What are side stitches?

Side stitches, also known as side cramps, are a common discomfort experienced during activities like running, swimming, or biking. According to Andrew Huberman, these are not actual muscle cramps but rather a phenomenon related to the phrenic nerve. The phrenic nerve, which controls the diaphragm for breathing, has branches that connect to other areas such as the liver. Disruption in the normal breathing patterns during physical activities can cause what's known as referenced pain from these nerve branches, which is commonly experienced as a side stitch.

The way to alleviate a side stitch is quite simple and involves a breathing technique described by Dr. Huberman as the "physiological sigh." This method consists of a double inhale through the nose followed by a long exhale, and repeating this two or three times can help relieve the discomfort by adjusting the firing patterns of the phrenic nerve 1 2.