How to do a reverse crunch

Master how to do a reverse crunch to build up your core and avoid injury

Reverse crunch
(Image credit: iStock)

Here’s how to do a reverse crunch and apply it to all of your upcoming core workouts for a brand new challenge. The perfect move for feeling the burn when it comes to training your upper abdominal muscles, a reverse crunch is important to master properly if you want to get build stronger abs. 

Along with sit-ups, with the knowledge of how to do a reverse crunch, you’ll be on your way to finishing your next set with finesse and making time for some crucial core strengthening exercises. Adding in a reverse crunch to your workout is a great way to prevent any muscular imbalances as you work on your core, keeping you in good stead for your next workout session. 

If you’ve imagined that ‘washboard abs’ are simply a thing of aesthetics, you might be surprised to learn just how big a part your lower abdominal muscles play in your overall mobility. You use your core to walk, run, twist and rotate in everyday life, as well as during workouts. So as well as helping you look stronger, mastering the reverse crunch can really help you get further in your workouts too. 

Simply put, a reverse crunch is the opposite motion of a traditional crunch. You lie flat on your back and crunch the lower half of your body, as opposed to crunching your chest and torso inwards. It’s important to keep your shoulders firmly on the floor or mat as you do this, as it’s an exercise that really works your core when done correctly. 

A stronger core has so many potential benefits when it comes to sport and improving your day-to-day life, according to research from Harvard Medical School. An improved core might even help with back pain, and help you to feel more mobile when it comes to stretching. If that’s enough to convince you that a reverse crunch is worth your time, then simply keep reading to find form tips and everything you need to know to make your core that much stronger. 

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, top PT and pilates instructor at F45’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
Matt Evans

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.