This is an excerpt from Breathing for Peak Performance by Eric Franklin.
Stretching Your Diaphragm
The diaphragm needs its own designated stretching and strengthening routine, just like any other muscle. The diaphragm moves downward when you inhale, expanding the lungs and creating a vacuum. This vacuum causes air to rush into the lungs and oxygen to transfer through the thin walls of the lungs into the bloodstream. (For more information on the lungs, see chapter 2.)
What makes the diaphragm move downward? The diaphragm is a muscle, and muscles can shorten and lengthen between the origin and the insertion of the muscle. The origin is considered the fixed point, while the insertion is the part that is moved by the muscle.
If you want to stretch the diaphragm, you need to increase the distance between the origin and insertion, as in the following exercise. This exercise stretches other muscles, such as the intercostals (between the ribs) and the oblique abdominals, which in turn increases the benefit for the diaphragm.
- Stand in a comfortable position. You will begin by stretching the left side of the diaphragm. These fibers are mostly located between the 12th rib and the central tendon along the inside of the rib cage, which is called the zone of opposition. Lift your left arm over your head, and place your right hand on your lower ribs on the left side (figure 1.8).