Why Real Strength Begins With the Core

Credit: Photograph by Karan Kapoor

Not so long ago, the nearest a personal trainer would come to talking about the core was telling clients to beef up their six-packs with an ab-numbing series of crunches. Nowadays, if they gave out awards for the most repeated exercise jargon, core training would take gold. Whether you're in a CrossFit, Pilates, or random "core focus" class, you've probably heard the C-word ad nauseam. But though it might permeate pop fitness culture, do you really know what core training is?

"The core has been misinterpreted for 30 years as being all about aesthetics," says Michael Ryan, a certified master instructor at Equinox gym in New York City. "Now we're learning that you really can't achieve serious functional fitness if you don't train the core properly."

That's because the muscles of the core form a dynamic link between your legs and arms, making them key to athletic performance, resistance to injury, and an aligned posture that allows you to move through your day without a tweaked neck or aching knee. That's not just trainer-speak, either. A 2012 study in the journal PLOS ONE found that targeted core training produced quick relief from back pain. And a 2013 Japanese study showed substantial gains in vertical jump among soccer players who performed a basic core workout three times a week.

And while you can find dozens of different (and conflicting) methods to help you put on more muscle or run a faster marathon, when it comes to strengthening the trunk, there's one clear road map. Top strength coaches and physical therapists alike now tend to agree on the most effective exercises to build the core you need. And you can get that job done without doing a single crunch.

But first you'll need to know what it is you're actually working. "Think of the core as your entire torso," says physical therapist David Reavy, who works with NFL and NBA stars at his Chicago clinic, React. That includes the skeletal scaffolding of your spine, shoulder blades, pelvis, and hip joints, plus all the muscles that support and move that scaffolding. Which means that your butt, your back, and even the muscles at the top of your shoulders are all part of your core. These muscles fall into two categories: stabilizers, which hold your spine and pelvis in healthy and comfortable alignment and allow you to brace and stay steady when, say, you catch a heavy medicine ball or hold a plank. And mobilizers, which get your torso twisting, turning, flexing, and folding. If any of those muscles become weak, tight, or out of balance with the other core muscles — pretty much guaranteed if  you spend all day between a car and a desk and a dinner table and a couch — the entire system can fall out of alignment. Keep those muscles talking and working together, though, and you get a trifecta of benefits.

Instant Workout Gains

"Every bit of force you generate — I don't care if that's pushing off the floor to jump for a basketball or lifting a barbell overhead — has to get transferred through the core," explains Ryan. "Think of the core as a transductor of force, a conduit." So each time you plant a foot during a jog, muscles in your foot and leg push at the ground to create a force that travels up your leg and through your hip joint into your pelvis and spine. If that force encounters a pelvis and spine held tight in good alignment by strong core muscles, the energy does what it's supposed to: propel you forward. But if that force encounters bones left wobbly by weak, soft core muscles, much of that energy dissipates. And the result? You're slower. (A 2009 study in the Journal of Strength and Conditioning Research confirmed this by putting a group of healthy adults through a core-stability training regimen. After six weeks, the runners had sliced 47 seconds off their 5K times.) This same concept applies to strength training, too. Build a stronger, more stable core and you'll squat, push, pull, and row more weight, more efficiently.

Fewer Injuries

If you've ever had to quit running because of knee pain, take a few weeks off tennis because your back hurt, or abandon the bench press thanks to an aching shoulder, you've already experienced the downside of a weak, imbalanced core. Knee pain often has less to do with pounding the pavement than with weak abdominals — not just the six-pack, either, but the deep, thick ab muscles like the transverse abdominis — which let the pelvis tilt forward, and which cause your leg bones to rotate inward, putting a twisting force on the knees. Back pain from tennis can be a simple matter of lower-back, glute, and hamstring muscles weakened by sitting all day. And the bench-press issue — or any example of abandoning an upper-body exercise because of shoulder pain — is a classic case of weak upper-back muscles allowing the shoulder blades to drift out of position, making your shoulder joint vulnerable. Good posture and a strong core cure all these ills and more, which is the reason FIFA, the international soccer federation, designed and implemented a basic core-training program that a 2014 study in the International Journal of Environmental Research and Public Health found reduced injury risk by 35 percent in players all over the world.

Life Gets Easier

Upper-back tension from staring too long at a computer or knee pain from squatting to play with a kid — these stem from bad everyday posture and not knowing how to fire the core muscles that support the right positions.

"The positions you put yourself in dictate your core function, and that dictates the way you feel in your body," says Ryan, who recommends learning what he calls core awareness: the conscious ability to maintain good, healthy posture by firing the right core muscles. For example, when sitting at your computer, consciously remind yourself to pull your chin back so your head is stacked directly above your spine (which might eliminate any headaches you've been having) and to pull your shoulder blades down and squeeze them together to eliminate a slouch. Or when you're standing in line or walking up stairs, concentrate on contracting your glutes and tightening your abs to put your pelvis in a neutral alignment; this takes pressure off your lower back and keeps your glutes firing properly. All these simple adjustments make it clear why, when Reavy has a client ask what he can do to keep his body healthy, his reply is always, "Start by focusing on your core."

Test Your Core Strength

There's a simple way to know if you have a rock-solid trunk: Get into a push-up position with a PVC pipe or a broomstick resting on your back, so that you have contact at your head, between your shoulder blades, and on your butt. Perform a push-up with back and hips aligned until chest hits floor. "To keep the stick in place, you need every core muscle to engage," says Equinox Tier X coach Michael Ryan. Your goal: five perfect reps. If the stick wobbles or falls off, you've got work to do.