Death to Crunching
by Scott Abel
Some time ago, I saw a news report about a guy who'd set
some kind of world record for sit-ups. I'll admit he was
impressive; he could do thousands. And yet, the guy had no visible
abdominal development. Not even a cosmetic outline.
If the purpose of sit-ups is to train abdominal muscles, why
wouldn't the world-record holder have some signs of ab
development? The answer is simple: He'd trained his body to
perform an exercise. He wasn't training his muscles at all.
Traditional ab training is based on the idea that the muscles
function by bringing your pelvis closer to your rib cage. According
to that simplistic view of biomechanics, any movements that
accomplish this, like sit-ups and leg raises and all their
variations, also accomplish your goal of training your
abs.
But, as I said, they don't.
They also fail to give you all the other things you're
looking for when you work your abs: a narrow waist, a pain-free
lower back, and a stronger body in general.
How to accomplish all that, if traditional ab training
doesn't do the trick? Sports offer a clue.
Athletic Supporters
I'll say this up front: You can't look at someone with
an exceptional body or body part and assume that you can achieve
the same results by mimicking his workouts. Setting aside the issue
of genetics — you can't train a powerlifter to look like
a runner, just as you can't train a runner to look like a
powerlifter — there's far too much individual variation in
the way we respond to the workouts we do.
We can, though, look at
systems of training and draw some
conclusions about adaptive responses.
Let's start with gymnasts and acrobats. To the best of my
knowledge, few of them do any formal abdominal training, yet any
one of them has abs bodybuilders should envy — all the
muscular development without blocky obliques or a bulging rectus
abdominis. I don't think it's a coincidence that they
also have perfect glute development.
Of course elite gymnasts and acrobats are genetically
predisposed to be good at those activities. The ones you see in the
Olympics or at Cirque du Soleil are selected early in life and
train hard for hours a day.
But that doesn't mean we can't learn important lessons
from their training systems, particularly when we contrast them
with the traditional approach to ab exercise. Specifically, they
use their mid-body muscles for three purposes, all of which are
related to the overall goal of strength transfer.
Coordination
I don't think I need to explain why this is important to an
athlete.
Range of motion
This works both ways — you can hurt yourself with too
little or too much range of motion.
Muscle contraction
Different types of muscle contractions help you stabilize your
body, create force, resist force, overcome force, accelerate, and
decelerate. In bodybuilding we tend to focus on
producing force, but in sports it's just as important to be able to
reduce force, or at least transfer that force. No matter
what sport we're talking about, we assume that we generate
power from the ground, but we
express it through the muscles
in the middle of the body.
Core Competency
The phrase "core training" gets used often enough
these days, but there's no one definition of what that means.
Some experts assert that "all training is core training."
While partially true, it's also misleading. At the other
extreme, bodybuilders tend to think of abs as a separate entity, a
"body part," which is equally misguided.
I like to talk about "the core" as a box, with the abs
in front, the paraspinals and glutes in the rear, the diaphragm on
top, and the hip girdle and pelvic floor on the bottom. Within the
box are 29 pairs of muscles that help stabilize the spine, pelvis,
and movement chain during every type of movement.
Inside the box: side view of the core
muscles.
One key to understanding how the core works is to resist
thinking of muscle actions in terms of straight lines. Most
movement patterns are diagonal or rotational. That's why
muscles, joints, and bones are connected in diagonal and spiral
patterns.
I agree with Vern Gambetta when he says this: "Athletes who
move in many directions, and have to control their limbs in a
variety of positions, have ripped abdominals as a result of
movements they perform, as opposed to isolated
work."
So how do we adapt that into a training program? Bodybuilders
aren't gymnasts, so we have to forget about exercises that
demand profound coordination or talent. There'd be too long a
learning curve. We can get there faster by creating two types of
exercises that challenge you without forcing you to enroll in
circus camp:
• Static exercises, in which you have to control your limbs in
space in a variety of movement planes and ranges of motion. An
example would be a plank exercise in which you raise one leg and
hold it out to the side.
• Movement-based exercises, which force muscles to work together
in multiple planes of motion and with various degrees of rotation.
An example would be standing wood chop-type exercises using a
medicine ball. You can chop in vertical or horizontal patterns, or
any diagonal pattern in between.
A Quick Word about Hip Flexors
I've left open the question of why sit-ups and crunches
aren't good exercises for abdominal muscles. After all, even
if they aren't the best exercises, they still do the trick,
right? Not really. The problem comes from what we call the
"psoas paradox." The psoas major is a hip-flexor muscle,
meaning it acts to pull your thigh bone up toward your torso. In
conjunction with two other hip flexors — the iliacus and the
rectus femoris (part of the quadriceps group) — it can take
on most of the work in traditional ab exercises. This was likely
the case with our world-record holder in sit-ups, who showed little
to no abs development.
A study published in 1965 showed that most people use two of
those muscles, the rectus femoris and iliacus, to initiate a
sit-up. A study published in 1994 showed that the psoas and iliacus
are most involved in the exercise after about 30 degrees of hip
flexion. Between those two points, there's not a lot of room
for the abdominals to take over as prime movers.
That's why we have the crunch. By shortening the range of
motion of the traditional sit-up, it takes much of the hip-flexor
involvement out of the movement. But that's all you're
doing with the crunch. You aren't burning many calories, and
there's hardly any functional benefit to working muscles
through such a such range.
Accueil 
