It’s generally wise to master the standard form of an exercise before you move on to any kind of variation. When it comes to the crunch, though, you can skip right ahead to the reverse form of the move.
As we’ve pointed out before, the standard crunch isn’t the best move for anyone looking to strengthen their core or carve out a six-pack. They can be bad for your lower back and have little impact on your lower abs. In contrast, the reverse crunch hits all the showy exterior abs muscles you need to work for a well-defined six-pack, placing particular emphasis on the lower abs. The reverse crunch also puts your abs under tension for a long period of time, maximising the benefits to your stomach muscles – if it’s done properly…
Start lying down with your arms by your sides. Raise your legs so your thighs are perpendicular to the floor and your knees are bent at a 90° angle. Breathe out and contract your abs to bring your knees up towards your chest and raise your hips off the floor. Hold for a beat in this position, then slowly lower your legs back to the starting position.
Moving slowly with complete control is key to the reverse crunch. This keeps the abs under tension for a longer period and prevents you from putting strain on your lower back, which can happen if you rush the reps. If you’re arching your lower back when lowering your legs, that’s a sign you’re not moving in a controlled fashion.
Medicine ball reverse crunch
Place a medicine ball between your knees and hold it there throughout the exercise. The weight enhances the muscle-building benefits of the reverse crunch and will also help ensure you are performing the exercise with control.
Seated reverse crunch
Sit on a bench and lean back until your torso is at around at 45° angle. Hold your feet out in front of you and grip the bench with your hands for extra support. Draw your knees up to your chest, then slowly lower them. This variation increases the challenge to your lower abs while enlisting other core muscles to help you maintain your balance.