We’ve all heard the phrase “engage your core” when it comes to lifting. And your core strength is crucial – we’ve written about it before – it’s the difference between a bad deadlift and a great one. Or a mediocre pushup and one with perfect form. In short, if you’re doing something that requires strength, core strength is likely to benefit you.

When you're doing squats or deadlifts, a tight core generally helps you maintain better form and avoid a rounded back, the silent killer of heavy lifts. (Your core is more than just your abs—think obliques, the muscles that allow you to bend forward or backward at your waist or connect the bones of your spine.) Still, you may have trouble figuring out what it actually means to "engage" a part of your body; bracing your abs may come to mind, but it's a little more complicated than that.

In case you didn’t know, planks are a killer core exercise, in particular, and easy to do for even the most uncoordinated of people (like me). Here’s our take on the perfect plank, though there are at least 20 different iterations, like side planks or wide-grip planks. Generally, after a day of lifting, I’ll top off my sessions with three to four sets.

Thanks to a recent Reddit thread, though, I started using planks as a warmup for squats and deadlifts. Why? Well, they’re a good way to engage your core while lifting. If you’ve never done a plank, go do one now—we’ll wait. What you just felt while planking was your core working.