The Number One Mistake That Gives Runners an Aching Back—And How To Fix It

You may think that running is just leg day in disguise—but the truth is, you need to enlist every part of your body (and mind) to make the miles ahead of you be the best they can be. The core is one of the integral parts of the body for pacing faster miles, and if you cross the finish line with some major back pain, Nike Master Trainer Traci Copeland says a lack of ab work may be to blame.

On this week’s episode of Trainer of the Month Club, Copeland (our trainer for Well+Good’s United States of Running 5K and 10K Program) leads you through three sets of five core moves that she’s begging every runner to do at least once or twice a week. Why? Your core wraps all the way around your back. So if your runs are leaving your posterior chain feeling sore and achy, it’s possible that these muscles aren’t fully activated.

“A lot of times runners are getting back pain, but the back pain isn’t from having a bad back. It’s probably related to core strength, so you want to make sure your core is properly firing up every time you stride,” says Copeland. Let’s do a quick roll call on all the muscles in your torso that propel you forward on the run—shall we? “Your core technically includes your pelvic floor muscles, your internal and external obliques, rectus abdominis, and all the other superficial layers you think of when someone says six-pack, the erector spinae and multifidus, which are in the back, and all the deeper, smaller muscles in your trunk,” Alena Luciani, MS, CSCS and founder of Training2xl, previously told Well+Good. That means that the muscles surrounding your belly button don’t even account for half your #coresquad.

So what do you do to make sure all 360 degrees of your torso support you as the miles tick by on your smartwatch? You work every inch of your midsection—but in the right way. As Copeland points out in this week’s core-centric episode, your form matters even more than the number of reps you do in moves like crunches, shoulder taps, and bear walks because that will directly translate to how well you keep engagement strong while you run.

Dead bug is one example of when your form will either hurt or better your runs ahead. To get into the move, lie down on your back and extend your arms straight up and keep your legs bent at a 90-degree angle. With control, lower one foot to hover just above the ground, bring it back to the starting position, and switch sides. However, Copeland says she often sees one mistake here that makes the move a lot less effective. “I make sure that every part of my back is connected to the ground. That’s the most important thing here,” she says. Keeping your back to the ground ensures you’re not putting your low back at risk of injury; you’re strengthening its muscles instead.

To read more about how you can be intentional with your running core movements, watch the full video (and learn some new moves in the process).