Ever heard someone complain of backache, only for the immediate response to be “you need to strengthen your core to support your back”? The first thing that comes to mind for most is traditional “crunches” or “sit-ups”(below image) – the number one thing you shouldn’t be doing if you suffer with back pain. The intention is romantic, but the reality is a horror story for your spine.
Traditional sit-ups assist to strengthen the hip flexors and rectus abdominus (“six pack muscles”) muscles. When you look at the anatomy of the hip flexors, you can clearly see that the origin (starting point or attachment) are at the lumbar spine, and the insertion (end point or attachment) are at the lesser trochanter of the femur (top of the thigh bone), (see below image). Now imagine if you had to tighten that muscle, where do you think that tension would translate? Your lower back of course!
The sad reality of the modern western world is that most of us are chained to a desk for 8 hours plus per day. If you didn’t already know, sitting is the new smoking – it’s one of the main culprits for chronic hip flexor stiffness and resulting lower back pain. A good example of what is happening to your back when you are sitting is this: imagine you were holding a large watermelon in your arms, with your elbows bent at 90 degrees, and then you had to sustain this position for 8 hours plus. Your arms would just about “fall off” right? Well this is pretty much exactly what is happening to your hip flexor muscles when you sit for prolonged periods. Added to this, prolonged sitting de-stabilizes the Sacro-lliac joints (the joints between your sacrum and pelvis), which explains why we can sometimes get pain in the lower back or sacrum area.
Traditional crunches have added speed (often with uncontrolled momentum) and load (weighted/body weight/resistance), which increases the shearing force on your poor lower back. There are two ways to train your stomach muscles: high load and low load motor control training. Low load motor control training involves slow, precise movements which must be sustained for at least 2 minutes or longer per exercise. An example of this is here below, lay supine on a long foam roller, elbows off the floor, raise one leg slowly and maintain continuous core activation while balancing. If you can’t manage this without falling over, you’ve failed a crucial and fundamental core stability test, and it’s safe to say that you do indeed have a “weak core”.
However, if you persist in practicing exercises like in the above example, you will target the correct muscles (core stability muscles) which do support your back, and (bonus) flatten and shape your tummy. These muscles are: the transversus abdominus (TA), multifidus, pelvic floor, posterior fibres of the illiopsoas and diaphragm (see below image), and for global stabilizers: the internal & external obliques. The TA is shaped like a corset and acts like a back brace, funnily enough exactly like the ones Olympic weight lifters use when lifting heavy weights in order to protect their lower backs. Thankfully, mother nature gifted us all with these built-in back braces. Now, it’s just a matter of practicing intelligent exercise to make that natural back brace strong in order to meet our full potential.
Most exercises fall into two main categories: high load and low load motor control training. A traditional crunch will fall into the high load category, while the above foam roller example would fall into the low load category. Whenever an exercise has added speed or load it automatically falls into the high load category. Why is this relevant? Well, to answer this we must also understand that there are two main categories of muscles: stabilizers and mobilizers. Stabilizers “stabilize” joint systems – they create stiffness in order to prevent unwanted movement in a particular joint system. These are the ones that you need to support your back, improve posture, endurance and injury prevention. Mobilizers create “motion” – these are the ones you need for strength, speed and power. We need a good balance of both stabilizer and mobilizer strength to create equilibrium in the body. A good analogy is to imagine our muscle systems as a computer: both updated software (low load motor control) and hardware (high load motor control) are needed to have a fast and efficient PC (your muscular system).
The problem is that sit-ups/full crunches are not low load – they are high load, therefore you cannot correctly state that crunches have anything to do with core stability. A traditional sit-up will only strengthen the mobilizer muscles, where the previously weak core stability muscles will remain the same. For example, let’s say your core stability muscles rated a 2/10 score (10 being strong, 0 being weak) and your global muscles rated a 2/10 score. You then practiced sit-ups to “strengthen your core”. After a month of regular sit-up practice this might result in your global muscles possibly increasing to 5/10 score, however the core stability muscles would remain at the original 2/10 score. The ratio of global vs local motor control has not improved to your favour. You are therefore left with an even greater strength imbalance than when you started, plus your backache hasn’t dissipated. Sit-ups are the exact opposite of what is required to help you achieve a “stronger core”. Because of this massive fitness myth, crunches are being prescribed to help get a “stronger core” but nothing could be more far-fetched.
