When Crunches are a Mistake
Updated: Jan 2, 2020
I often use the abdominal gold standard, THE CRUNCH, as a first step in core strengthening. It’s been well rehearsed, it usually elicits the strongest contraction and everybody knows how at least attempt one. But there are times when crunches should be downgraded on your priority list. Read on to see the when & why, some you've heard & a few you haven't:
1- No Crunches during pregnancy:
Obvious I hope, but to spell it out, as the baby grows, the mother's torso needs her abdominal muscles & connective tissue to stretch in order to accommodate the increase in abdominal size. To accomplish this, the 6-pack abdominal muscle stretches from one unit into two separate 3-packs, making it virtually ineffective for flexing. If you continue to flex into a crunch, the separation could spread, causing what's known as diastasis recti, and hernias can develop through that widened connective tissue. Once this occurs, rehab and/or surgery is required to return the 6 pack position and muscle tone to an effective length/tension relationship.
Since I have you thinking about pregnancy abs, there is another possible cause of diastasis recti (the 6 pack separation that does not go away) that I have yet to see explained- a diastasis caused by aggressive abdominal bracing. Ideally in pregnancy, you should get a normal amount of stretch between each 3 pack as well as some stretch of your abdominal corset muscle, the transverse abdominis, which is used in bracing. Light bracing is actually a recommended exercise during pregnancy, bringing about awareness to the muscle that will help you return to normal after childbirth. But excessive bracing (through intention or excessive effort needed for certain exercises) may maintain/increase transverse abdominis tone, allowing the body to only stretch in its most flexible area, again the diastasis recti. Sometimes herniations are even seen within the muscle fibers of the rectus or transverse abdominals if the abdominals are unable to stretch adequately. Just an fyi- relax the abdominals during pregnancy- that is the healthiest thing you could do.
2- No Crunches for a LONG while after pregnancy (probably about a year):
This doesn’t mean you shouldn’t work on your abdominals. It just means the rectus is the last muscle you should try to selectively strengthen bc of it’s length-tension compromise: it’s stretched length-wise after pregnancy, making it extremely difficult to find enough tension to elicit a strong contraction. If you try to use it, you can easily set yourself up for pusher syndromes (see below.) In addition, many women have 6-pack separations, aka diastasis recti, and contracting the rectus 6-pack when it's not in optimal position can make the separation worse.
This is the time for transverse abdominal strengthening. It helps to already have some body awareness of how this muscle feels to contract, which is best done before or during pregnancy. However, all is not lost if you haven't tried it before. It's best started with a strong exhale, you should feel the front/side of your torso tighten and you should see your stomach get smaller as you contract. I usually start women on their back with knees bent, but quickly have them try the transverse abdominal contraction in sidelying and on all fours as well. They can be done immediately after vaginal childbirth or once the incision has healed after C-section births.
Once the transverse abdominal increases its resting tone, your torso will begin to return to its normal size and bracing capabilities, and you can progress abdominal strengthening to include the rectus and the obliques without causing pain or dysfunction.
3- Osteoporosis w obvious signs of wedge fractures:
The weakened bone strength of Osteoporosis creates wedge like fractures that form the kyphosis (rounding) of the upper back. This tell-tale sign of the Osteoporosis sets in motion other biomechanical complaints- limited shoulder mobility because of altered shoulder blade placement, and pressure on the abdominals causing some protrusion there (moving left to right in the picture.) Many clients with this condition know they should work on their posture and are tempted to include crunches for their abdominals. I often advise against this strategy and choose to work on posture and abdominals another ways.
Trunk flexion may further fracture the weakened spine by exerting a force in the same flexed position that created previous wedge fractures. Repeated flexion can also aggravate kyphotic symptoms by teaching the only way to contract the abdominals is through rounding the upper back- the exact position you are trying to counteract when upright.
There are multiple ways to increase tone and stability in the core without intentionally repeating the slumped forward position. While upper body weakness may make plank varieties difficult to perform in older adults, there are multiple modifications that can be utilized for reduced weight bearing tolerance. Leaning on a counter or bed are some ways to lessen the weight bearing load while mimicking the position that can improve posture. Spending time on all fours, or on one elbow & one hand can also lessen weight bearing difficulty for those who are more active but still have limited weight bearing tolerance.
In addition to weight bearing training, resistance exercise of the upper back & shoulder blades can improve the natural alignment of the torso & prevent further falling forward of the upper trunk when standing. While this does not effect the abdominals directly, it can pull the abs into an optimal length-tension relationship through upward stretch (moving backwards from right to left in the picture.)
4- With acid reflux syndromes:
Regardless of the initial cause, flexing the trunk exacerbates symptoms by squeezing the stomach contents, increasing the likelihood of stomach acid squeezing into the esophagus. Best not to do. And just as in the case of osteoporosis, repeated flexion may influence slumping when seated or standing, exacerbating symptoms in these positions as well.
Better positions to try for abdominal strengthening are on all fours or in planks, along with upper back strengthening just as in Osteoporosis programs. If symptoms are really painful, abdominals may need to be discontinued completely until symptoms subside. Upper back, arm and leg strengthening are most often able to be continued without issue.
5- In Pusher-Syndrome dysfunctions:
People with excessively stretched and weak abdominals often rely on breath holding (valsalva) & “pushing down” in order to find muscle tension there. While using valsalva is correct in certain situations, it is a maladaptive strategy if it's the only way known to elicit abdominal tension. Prolonged outward pressure stretches the abdominals further & can often lead to pelvic prolapse & hernias. Adding a crunch to vasalva is like rolling up a toothpaste tube without the cap on- things will unintentionally be pressed out.
Unfortunately, most people with a pusher dysfunction can ONLY feel their abdominals in a crunch with full valsalva pressure. They may attempt plank varieties but only feel effort or pain in their arms or low back, but nothing in their abdominals. In these cases, extremely patient abdominal & breath work is needed in multiple positions. While they can perform most abdominal exercises, the intention should be quality not difficulty, and breaks given when valsalva returns. Crunches can be used, but only to work backwards from- first learning how to exhale while contracting the abdominals, then how to position the ribs down without needing to crunch. Once these components are learned, alternate positions can be incorporated, using the same techniques of exhalation & rib position when abdominal contraction is needed.
Posture training is Core strength training:
During & after pregnancy, with osteoporosis & with acid reflux symptoms, and when noticing the effects of a pusher-syndrome are all times when posture training is paramount to healthy and pain-free living. While the abdominals are generally most easily found with a crunch, there are more effective (and safer) ways to combat the negative postural effects brought on by these conditions.
Learning how to:
1- Limit valsalva with breath training,
2- Brace the stomach while making it smaller, and
3- Contract the abs in order to stop/limit back extension
are three avenues to explore in order to regain postural support and return normal dynamic tone to the abdominals. It's often difficult to believe learning theses "exercises" can be effective since they don't feel hard enough to provide fast results. But you will be surprised at how much improvement they can actually provide. They are the sweet spot for an effective core strengthening plan when looking to return tone to stretched abdominals.