How to do a reverse crunch

Discover how to do a reverse crunch properly and work your core

Reverse crunch
(Image credit: iStock)

Learn how to do a reverse crunch properly and gain an essential skill, as well as toning up your abs. This exercise is one of the very best for working your rectus abdominis (the muscles that form a six-pack) and your obliques (which are down the sides of your stomach area). Building stronger abs is a goal for many on their fitness journey, so it’s no wonder reverse crunches form some of the best abs workouts around.

In the process of mastering how to do a reverse crunch properly, you’ll learn that this particular ab move, alongside many others, won’t just help you reach the aesthetic look you’re after. It will also help you to strengthen your core massively which is a part of your body used for so many everyday movements. With a reverse crunch in your arsenal, you’ll move through ab workouts in an easier way, and build up to bigger fitness challenges. 

Of course, a strong core as a result of reverse crunches and similar moves (like a sit-up), will make things such as walking, running, and stretching easier. So, keep reading for all the advice you need to master it, as well as what to make sure you avoid. 

How to do a reverse crunch

Reverse crunch

(Image credit: Future)

This hip flexor and core strength ‘crunch’ variant makes your lower body muscles do the work. 

  • Lie flat on your back with your arms by your sides, palms on the floor. Make sure your abs are drawn in and your legs and feet are together.  
  • Without moving your upper body at all, raise your hips and pull your knees towards your chest, bending them in the process. 
  •  Return to the starting position to complete one repetition. 

How to do a reverse crunch: Common reverse crunch mistakes 

Reverse crunch

(Image credit: iStock)

Reverse crunches are a simple move to learn, but difficult to master: any exercise reliant on curving your spine repeatedly has the potential for injury. You need to be careful when performing this move, as it’s not suitable for pre-existing sufferers of lower back pain. 

When it comes to maintaining perfect form, there’s a few things to bear in mind. “Ensure your legs are in a 90 degree position so that your shins are parallel to the floor”,  says Sam Hull (opens in new tab), top PT and pilates instructor at F45 (opens in new tab)’s Tooting branch. “Exhale as you engage your lower abs. Hold for a beat at the top of the movement and then slowly roll back through the spine to the start position. 

“When performing the reverse crunch, it also helps to engage your glutes and press your arms into the mat.” The instability of the movement can provide an additional challenge: as you struggle to keep yourself steady using only your core, it helps to work your abdominal muscles even more. Therefore, it’s important to do the move slowly and under control in order to get the most from this muscle-building move. 

 Variation: Reverse crunch kick-up 

Reverse crunch

(Image credit: Future)

If you’re feeling adventurous, try this variation on the classic reverse crunch – it adds in a dynamic kick for a greater cardiovascular workout.

  • Lie flat on your back with your arms by your side, your core braced, your legs together – bent at the knees – and your feet flat on the floor. 
  • Raise your hips and pull your knees towards your chest to perform a reverse crunch. 
  • Keep the movement going by kicking your legs out straight. As you extend your legs straight, your lower back should raise off the ground and your backside should be in the air. As you finish this movement, the tips of your toes should be in line with the top of your head. 
  • Return to the starting position to complete one repetition. 

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Matt Evans
News Editor

Matt Evans is an experienced health and fitness journalist and News Editor at Fit&Well, covering all things exercise and nutrition on the Fit&Well website. Matt originally discovered exercise through martial arts: he holds a black belt in Karate and remains a keen runner, gym-goer, and infrequent yogi. His top fitness tip? Stretch.