Think about it this way, if you can’t balance on the foam roller with both elbows off the floor and one leg in the air, with no added speed and no added weight to add any difficulty, then how do you think your poor joints and spine will cope when you are thrashing around in cross-fit, lifting a heavy barbel over your head, or running up the mountain, or picking up your child? Your stabilizers fail in that they don’t activate at the right intensity or timously, or at all in severe cases (as with some spinal disc injuries). The body has a large capacity to deal with wear and tear, however once a certain threshold has been reached, then you have exceeded tissue tolerance. This is when simply bending over to pick up a pencil off the floor results in pulling your back out and you’re left in pain for days or weeks. This is what exceeding tissue tolerance means. It’s the straw on the camel’s back, literally.
There are 5 main categories of fitness: cardiovascular, strength, flexibility, sports specific and core stability training. In many cases, core stability is misunderstood, neglected and often left out of a weekly fitness routine. Like any of the five categories, fail to practice and you quickly loose it. In contrast, regular practice of core stability builds a strong foundation towards improved strength, speed and power – without the high price tag of injury.
The interesting thing is that you can pass high load motor control tests while simultaneously failing low load motor control tests. For example, a very fit runner can run for kilometres without tiring, however he/she cannot stand on one leg with his/her eyes closed for a full minute. This person also doesn’t stretch or partake in any other of the other 5 catergories of fitness (above). This person has strong global muscles however fails at core stability. While he/she may not currently be in any pain, there is a strong chance that there may be a time when they exceed tissue tolerance and an injury occurs. This is often the case with many active people, who go about their daily lives until one day, whoops, you make a strange turn and your neck ceases up, or you bend down in the shower and your back is pulled out, or you throw a small ball to your dog and your shoulder dislocates (this is an actual true story). No, it’s not simply old age, there is an underlying cause of misuse of the core stability muscles, joint mobility, poor flexibility, poor sustained posture, compounded over years, and your poor body has finally exceeded tissue tolerance. In some cases it is anatomical difference or injury that has caused the pain, but in most cases it is poor lifestyle choices. Rather than being angry at your body or envious of your 20’s, recognize the amount of neglect you might have given to mindful, slow exercise such as yoga, Pilates or those rehabilitation exercises your Physiotherapist gave you but you didn’t bother doing. The good news is, it’s never too late to start with gentle core stability exercise, no matter your age. Prevention is always better than cure, choose exercises that are sustainable.
Look at exercise choice as a matter of value vs cost. Sit-ups have a high cost (potentially damaging to your spine) with very little value (hip flexor & rectus abdominus strength). Whereas an elbow plank (image below) has high value and low cost. In the elbow plank you are working virtually all your stomach muscles, with virtually no wear and tear to your spine. In simple economics terms, the elbow plank would be a far more viable choice for the consumer.
Another aspect to consider is directional load to the spine. If we consider that most of us are sitting for far too many hours of the day, then the general trend is that our lower backs are predominantly in flexion. In other words the natural curve of your spine is forced to flatten due to poor sitting posture, in most cases the chair/couch is not ergonomic (for example, airplane seats). The natural curve (Lordosis) of the lower back (lumbar spine) is compromised in sitting (often flattened) (see below image, middle example). This puts huge shearing forces on our lower backs. If you now go and do many sit-ups you are reinforcing this issue by adding even more loaded flexion onto your spine. This only compounds the problem!
It’s better to choose exercises which maintain neutral spine, or counter balance flexion, for example rotational exercises, spinal and hip extension exercises. By choosing counter balancing exercises, there is a chance to “undo” some of the ravaging damage of prolonged sitting. Here are a few good examples:
Lastly, diet – meaning good nutrition and hydration – are also important factors when trying to reshape the body and see stomach muscle definition. Some experts advocate 80% diet 20% exercise as their ratio for achieving results in body reshaping and toning. Rather than wasting your time doing sit-ups, make a few simple diet changes and add some core stability exercises, you’ll look taller and slimmer and your back will thank you for it.
In conclusion, why choose a redundant exercise when there are hundreds of far better ones out there for you? Sit-ups aren’t “bad” they are just very, very outdated. Unless you need to do them because you perform in the circus or the army, remember they’re not really appropriate for the general population. The longevity of your spine is more important. You’re better than that.
Written by Lauren Sale – fitness director PilatesByLauren.com