Sit-ups, or any variation of this movement where you go into forward flexion eg when lying on your back, you bring your torso towards your knees to work the six pack muscle (called the Rectus Abdominus or RA), is considered a NO-NO for postnatal women, ladies post hysterectomy after some types of abdominal surgery, in those with abdominal doming or in diastasis recti (seperated tummy muscles). This isn’t limited to women, lifting heavy weights can cause it to happen in men too. Performing this exercise can cause more harm than good. So, if you’ve any of the above conditions and you’re doing sit ups, STOP them immediately.
How do you strengthen your abdominals? Pilates!!!
The first thing we need to do regarding this area is actually focus on strengthening your pelvic floor which is a bit like a sling of muscles supporting you from underneath, then locate the deep abdominal muscles which lie under your six-pack/R.A muscle. These deep muscles are known as the Transversus Abdominis (TA). If you work on strengthening the deepest muscles first, then focus on the next layer, then the next layer after that, then your abdominals will re-align to their original structure.
Sit-ups strengthen and work the R.A. During pregnancy with diastasis recti and after some surgeries, we know that this muscle has lengthened and separated. If you don’t have a solid foundation underneath this six-pack muscle before you work then sit-ups will actually make your separation worse, because you’re forcing the muscle to strengthen, when it’s still in a weakened, separated state. The amount of abdominal pressure placed on the six-pack muscle when performing a sit-up, forces it to separate further apart.
The best type of exercise to do for your abdominals, postnatally is Pilates-based. Pilates focuses on your pelvic floor and TA. As an instructor I’d focus on strengtheing your core first and then later on work on those sit ups to shorten the RA muscles.
So, I hear you ask: “Why do people do sit-ups?”. Well, in most cases, people do sit-ups in the hope that they will get themselves a toned, flat stomach and a noticeable six-pack. However I’d debate this, often sit-ups are not performed safely and unless you are super leaned with a strong core, they aren’t going to work.
So, to get a six-pack, there are three things you need to do: a) clean up your diet, b) make fat-burning exercise part of your routine (the best way to burn fat, is to build lean muscle eg weight/resistance training), and c) work your pelvic floor and TA by doing Pilates.