SETUP: Get on the floor and place your feet on a Swiss ball. Get your butt close enough to the ball to create a 90 degree angle with your legs & knees (hence the exercise name!).
REP: Perform a crunch by squeezing your abs and peeling your shoulders off the ground, as if trying to touch them to your knees. Notice how I’m also using my heels to push into the ball as I do the rep? This allows me to tilt my pelvis, giving a much better contraction of the target muscles!
TIP: Most people get their breathing totally wrong on crunch-based exercises. Either they hold their breath, or they breathe out at the top of each crunch. While breathing is always better than not breathing, both of these approaches are technically incorrect. Instead, I want you to breathe in before you start your rep, then start breathing out as you perform the crunch, and continue breathing out at the top until you’re short of air. You’ll feel 100% superior abs recruitment.