Are crunches/sit ups a functional?

Aren't abs are meant to be stabilizers for the back and not prime movers? If so why are crunches and sit ups part of most functional training programmes?

I know there are functional movements which are similar and are useful in a combat scenario, ie getting up off the floor from your back with little or no help from your hands but you can train for that by actually practising it - but I can't think of many others. I am recovering from a herniated c6/7 disc in Feb this year and am just starting to get back to some normal training. I never had a problem before with my core/abs but posture was my problem. I have learnt from my recovery program about the importance of stabilising the core and not just tensing the mid section when exercising/lifting, and this has helped a lot and feel that my abs haven't lost strength despite not doing one crunch or sit up for about four months. I have done planches, various static holds, torso twist exercises and strikes to the abs, but no sit up or crunches. I will continue to do sit ups just because! - but with less frequency mainly due to effects on my neck but even if my neck was 100% it has got me thinking. Are crunches and sit ups more for cosmetics? What do you think?

The rectus abdominus, which is what i assume you mean when you say "abs," is a prime mover in spinal flexion. Of the exercises you list, the only one in which spinal flexion is a necessary movement is the crunch. Ergo, if you wish to activate the RA as a prime mover, then you need to have spinal flexion.

However, many of the exercises you mention that you have been doing (situps included), activate the RA isometrically, which is why you don't feel as though you've lost strength, since isometrics are a fine way to build or maintain strength, particularly in muscle groups with small ROM's.


the rectus abdominis, even. (courtesy my new nickname, "pedantic as fuck").

But doug... what about them lower abs?????

Haha. That's what i get for posting before breakfast i guess.

You need special exercises for the lower abs Ali, i figured you of all people would know a thing like that.


very special, LOL.

edit -- btw, I spelled rectus abdominis wrong for years, till Mel Siff pitched a fit about it on the Supertraining list. (Not my misspelling, personally, but the fact that "everyone does it"). So now I can act all smug.

"Given that the sit-up imposes such a large compression load on the spine, regardless of the leg being bent or straight, the issue is not which type of sit-up should be recommended. Rather, sit-ups should not be performed at all by most people." -Dr. Stuart McGill

just as a side note, in my limited experience in bjj I have found a lot of use for sit-ups as a functional exercise when on the bottom in the guard.

I hate any form of situps, crunches etc. There are more fun ways to work the core than endless reps of those stupid situps.

RIP Mel Siff...

I know you guys were being facetious regarding lower abs, but Charles Poliquin makes a great point about them, to paraphrase:

"From a neurological standpoint, the abdominal muscles that extend below the belly button are controlled by two nerves that originate from the region of the first lumbar vertebra. So although many anatomy books show the abdominal muscles as a continuous band of single fibers, from a functional and neuroligical standpoint the abs can be classified as having upper and lower segments"

Yeah. I dont even think that anatomy books show the muscle as being
continuous usually, having several segments of attached connective tissue

which give it that bumpy look. I'm fairly certain that there is a feasible
distinction between control over various abdominal regions, but i assume
that concious control is extremely limited.


True HERTSWENIP -- and more from the Supertraining list (so not just Poliquin) about belly dancers and activating different fibers in the abdominal wall sequentially. So there is something to it.

Still, does this make any difference if trying to strengthen the abdominal wall? -- won't hard contractions, or working near failure, take care of firing 'upper and lower segments' ?

Is it in the rectus abdominis that the fibers are recruited sequentially?
When you say "abdominal wall" i wonder if its not other muscles that give
the RA the appearance of being activated sequencially (since i have never
seen anyone make different parts of their RA flex independently).


This seems likely if innervated by different nerves. But again, unless you're just not working it hard at all, does this make any difference for training? (Not talking about belly dancing, where you might have to 'train' to roll your abdominal wall; there it makes a difference, but not to strength training as such).

The obliques are regionally activated but all sections of the rectus are activated together at similar levels during trunk flexion.

T-Nation: You're saying that there's no way to work the lower-abs vs. the upper-abs, which is very contradictory to conventional wisdom. Can you expand on this?

Stuart McGill: To be clear, I'm only talking about the rectus abdominus. There have been several problems in the scientific literature leading to misinterpretation. There's a muscle called pyramidalius, which is a lower muscle that overlays the bottom beads of rectus, but only in some people--it's an optional muscle.

Those using EMG (electromyography) who claim there is an upper and lower rectus might be monitoring pyramidalius, but if you control with calibrated and normalized EMG our work shows that all four beads of rectus pretty much fire together within the noise and randomness of the signal. On the other hand there are absolutely regional differences in the obliques. You need several types of challenges to train all of the neuromuscular compartments of the obliques.


yeah that's what i was getting at in my first post in reference to general
weight lifting. But for the sake of science, i was wondering what your
take, or what was said in supertraining about belly dancing type activities.
I can't help but notice you said "abdominal wall" instead of Rectus

Bear in mind that this is for my own curiosity.


My saying 'abdominal wall' was just random sloppiness.

I think the muscle fibers can be fired sequentially, yes; I think if the muscles is being contracted hard, they're all gonna get fired. To fire in a particular pattern is a bit of a 'trick' that I don't see as functional outside of displays of bellydancing or something similar.

All that was said on the Supertraining list was that the usual info that 'it's all one muscle' is, as HERTSWENIP pointed out, not the whole story. At least, that's what I recall. I could search the archives and see if there was more, but I don't think so.

If Poliquin thinks separating upper and lower from a 'functional standpoint' makes sense, I'd like to know what he means, functionally. If it's just anatomical function, ok; if it there are implications for ab-strengthening, I'd like to know what they are. I'm skeptical that it's worth paying attention to, honestly, but not closed to the idea.

Ok, this isn't the post I was thinking of, but a later one that simplifies a bit. (This is excerpted from a longer post, originally dealing with doing crunches on a Swiss Ball, and pointing out that what is marketed as 'core stabilization' is often really peripheral stabilization... but I digress).


From Mel Siff:

Now, some of you may recall my mentioning the fact that some bellydancers and bodybuilders show that some people can acquire the skill to preferentially
activate certain regions of the abdominals (upper, middle, lower, left and right sides). Some may use this information to state that I consider that one should do different exercises for "lower" and "upper" abs, but that would not be entirely accurate. It is inaccurate because it is impossible or extremely difficult (without plenty of biofeedback practice) to recruit one part of the abs and allow the other parts to remain dormant. Moreover, there is no scientific or practical evidence that more isolated ab region training offers any significant performance or shaping advantages than more general ab training or training with exercises that do not even focus intentionally on the abs (such as squats, standing press, tricep pushdowns and bench press).

If you do "lower ab" exercises, then all other parts of the abdominal muscles (yes, including the obliques) will also become active. Similarly, if you do "upper ab" exercises, then the lower and all other parts of the abs will also become active. If you do any form of natural movement or stabilisation against large or suddenly imposed loads, then the entire abdominal musculature will become involved, with the degree of overflow throughout the abdominal region and to many other adjacent and distant muscles being
determined by the load being handled by the body. Generally, it is a matter of overkill or redundancy to do numerous exercises for the abs, using various
free standing and toy assisted drills. One can enhance abdominal strength and shape by means of a very small inventory of exercises, most of which you
need to experiment with to determine those which best suit you physically and mentally.

"i wonder if its not other muscles that give the RA the appearance of being activated sequencially (since i have never seen anyone make different parts of their RA flex independently)."

Take a gander at some of the pics on this site from an old muscle control course.

Or this one gives a closer view.

Certainly looks like voluntary control of the RA to my untutored eye. :)