As the inversion of a plank, the hollow body hold is an exercise infamously known amongst gymnasts. Rather than bracing yourself against the ground and fighting against gravity, you're on your back, fighting against…well, yourself to hold the position.

Here's how it's done:

Lay down, pressing your lower back into the ground. Hinge at the hips to tuck your knees into your chest while also raising your shoulders off the ground, reaching forward with your arms. Then, extend your legs straight out and hold in position, stretching your arms back behind your head and squeezing your core to maintain your posture. If you're a beginner, keep your arms pointed forward to make the move less difficult. To start things off, hold for 30 seconds, then move things up to a minute or more once your core strength has developed.