three muscle groups to the abdominals.
The first of these is the rectus
abdominis, the wall of muscle that
covers the front of the abdomen
and gives your abs a washboard appearance.
The rectus abdominis helps flex
your torso forward at the waist.
When it contracts, it pulls your
hips toward your shoulders.
second important muscle group is
the obliques at the sides of the
hips. This group is usually called
the external obliques, although
there are really three layers of
muscle, including the external,
internal, and transverse oblique
muscles. The obliques contract to
bend your torso to the side and
help you twist your torso in relation
to your hips.
final muscle group is the intercostals,
which run diagonally across your
sides above the obliques. Your intercostals
run from the top of your obliques
up to the serratus muscles of your
chest, and they contract to help
flex your body at the waist and
twist your torso in relation to
your hips and legs.
Crunches, and Ab Exercises can be
done in many different ways using
various types of equipment. Below
is just one of the many ways to
exercise your abdominals.
Machine crunches allow for a convenient
method of adding resistance, in
the form of weight plates, to the
exercise. As in crunches, the upper
abs are stressed, but even more
than with body weight alone.
Position: Sit on the
seat and adjust according to your
body. Hook your feet under the bar
pads if appropriate, depending on
the machine. Reach back and grasp
the handles of the machine. Put
your chin to your chest at the starting
point of the movement.
Performance: You must
do four things at once to perform
crunches. Force your shoulders toward
your hips. Use lower abdominal strength
to pull your hips toward your shoulders.
Use your upper abdominals to pull
your shoulders toward your hips.
Forcefully blow air out of your
you perform these four tasks, you
will feel a very powerful contraction
in your front abdominal wall. Hold
this contraction for a brief moment,
return to the starting position
and repeat the exercise.