Return to article: The Core Of The Matter
"Core training". Now there is a buzz phrase in the fitness and medical worlds these days. Apparently, everyone's got a core strength issue. You have a sore back? Must be caused by your weak core. Lousy golf game? Make your core stronger. Pain with sitting? Must be your weak abdominals. If you're involved with an active population - you've heard it a thousand times. Now you're hearing it with the sedentary population. Before long, core strengthening will be introduced as a solution to heart disease, stroke, and world hunger.



Well, maybe not heart disease - but I digress.



I have to always step back and put on my "mechanical" glasses to view this topic - and when you go back to the basics of biomechanics, it's amazing what you find.



Is there a value to starting any movement or activity with a solid base of support? Yes. Is it the panacea for all things orthopaedic? No.



If I want to learn a sport activity, or any activity for that matter, I need to be able to recruit the muscles necessary - volitionally - and then use them in a sequence or pattern that is appropriate. As I do so, the muscles in question will naturally respond and adapt to the imposed demands of the activity. In all of this, my central nervous system is the primary driving force - if I can't recruit muscle fibers AND recruit them in the appropriate sequence, then I am not going to be able to do the activity correctly. That being the case, either I am going to get very good at doing a movement poorly - or I will risk tissue overload if (and only if) I do "too much, too soon" and then subsequently ignore my body's feedback mechanisms (pain etc). The same is true of maintaining postures such as sitting.



Along with the central nervous system, muscles respond by adapting to the demands of the activity. Yes, I can strengthen them, but if I don't know how or when to use them, it will be a moot point.



Stuart McGill, a leading biomechanist and spine researcher at the University of Waterloo, notes that "for most tasks of daily living, very modest levels of abdominal wall co-contraction (activation of about 10% of MVC or even less) is sufficient" (2004). MVC refers to the maximal voluntary contraction of the muscle - and thus, 10% would not seem to be a very high value. McGill consistently refers to the "motor control system" as a primary element in spine performance.



So does everyone have a weak core? If 10% maximal voluntary contraction is sufficient for most activities of daily living, I would say the answer is "no". If the average sedentary person exposes him/herself to higher loads through more (and frequent) strenuous activities or sustained loads (i.e. sitting posture), then there may be a deficit - but is "strengthening the core" enough to resolve this? Again, the answer would be no - because the whole motor system is responsible. Is "having a strong core" enough to keep someone injury-free? Again, the answer is no - because the body will still be exposed to repetitive and/or sustained loading which may in fact be causative of the pain.



Having said that, let's look at what most "core programs" have to offer. Take a look at what's available in your community. Ask the instructors what types of exercises they do. I am prepared to bet that most will involve a lot of abdominal work.



Most activities require us to be in an upright or erect posture - be it sitting, walking, or running. If you're bending forward, you're still using the muscles of your back to help raise and lower yourself. So why all the emphasis on strengthening the abdominals? Especially when most variants of abdominal strengthening exercises create extremely high intra-discal and intra-abdominal pressures? If we ARE going to maintain our beliefs in the value of core strength, then the abdominals are not the exclusive solution, perhaps not even the primary point of emphasis. It's a coordinated effort between central nervous system, abdominals, and extensors - dependent upon the individual's required function.



As I am always known to say - it's another example of "form follows function" - in which the form of the body reflects the demands imposed upon it functionally.



But doesn't having stronger muscles help me sit up straight? Not unless you use your brain (again, volitional control) to make those muscles contract. What does this mean? You can't just be strong - you have to actively use those muscles under your own control - meaning that you have to "think" about sitting up straight before any amount of exercise will help!



Is there a place for having a strong core? Absolutely. Being able to translate rotational stresses from upper to lower body - for example, with running or golfing - is definitely of value. But core strength in these activities needs to be in positions that are functional for the participant - in which they learn to "groove" the motor control system within components of their sport activity - and this typically won't involve lying down. Yes, you'd want to work on components - but within the scope of the whole movement pattern.



If we continue to go back to sound training principles, intelligent and progressive application of loading, and simply listening to what the body gives us as feedback, we will continue to progress safely and efficiently. Unfortunately, "core strength" has become more of a buzz phrase than actually getting down to good sensible practices. It's become an all-encompassing excuse for just about everything. The beauty is that it provides a moving target that everyone and anyone (practitioner, coach, and trainer) can address forever and ever, regardless of the cause and effect nature of the onset of symptoms - or the resolution of the same. If we live in fear of "not having a strong enough core" we are effectively handcuffed. Training principles are well understood - and the responses to loading are as well. In order to live well on the planet - or to perform at a higher level - we simply need to apply the science and get down to the core of the matter.

I sent this article to the boys and since they read it they've stopped doing those crazy crunches. I feel so powerful! And, they asked me to ask "that guy" pointing to your poster on the wall, if their disks are really gonna wear out. And one of my more vain gym buddies said "isn't beauty now worth the spine pain later?" So, is the 6-pack craving guy really gonna damage his disks?

