So long as you’ve built up some baseline level of mind-body connection, you might have a sound idea of which muscles you’re tapping during a specific exercise. You know that, for instance, deadlifts call on the backside of your legs because they always leave your hamstrings sore. Or maybe you can feel your pecs light up as you perform a fly.
What’s not so clear: Your core is always at work in the background, regardless of the movement. In other words, every exercise you perform is technically a core exercise—if you do it properly.
Experts In This Article
Daniel McKenna, CPT, former Peloton instructor and founder of The Irish Yank Society
Khetanya Henderson, CPT, a certified personal trainer, 600-hour comprehensive Pilates instructor, and 200-hour yoga teacher
Meghan Sak-Ocbina, DPT, ATC, CSCS, a physical therapist, certified athletic trainer, and strength and conditioning specialist
Natalie Ribble, MS, CSCS, CFSC, a strength and conditioning specialist and functional strength coach in Seattle
Your core at work during exercise
You can think of your core as a cylinder that sits in your midsection, says Meghan Sak-Ocbina, DPT, ATC, CSCS, a physical therapist, certified athletic trainer, and strength and conditioning specialist. At the top is your diaphragm, the body’s primary breathing muscle. The front of the cylinder is the abdominals; there’s the transverse abdominis (the deep core muscle that runs across your waist like a corset), the rectus femoris (aka the “six-pack” muscles), and the external and internal obliques (which sit on the front and sides of your waist).
On the backside of the cylinder are the multifundi (tiny muscles deep in your back) and the erector spinae (which run alongside your spine). At the bottom lies the pelvic floor, which plays a crucial role in pressure management, Sak-Ocbina says.
Noticeably, these muscles work hard during classic core movements such as planks, leg lifts, and bird dogs. But less obvious is their activation during exercises that aren’t so core-specific. “With squats, deadlifts, and other exercises where you’re thinking about using your legs or your back, for example, the core is involved in being able to execute those movements with strength and without pain,” Sak-Ocbina explains. “From a performance standpoint, [the core] is very important as well.”
1. It supports pain-free movement
That pain-free movement benefit stems from the core’s ability to stabilize and protect your spine (plus your internal organs) and support a healthy posture. Consider a barbell back squat. Your core is in charge of maintaining a neutral spine while the load of the bar attempts to compress it, Sak-Ocbina says. Without support from the core, the spine may be put in a compromised position. In the case of an overhead press, a relaxed core may cause more spinal extension (think: pressing your stomach forward and arching your lower back). Both of these compensations can lead to back pain and, in some cases, injury, she notes.
“Whether you’re lying down, sitting up, jumping up, whatever it is that you’re doing, you’re collecting those core muscles to help stabilize your entire body,” says Khetanya Henderson, CPT, a certified personal trainer, 600-hour comprehensive Pilates instructor, and 200-hour yoga teacher. “So it’s being used throughout every single exercise.”
2. It enhances stability and balance
Your core lights up when you’re unstable, helping to keep you upright, says Daniel McKenna, CPT, a New York-based fitness trainer and the founder of The Irish Yank Society. Imagine you’re carrying a baby in one arm and your groceries in another as you climb up your apartment building’s staircase. You already have to deal with two different loads on each side of your body, and the jaunt up the stairs adds an element of single-leg movement, he says. A strong, stable core prevents you from swaying to one side and toppling over.
The same idea applies when you’re on the stair climber or performing step-ups at the gym. It even factors in during single-leg exercises, like lunges, Henderson says. “If you’re standing on one leg, you’ll be able to maintain a stronger balance for much longer if you connect to your core,” she says.
3. It transfers force and boosts its production
What’s more, the core helps coordinate movement—and, in turn, transfer force—between your upper and lower body, says Natalie Ribble, MS, CSCS, CFSC, a strength and conditioning specialist and functional strength coach in Seattle.
Think about a thruster: The power is created by your legs, your arms help float the dumbbells overhead, and your core acts like the control center for the movement. The force from your lower body travels through your core and is relayed to the other half of your body to complete the exercise, Ribble explains. Without proper core activation, you may not be able to safely do the move with as much speed or as heavy of weight.
This performance boost from core engagement is also related to the law of irradiation—the idea that when you’re contracting a muscle hard enough, you’re also recruiting neighboring muscles, which enables you to produce even more force, Sak-Ocbina says.
Say you’re doing a pull-up. If you squeeze your hands tight on the bar, you’re able to better activate your forearms, biceps, and lats, giving you a stronger pull. The same idea applies to the core, Ribble says. “If you’re pulling dead weight with a pull-up or you’re not engaging your core with a deadlift, then you’re not going to be able to generate as much force just because you’re not as stiff and stable,” she says.
How much does ‘background’ core training count?
Some people get enough core training just from their compound exercises (a movement that works multiple muscle groups at once) and may not feel like they need to practice direct core exercises like planks, crunches, and Paloff presses, Sak-Ocbina says. So long as you’re lifting heavy enough, your core has to work really hard to execute those movements, she says.
Still, by and large, it’s valuable to incorporate independent core training into your routine, according to the experts. As a physical therapist, Sak-Ocbina has found that a lot of folks don’t have a strong connection to their core, have less-than-ideal breathing mechanics, are dealing with pelvic floor dysfunction, or a combination of all three. Prioritizing core isolation exercises lays essential groundwork; it gets people familiar with the process and sensation of activating their core without the distraction of trying to contract other muscle groups.
Many people spend the majority of their day sitting or lying down, so the core consequently spends more time in a relaxed state, especially compared to someone who does manual labor or is up and on their feet for hours at a time, Ribble says. With a more sedentary lifestyle, you may not be giving your core enough love if you’re just training it via compound movements.
“After we’ve gotten [people] to feel what it feels like to really connect with their core, then we put it back into those big movements—that’s where you really get a lot of benefit because that’s obviously where you can load the body the most but [they] also [are] the most functional, relevant-to-life type movements,” she says.
Plus, “making sure that we do intentional core training is going to help us be stronger through all those other movements and be able to do those movements heavier and more safely,” Ribble says.
To balance the two, McKenna suggests adding a five- to 10-minute core-specific circuit on to the end of your strength-training workouts. “In my opinion, you can do that as many times a week as you want, as long as it doesn’t take away from your other workouts,” he says. If you’re training your core so hard that you’re not able to lift as heavy or move weight as quickly the next day, that’s a sign to ease up on the isolation exercises, he advises.
Ideally, those isolation exercises are functional, meaning they mimic how you move in your everyday life, according to the experts. Your core’s main function on a day-to-day basis is to stabilize, so choose anti-rotation, anti-lateral flexion, and anti-extension exercises such as planks, dead bugs, Paloff presses,…
