I did 50 butterfly sit-ups a day for a week — here’s what happened to my abs

a photo of a woman with strong abdominal muscles
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Often seen in Crossfit workouts, butterfly sit-ups offer a new take on regular sit-ups and crunches. So, when I was asked to do 50 butterfly sit-ups a day, I jumped at the chance. After all, why wouldn’t I want to throw in a new move to my core-workout repertoire?

Butterfly sit-ups are a great exercise for working the core muscles, particularly the rectus abdominis — aka the six-pack muscles, and the transverse abdominis, which are the deepest muscles in the midsection. The lower back is also activated in this exercise. l. 

Doing 50 butterfly sit-ups a day sounded like an easy feat; after all, how hard can they be? Read on to find out what happened when I took on the challenge.

How to do a butterfly sit-up 

The butterfly sit-up is much like a regular sit-up, except with some differences in leg positioning. As with all ab exercises, form is important, so here’s how to do a butterfly sit-up correctly: 

  • Sit on the ground, with the soles of your feet touching and your knees bent, knees down towards the ground. Your legs should almost form a diamond or butterfly shape.
  • Keeping your feet on the ground, lie back, arms outstretched overhead.
  • Tuck your chin into your chest, and use your core muscles to dive your body upwards simultaneously bringing your arms over and tapping the floor on either side of your feet.
  • Keeping your core engaged, lower back down to the ground. That’s one rep.

When doing butterfly sit-ups try to move slowly and not use momentum to jerk the body up — this often means you’re using other muscles, whereas, ideally, the core muscles should be doing the majority of the work.

I did 50 butterfly sit-ups a day for a week — here's what happened 

My back was in bits

On the first few days of this challenge, although my abs were fired up, my back was also paying the price. thought I had a fairly strong back, however, the repetitive motion of these sit-ups definitely hurt a little. If you struggle with back pain, I would swerve butterfly sit-ups, or break them up into sets of 10 perhaps, with a break in between. 

It’s easy to lose form

Unless you have a lot of time on your hands, and you’re willing to keep taking pauses to reset and give your abs a few moments of respite, then it’s hard to hold decent form as you work your way through 50 butterfly sit-ups. I noticed my feet were lifting from the floor, my legs kept caving in, and I dread to think what kind of shape my spine was making.  

Regular sit-ups are by far an easier choice, and if you’re a beginner, as a Personal Trainer, I’d advise sticking to these or trying butterfly crunches, where you don’t fully raise the torso up to a sit-up position. Here’s more on how to do a sit-up. 

It’s tricky to keep your feet on the ground

After about 20 reps, I noticed my feet were lifting up off the floor and I ended up putting more strain ended on my back and neck. In hindsight, I could have done with the help of a friend to hold my feet down on the ground.

My core muscles were on fire

Butterfly sit-ups are a great exercise when it comes to torching your core muscles. I could feel my six-pack muscles screaming as I moved my body from floor to sitting, and back, continually. Plus, I could feel my deeper core muscles working to stabilize my body on the way back down. Thrown in with a mixture of other exercises such as side planks, v-ups, leg raises, and planks, then these butterfly sit-ups could contribute to a great ab workout. 

Did I notice any changes in my core after doing these for a week? Well, no, but I’d likely need to do them for a lot longer to see results. Plus, it’s important to not forget that if you have a layer of fat lying above your ab muscles, then this needs to go first for the ab muscles underneath to be visible. Burning the fat that lies above the ab muscles requires being in a calorie deficit; in other words, burning more than you consume. As the saying goes: ‘abs are made in the kitchen’. Here's more on how to calculate your body fat percentage, and why it matters

Would I recommend the 50 butterfly sit-ups a day challenge? 

Overall, I can see the benefits of butterfly sit-ups, and yes they did work my abs, but would I do this again? Absolutely not. The strain on my back wasn’t nice and there’s a whole plethora of other ab-based exercises which can be done that don’t put as much pressure on the spine. 

Of course, doing a few reps of butterfly sit-ups as part of a wider ab exercise isn’t likely to be as taxing, so this isn’t a move to skip entirely. This challenge did serve as a reminder, however, that doing the same exercise day after day isn’t good for the body. As an important reminder, if you feel pain during an exercise always stop, as it’s not worth aggravating any sore muscles.

On the plus side, my abs definitely were given a beating, so this exercise is definitely one to add to your workouts if you can master and maintain the form.

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Lucy Gornall

Lucy is a freelance health and fitness journalist as well as a pre and post-natal personal trainer. Although a sweaty gym session (skipping rope is a must) is her favorite way to ‘relax’, she’s also a fan of bingeing on The Office, snacking on chocolate-coated raisins, and fizz-filled brunches with friends.