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At a Glance Info
Targets: Abdominal wall (rectus abdominis), obliques
Equipment Needed: None
Level: Beginner
It’s something zookeepers and herpetologists have successfully kept secret for years: frogs actually have incredibly well-defined six-packs.
Okay, we might have made that up (at least, we certainly hope so), but the fact remains that frog crunches are one of the best ways for you to develop abs of steel.
These funny-looking sit ups target your entire abdominal wall (including your obliques), giving your core a complete workout in just a few sets. If you’re pressed for time, or just want to get in an effective ab workout without sacrificing an entire day to it, then frog crunches definitely belong in your exercise repertoire.
Of course, as with any exercise, doing them properly is paramount — and if you’ve never seen anyone doing frog crunches before, you may not have much of a knowledge base to build on.
Below, we’ll walk you through how to do the perfect frog crunch, so that you can see rapid gains without risking injury. A word of warning: you will look silly doing these, but if you follow our instructions, at least you won’t look stupid.
What are Frog Crunches and What are the Benefits?
To do a frog crunch, you lay flat on your back and lift your torso while your legs remain on the floor — just like in a regular crunch. The difference is that you keep your legs in a diamond shape, with the soles of your feet touching and your knees sticking out.
This position basically takes your hip flexors and quads out of the equation, as those are the muscles that most people use to cheat when doing regular crunches. As a result, your abs will have to do all the work — and they’ll definitely remind you of how poorly you treated them for a few days afterwards.
Mastering the frog crunch should improve your form in every single ab exercise you do, as it truly teaches you how to utilize and isolate your stomach muscles.
Are frog crunches guaranteed to give you a six-pack? No — your diet will play a big role in that. However, they should help you build some incredibly strong abs and improve your posture, regardless of whether you ever burn enough fat to show them off to the world.
How to Do a Frog Crunch Effectively
Frog crunches aren’t complex or difficult to do, but you still need to practice proper form if you hope to see any benefit.
Warning! You shouldn’t do frog crunches if you’ve recently given birth or had abdominal surgery. You should also talk to your doctor before making any changes to your diet or exercise routines. Also, as with any exercise, you can hurt yourself if you do them incorrectly.
With that out of the way, here’s a step-by-step guide to the perfect frog crunch:
Assume the Position
Lay on your back with your fingers at the base of your head and your elbows pointed out. Stick your knees out and slide your feet up until the soles of your feet touch.
Actively press the soles of your feet together; this should activate your hamstrings while simultaneously taking some strain off your hip flexors.
It may help to lay on a mat or some other soft surface, but don’t put any padding under your back, which should stay flat on the floor the entire time.
Lift Your Torso
With your feet pressed firmly together, raise your upper body off the ground. You don’t need to come all the way up to a fully-seated position — just getting your shoulders a few inches off the floor is fine. You’ll still feel it in your abs, trust us.
In fact, your lower back should stay firmly pressed to the mat. If you feel your back coming up at any time, you’re doing it wrong (more on that in a second).
That’s it — that’s all there is to the basic frog crunch!
Common Mistakes to Avoid When Doing Frog Crunches
While frog crunches are very simple exercises, there are quite a few common mistakes that many people — even experienced athletes — make when doing them.
One of the most common is using your arms to help lift you off the mat. Your hands should be kept behind your head, but they shouldn’t be lifting your head (that’s a great way to hurt your neck). Keep them lightly touching the back of your skull, and resist the temptation to add pressure to finish those last few reps.
Likewise, your lower back shouldn’t bow up off the floor. If you do that, it’s likely that you’re using your back, legs, arms, or momentum to complete the rep — basically, you’re working everything except your abs. If you let your lower back rise up, feel free to do thousands of frog crunches for months on end and then leave us an angry comment complaining that they didn’t work at all (note: please don’t do this).
Remember to breathe as well. Many people instinctively hold their breath when doing any ab exercise, and this puts more strain on their muscles, potentially leading to injury. Worse yet, failure to give your body the oxygen it needs could limit the gains you see from your workouts!
Finally, no matter what else you do, resist the urge to maintain eye contact with the meanest-looking guy in the gym while you do your frog crunches.
Variations for Frog Crunches
There’s one major variation for the frog crunch that’s so commonplace that many people will say it’s actually the only correct way to do them.
This variation involves lifting your knees and feet off the ground during the crunch, then bringing them up towards your upper body during each rep. Basically, your abs are pulling your head up and your legs up-and-in; it almost looks like you’re trying to kick yourself in the face.
You can keep your hands on your head for this variation, but some people also keep their arms straight and push their hands down past their groin towards their feet instead.
This variation is more difficult, as it puts your lower abs under greater strain. However, it’s also more complex, so it may not be ideal for beginners.
The beauty of this variation is that it’s basically a regular crunch and a reverse crunch all in one. That’s how it’s able to utilize your entire core, and your lower abs will be just as challenged as the upper ones.
Other variations include resting your feet on a wall, which can really help you focus on your abs instead of having to worry about what your legs are doing. You can also fold your feet completely in, like you would if you were sitting cross-legged; this helps focus the intensity on your abs, but it may not be ideal for users with tense hip flexors.
Looking for other exercises that don’t require a lot of space or equipment? Try a superman plank or burpees.