Gabe Mirkin, M.D.
It took years for the medical community to finally learn
what causes a side stitch. Suddenly a runner develops pain in
the right upper part of the belly, just underneath the ribs in the
front. With each step the pain worsens. Doctors proposed all
sorts of explanations for side stitch and most were nonsense. A
stitch is not caused by gas in the colon because it is not relived
by passing gas. It is not caused by a liver swollen with blood
during running, because the liver has a very distensible capsule
and does not enlarge much during exercise. It is not caused by
cramps in the belly muscles because the belly muscles are not
held rigidly when you have a side stitch, and it does not hurt
when you push on the belly muscles. Lack of oxygen to the
diaphragm doesn't cause them because blood flow to the
diaphragm is not shut off by running. They are not caused by
trapped gas in the lungs because gas does not get trapped in the
lungs during exercise.
The first reasonable explanation and successful
treatment came from Dr. Tim Noakes. Thick fibrous bands called
ligaments extend downward from your diaphragm to hold your
liver in place. When you run, your liver drops at the exact time
that your diaphragm goes up, stretching the ligaments and
causing pain. Humans have a fixed pattern of breathing when
they run. They have a two to one breathing ratio, breathing
once for each two strides. Most people breathe out when the
right foot strikes the ground. When you breathe out, your
diaphragm goes up, and at the same time, the force of your foot
strike causes your liver to go down. This stretches the ligaments
that attach the liver to your diaphragm, causing pain. So the
cause of a side stitch during hard running is a stretching of the
ligaments that hold the liver to the diaphragm and the cure is to
relieve the stretching of the ligaments.
When you get a side stitch, stop running and press your
hand deep into your liver to raise it up against your diaphragm.
At the same time, purse your lips and blow out against the tightly
held lips as hard as you can. Pushing the liver up stops
stretching the ligaments. Breathing out hard empties your lungs.
Usually the pain is relieved immediately and you can resume
running as soon as the pain disappears.