the magic happens.

Originally published May 2018; Updated May 2019.