Why do it: It won’t make you huge, but it will work your multifidus muscles, which live around your lumbar spine and keep your lower back stable. “This is where people tend to feel their injuries,” Boschen says. Building strength here is crucial for keeping those 40-something-and-I-lifted-something-heavy aches and pains at bay.
How to do it: Lie facedown on the floor with your legs straight out behind you. Engaging your core and keeping legs straight, lift your legs off the ground and hold them aloft for at least three seconds. Boschen says what you do with your arms changes the difficulty of the move. If you're a beginner, cross your arms against your chest. Once you have that down, hold your arms perpendicular to your sides. And finally, try holding your arms out in front of you, upper body lifted off the floor. Add arm and ankle weights if that still isn't enough.