Are crunches an effective exercise for building the abs?

Question

Vince Gironda was famous for training people like Arnold and Lou Ferrigno and operating Vince's Gym. He was one of the OGs of professional bodybuilding.

There's a story I've heard more than once about a man doing crunches at Vince's gym. Apparently, Vince refunded his money, told him to get his stuff, and kicked him out of his gym, saying something like, "nobody does crunches in my gym!"

Why would Vince be so anti-crunch? Is there any merit to this belief? Are crunches an effective ab exercise for bodybuilding?

Answer 1

Rippetoe & Kilgore describe in Practical Programming why many trainers--particularly strength trainers, and most particularly weightlifting trainers--eschew crunches:

The lower back is supported from the anterior by the abs, and ab work done correctly, protects and assists lumbar stability. "Done correctly" means that the abs are strength-trained, as opposed to endurance-trained with high reps and low resistance. Weighted sit-ups or some version of them, knees-to-elbows from a hanging position on the chin-up bar, and exercises that isometrically load the abdominals in a fashion similar to their normal postural-support function, are preferred over exercises (e.g., crunches) that do not adequately stress the muscles in a way that actually applies to their role as spinal supporters.

From page 102. The position that the function of the abdominals is not solely to curl the torso forward and in, but rather primarily to provide isometric contraction for postural support, is the key. Many people note that the abdominals are quite necessary for bracing the torso during heavy lifting, for example, pulling movements deadlifts, cleans, and snatches, as well as squats and overhead work like presses and jerks.

There are many supporting reasons: crunches provide very little resistance, they often dovetail into a mistaken belief in spot reduction, or their use signals a misguided priority of developing a six-pack without attention to fundamental strength, conditioning, and mobility. However those reasons are secondary to the central claim that the abdominals are primarily useful for bracing the trunk to resist movement (whether under a barbell or to maintain good posture during normal daily activities), rather than flexing the torso in order to move a load.

Answer 2

Why would Vince be so anti-crunch?

I wouldn't say Vince is anti-crunch so much as he is anti-novice. The distinction here is that Vince would assume if someone were to do crunches as part of their routine, then that person is a novice and does not belong in his gym.

Is there any merit to this belief?

Yes. Ask anyone in the world and chances are most people will only know of the sit-up and crunch. But instead ask any intermediate or advanced bodybuilder, and they are likely to tell you that they haven't done crunches in years. Why the disparity? Because there are hundreds of exercises at peoples disposal for doing abdominal work that are both safer and more efficient than crunches, but chances are the novice will only know of the crunch.

Are crunches an effective ab exercise for bodybuilding?

A great deal of exercises can be effective for building muscle, but that doesn't mean they're optimal or even safe. Sure you could use crunches to build up your abs, but that would be like eating a McDonalds burger when you have a cut of prime rib already on your plate.

Answer 3

Crunches CAN be an effective tool, however there comes a point where they do more toning and conditioning than they do size building.

The function of the abdominals is to curl the torso "forward" and "in" (These are subjective to the position that you start in). If you take your lower ribcage and try to picture touching that to your hips, causing your upper body to kind of curl into a ball, that is the motion that works the abdominals.

If most of the motion is occurring at your hip joints and your back is relatively straight, then you are working your hip flexors rather than your abdominals as the primary mover.

Now, if your abs are underdeveloped, then crunches will definitely work the abs. However, once you get them to a base level of conditioning, then you don't really get much more out of doing more crunches. It's kind of like being able to bench 250, so you don't get much out of doing bunches of presses at 135.

Now if you add weight, vary the exercise (Such as hanging crunches), then you can get back to the building, but you are going to need to keep increasing the stress on the muscle to see advancement in size.

Addendum - As with almost every muscle group in the body, there are a group of antagonistic (opposing) muscles, and these are the muscles of the lower back (erector spinae, etc.). For all the work that you do on your abdominal area, you need to match that with work on the lower back. Imbalances between these two are often a cause of lower back pain, and can also promote poor form, injury and other like complications. Any time you work one muscle group, you need to make sure to have equal work on the opposing muscle group(s).