Sit-ups, or any variation of this movement where you go into forward flexion ie when lying on your back, you bring your torso towards your knees to work the six pack muscle, is considered contra-indicated for pregnant (and postnatal) women.


Contra-indicated means, performing this exercise can cause more harm than good.  So, if you’re doing sit ups, or know a pregnant friend who is, STOP them immediately, because it’s not safe for many reasons, ok?


First of all, lying on your back to exercise during pregnancy is quite unsafe.  


Secondly, I need to let you know what your six-pack muscle (Rectus Abdominis) does during pregnancy to help you understand a little more about the anatomy changes that occur and why sit ups therefore aren’t safe to perform during pregnancy.


So, to accommodate bump at the front of your tummy, your six pack muscle lengthens, vertically.  Then, as your pregnancy develops, and your baby grows and your bump gets bigger, this muscle starts to separate around your belly button.  This is called abdominal separation.


Abdominal separation doesn’t occur in every pregnancy, by the way, but if you’ve ever done a sit up (before getting pregnant), you’ll realise that the exercise in itself works the six pack muscles.


If you do sit ups during pregnancy, it can actually cause abdominal separation, because sit ups work the six pack muscle, which as I explained is in a weakened lengthened state.  Doing strength work, like a sit up to your six pack muscle will give your tummy muscles no choice but to respond by separating.  The force applied to the six pack muscles (and your pelvic floor for another matter!) when performing a sit up during pregnancy is a considerable amount, so they’re best avoided.


As an Ante/Postnatal Fitness Expert, the best type of exercise for you to do to your abdominal unit should focus on:


a)    your pelvic floor – which is a bit like a sling of muscles supporting you from underneath, and

b)    the deep abdominal muscles known as your “core” – which lie under your six-pack muscle.  These deep muscles are known as the Transversus Abdominis (TrA).


Never fear – you can work your abdominals safely whilst pregnant.  In fact, keeping the abdominals in shape during pregnancy is a must to help with things like back and pelvic pain, and it’s specifically important that you keep the TrA and pelvic floor muscles challenged in a safe and effective way by doing Pilates or core-based exercise.


After birth, sit ups should also be avoided too, for this same reason.  Ante/Postnatal Instructors follow a system for their postnatal clients which involves locating the TrA first.  We set strengthening exercises, along with lots of focus on the pelvic floor.  Once strength in these muscle groups has been gained, work is then done to help “shorten” the six-pack muscle (because it still remains lengthened, remember), and finally finishing with “strength” work.

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.  I’m here to tell you that doing sit-ups AREN’T going to help you (as a pregnant or a postnatal woman), or anyone you know, male or female, get that six-pack you’ve always strived for.  Your body needs to be extremely lean to do this eg very low in body fat, and, you guessed it, the foundation eg your TrA needs to be toned!  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 TrA by doing Pilates.


And there you have it!  My top tips for training the abdominals for mums-to-be.  It’s important you stay active during pregnancy, but performing the wrong types of movements whilst pregnant can be harmful.  If you’d like to do a workout in the comfort of your own home, safe in the knowledge that every exercise catered for pregnancy, click here.