To Curl or Not to Curl? That is the Question.

Traditional exercise offers us several manifestations of the sit-up.  Crunches, curls,– you name it and I’ve done it.  Every other week it seems like there’s a new infomercial advertising some contraption that is supposed to assist and enhance your abdominal curl.  Despite the hype, it is very challenging to do a curl correctly.  Most people rely too heavily on momentum to draw their chest to their knees, and have trouble curling from their center so they end up using their neck to compensate.  Ever since I began exercising with a trainer, this is the way I have been taught to strengthen my core. 

Flash forward to the future: I now know that abdominal curls mainly train our rectus abdominus, or six pack muscles, without any peripheral benefits.  Clients are often surprised when I tell them the six pack muscles are actually the most superficial layer of your abdominals and they do not even attach to your spine.  Somehow along the way, we equated ab curls with strength and support for the back, but in actuality just because someone has a six pack doesn’t mean they aren’t vulnerable to throwing their back out.

Let’s attempt to define your core.  It’s the centre of your body and it extends all the way from your shoulders to your hips.  Core strength is made up of all the muscles in your trunk including your back, chest, abdominals and hips.  A strong core prevents back pain, improves posture, enhances breathing and increases performance moving from the inside out. Optimal movement should originate from your core and extend outwards to your arms and legs.

Core muscles that contribute to spinal stability:

Internal and External Obliques

  • You might already be familiar with these muscles that help to whittle down your waistline and create that sought after shapely hourglass figure.  This pair of muscles cross diagonally over your midsection, like an “X” of support and allow your trunk to side bend and rotate.


  • Pronounced (so-as), the psoas is the only muscle in the body that connects your spine to your legs.  We can’t see it or flex it like we can our bicep, but we know it’s involved in connecting the core to your lower body.  It attaches the bottom of our thoracic spine (mid-back) to our low back and runs through our pelvis to the front of our hip joint, attaching to the top of our femur (thigh bone).  Traditionally considered a hip flexor, (which means it can brings your trunk and legs closer together), the psoas is a major part of stabilizing the spine by the very virtue of it’s location.  A tight psoas pulls on your lumbar spine, which places excessive stress in the lower back, causing low back pain.

Finding stability in your core also involves the “deep core” muscles.  These muscles give integrity to your body from its deepest layer:

Pelvic Floor

  • Also known as your “kegel muscles,” the pelvic floor helps to stabilize the pelvis, and support the organs of the lower abdominal cavity, like the bladder and uterus.  Woman who’ve had a baby know how important these muscles are.


  • These are a series of muscles that attach to the spinal column from your sacrum all the way up to your neck.  The muscles stiffness and stability make each vertebra work more effectively, reducing degeneration of the joint structures and allowing our body weight to be evenly distributed along the spine.


  • Breathing is integral to activating your core.  Correct breathing allows the diaphragm to utilize respiratory function and create intra-abdominal pressure protecting the spine before you exert force.

Transverse Abdominis

  • It is the deepest layer of abdominal muscles and runs between the ribs and the pelvis, horizontally from front to back. When activated, these muscles create a deep natural “corset” around the internal organs and lumbar spine helping the spine to stabilize during movements that involve the arms and legs.

If you are aware of changes in your spine or carry an extra load (for example if you are pregnant or have osteopenia, osteoporosis, spinal stenosis, or a bulging or herniated disc), err on the conservative side to protect your spine.  I recommend avoiding doing any kind of flexion in your spine (rounding forward).  Always consult with your Doctor before taking on any new exercise regime.

Try trading in your abdominal curl for the bird dog, side bridge and stirring the pot.  Dr. Stuart McGill, professor of spine biomechanics at the University of Waterloo in Canada, demonstrates a few core exercises that emphasize all the major muscles that support the spine.  This video debunks some core myths and offers some valuable alternatives to the ab curl.  These exercises work your core safely and efficiently while conserving your spine.