When we perform exercises of any kind, there’s often an instructor or coach in the background telling us to “engage our core.” But what does that really mean? It turns out there are two different ways of doing it and they produce opposite results, so it’s important to know which one you need to work on to accomplish your fitness goals.
There are two ways to engage your core
Pull your belly button to your spine
This one is probably familiar if you’ve ever done pilates or physical therapy. You’re told to pull your belly button toward your spine, or to think of “hollowing” or “drawing in” your stomach muscles. In this motion, you are still allowing yourself to breathe; you’re not sucking in your stomach, but rather, tightening it with your muscles. (If you watch in the mirror, you’ll notice your waist appears smaller when you do this. Sometimes people will also do it to pose for a picture or to create a leaner look while performing as a dancer.)
The reason this is a common practice in many physical therapy, yoga, and pilates classes is that doing so activates your transversus abdominis, one of the lesser-known ab muscles. A study in 1999 found that people with low back pain were less likely to contract this muscle while moving their bodies, so physical therapists began to instruct people to contract this muscle to protect their backs from strain.
Unfortunately, it turns out this move may not actually do much to protect your back after all, but it’s still popular advice. If you’re performing yoga or pilates moves this way, you’re in good company. That doesn’t mean you need to do it, though.
Brace before lifting something heavy
Now let’s talk about what to do if you’re lifting a heavy weight or preparing to perform some kind of forceful feat of strength. First, you’ll need to brace. (Bracing may also be a good alternative to hollowing your belly in physical therapy, but I’m not your PT, so talk it over with them.)
When you brace for a lift, you’ll do something much like if you were expecting to get punched in the gut. Try that now: you’ll probably hold your breath, contract your abs, and feel the muscles all around your waist tighten up. It may seem like you’re pulling your ribcage toward your pelvis. This activates your transverse abdominis along with everything else. (If it feels like you’re bearing down for a bowel movement, you’re doing it right.)
This is what powerlifters and other weight lifters mean when they talk about bracing for a lift. If you are wearing a belt, bracing will push the muscles of your midsection against the belt (not just in front, but all around).
This process turns your torso into a solid, stable, pressurized column that can support a lot of weight (as in a squat), or hold its position steady as you apply force to it in another direction (as in a deadlift, where your torso is the link between your back, your leg muscles applying force, and your arms, which are supporting the barbell in your hands).
Holding your breath and locking it in with a valsalva maneuver is typically part of this process. In some cases—for example, if you are pregnant or if you have certain medical conditions—your doctor may advise you not to hold your breath under pressure. You can still do your best to brace; just exhale slowly during the lift rather than holding your breath. (If you have health concerns, talk to your healthcare provider about whether this is appropriate for you.)
When you’re trying to do a heavy lift in the gym, remember the distinction between these two ways of engaging your core, and do not try to hollow your belly or pull your navel to your spine, since that will have an effect opposite of the one you want. Save that motion for pilates class; when you’re under a barbell, make sure you brace.