Posted Wednesday, June 03, 2009 9:13 AM
Stop Doing Sit-Ups: Why Crunches Don't Work
Kate Dailey
Everyone knows that the road to flat, tight abs is paved with crunches. Lots and lots and lots of excruciating crunches. Or is it?

As it turns out, the exercises synonymous with strong, attractive abs may not be the best way to train your core—and may be doing damage to your back.

“We stopped teaching people to do crunches a long, long time ago,” says Dr. Richard Guyer, president of the Texas Back Institute. That’s because the “full flex” movement—the actual “crunch” part of crunches – puts an unhealthy strain on your back at its weakest point. The section with the most nerves (and most potential for nerve damage) is in the back of the spine, which is the very part that bends and strains during a sit-up.

“There are only so many bends or a ‘fatigue life’,” in your spinal disks,” says Stuart M. McGill, a professor of spine biomechanics at the University of Waterloo. Inside each disk is a mucus-like nucleus, he says, and “if you keep flexing your spine and bending the disk over and over again, that nucleus slowly breaches the layers and causes a disk bulge, or a disk herniation.” A herniated disk won’t show through your swimsuit, but it’s no fun, and can cause persistent back and leg pain, weakness, and tingling.

Think of the oft-repeated advice for movers: bend at the hips and lift with your legs, not your back. And what is a sit-up but a back bend done in a lying position? “When people are doing curl up over gym balls and sit-ups, and this kind of thing, they are replicating a very potent injury mechanism on their back,” says McGill. “Every time they bend it they are one repetition closer to damaging the disk.”

And of course, when people do crunches, they rarely stop at one or two: in the quest for flat abs, they’ll churn out dozens at a time, bringing them ever closer to “flex intolerance”—so much pain and stiffness that it’s difficult to tie one’s shoes or bend down to pick a penny off the ground.

But who cares about back health as bathing suit season approaches? Turns out, crunches might not be the best solution for a flat stomach, either. That’s because doing too many sit-ups at the expense of other, more comprehensive movements can lead to the dreaded “aerobic abs.” That’s the term celebrity trainer Steve Maresca coined to describe the distended stomachs of those who focus only on the rectus abdominus muscles targeted by sit-ups and crunches. “They look great from the front, but when they turn to the side, their stomachs are extended,” he says. To get the long, lean look, one needs to work transverse abdominius, a large muscle that holds in those rectus abs, and is mainly unchallenged by traditional ab work (aka, the sit-up and crunches).

Doing a sit-up doesn’t train your ab muscles to do the job for which they were designed – keeping your spine straight and secure and providing power for your movements. In everyday life, “the abdominals are braces,” says McGill, author of "Ultimate Back Fitness and Performance" (Stuart McGill, 2004). When doing any athletic movement—even opening a door—“the spine is in a neutral posture, not flexed, and the abdominal muscles are contracted to brace the spine.”

The best way—for both your back and your beach body—to work your midsection is to do movements that challenge the muscles to perform the way they're designed and expected to work in real life, and not to train muscles in isolation. “It’s important to have strong abs, but strong abdominals are not the only thing,” says Dr. Guyer. “You have your back extenders, your flexors, which are belly muscles, you have your oblique muscles.” Working all of these muscle groups—the anatomical association known as “the core”—is essential to both back health and general athleticism.

As a result, only training for good-looking abs won’t add to your athleticism or overall strength. On the other hand, moves not traditionally designed for good-looking abs can in fact help strengthen and tone those muscles.

Consider the pushup. Not usually thought of as a great ab move, the pushup forces you to work several muscles at once: it forces your core muscles to stabilize your trunk as your arms and back work to move the body up and down. “Do you see how a pushup is a full body challenge?” says McGill. “It challenges abdominals, front of your legs, your arms and your back. That is how you use those muscles in real life.”

Like the pushup, the best exercises for back health and a firmer stomach are ones that work your abs while holding your spine straight, like planks or leg drops (done when you lie flat on your back, with your hands at the base of your spine for added support. Raise your legs up at a 90 degree angle, then slowly lower until they’re only inches from the ground. Repeat until your stomach burns and you want to throw up). And because your core is the center of power for most other exercises, a long workout full of dynamic movements targeting legs, arms and back also translates to a good core workout. (For more examples of effective ab exercises, visit McGill’s site, backfitpro.com.)

Of course, it won’t matter how muscular your torso is if your body fat is too high. The best way to build strong, visible abs isn’t through repeated sit-ups, but by engaging in circuit training that has you working your entire core while you’re burning calories – and to keep yourself disciplined during meals. “If you want to burn your fat mass, make sure you have a combination of weight training and cardiovascular, but 90 percent of good abs is your nutrition,” says Maresca. However, he does offer a quick tip for those of us with a weakness for caloric food: standing up straight and pulling back your shoulders will instantly tighten your transverse abdominal muscle, making you look a little leaner. It’s not quite as impressive as showcasing a well-developed core via 10 percent body fat, but it does leave a lot more time and flexibility for hitting up happy hour.