We’ve all done them (or been forced to do them) somewhere along the line. Whether it was during fitness testing in phys ed class, by a trainer, in a bootcamp or from a coercive magazine article. What nobody told us was that this exercise might actually be harming you and putting you at risk for back problems.
What exercise am I talking about? The infamous sit-up.
Let’s be clear- I’m not talking about a crunch. A crunch and a sit-up are very different when it comes to the specifics. The sit-up I’m talking about is either the kind where you’re knees are bent and you’re curling up towards your knees with your arms behind your back- or your legs are straight and you are bending your torso to get up from the ground- sometimes with your feet locked in or stood on by a gym teacher, trainer, or gym buddy.
We’re told that these are the path to our glorious 6-pack. Magazines, fitness groupies, and any “professional” that doesn’t have a year or two of education shout this “fact” (myth) from the rooftops of gyms all over the world. But, it is just that.. a myth.
The first reason this exercise WILL NOT grant your wish of an Arnold worthy torso: Sit-Ups don’t actually work the core or abs.
WHAT! I know. Shocking.
Sit-ups, especially the kind where you lock your feet in and have straight legs, actually work the hip flexors. When you think about it- this makes sense. All you’re doing is bending at your hips…
Even the sit-ups where you have your knees bent only work the core for a very short range of motion.. after that, it’s back to the hips. You know that aformentioned crunch exercise? Where all you do is lift your chest and shoulders up and then come back down the the ground? That’s the range of your abdominal muscles (specifically the rectus abdominus group- the muscle you see glistening in the form of a 6-pack on all sports illustrated models). Past that little raise off the ground- it’s your hip flexors doing the work.
Second reason sit-ups won’t give you abs- there is no such thing as toning one part of your body. Getting that 6-pack look comes down to many factors, and certainly strong core muscles is one. The truth is, we all have abs- some more visable then others. Aesthetically, it comes down to your percentage of body fat, water retention, and lastly muscle mass (and even genetics) as to how obvious or view-able that 6-pack is. The HEALTHY body fat percentage for females is no lower then 18%. Guys can get down to 12% in a healthy scenario. When you see models or athletes with that 6-pack look- especially in a photo-shoot scenario- there’s a lot of other factors going on. Diet, for one. Photo-shopping for second. Notoriously fitness models dehydrate themselves and eat a very strict diet leading up to competitions or shoots- for that added lean, muscled look. They do not upkeep that standard for a long period, if they are healthy. It is for aesthetics ONLY.
I’m a huge advocate for core training and strength- but you will never find me pushing my clients to get a 6-pack. They already have one. We all do.
Now, why and how are sit-ups actually harming us?
Because they combine excessive hip flexor work with a curve through the spine.. they have two big risk factors. The hip flexors, specifically the psoas major, attach onto the lumbar spine. If they are tight- they can pull on that spine creating a shearing force in the discs and vertebrae. This causes degeneration over time and puts you at risk for injury and chronic pain. Secondly- if the spine is consistently curved, not only is there already a shearing force in the spinal column, discs are being compressed which can lead to degeneration as well. Add this to hip flexors pulling from the other side- you get a recipe for bad things.
If you already have a history of low back injury or pain- sit ups are probably not something you want to play around with. If you’re healthy and no known issue- doing sit-ups may not kill you, but they’re definitely not doing what you think they’re doing.. and there is better ways to get actual core benefit.
Because the rectus abdominus only has that small range of motion, doing crunches- or specifically the McGill Curl-Up exercise are much better ways to work your abs if that’s your goal. Your abs and spine will thank you for this!
So next time you hear someone preaching about how great sit-ups are.. autocorrect in your head that they are really talking about your hip-flexors, not your abs, and that nobody really needs tighter hip flexors! Especially us equestrians. Our hips are usually tight enough as it is. Train smart!