You've probably encountered a situation when intense running caused a stabbing pain in the side under the rib cage. It can be so strong that it makes you stop and stop any movement. In medicine, this pain even has a special name – “exercise-associated transient abdominal pain” (ETAP). But the most surprising thing is that it is still unknown exactly what causes it. There are several theories on this matter. But, in any case, even though the pain is very unpleasant, it is not life-threatening.
While running, many people experience severe pain in their side. Photo source: www.tennis.uz
Why does my side hurt when running
The ETAP explanation was first proposed in 1941. Scientists and sports doctors then suggested that colic was associated with insufficient blood flow to the diaphragm, that is, the large muscle that causes the lungs to draw in and release air. A lack of blood can cause a cramp or spasm accompanied by pain. Why does this occur specifically during running and other intense sports? Because at this moment the blood concentrates in the muscles of the limbs.
Over time, this theory has lost its relevance. The reason is that during sports, the diaphragm also begins to work more actively, that is, blood flows to it in the same way as to the muscles of the limbs.
Pain in the side can occur even while swimming. Photo source: redbull.com
According to another version, due to running, the human body is subjected to constant strong shaking. The result is severe stress on the ligaments that attach the abdominal organs to the diaphragm. True, it cannot be called ideal either. It may explain why runners suffer from side pain, but it does not explain the same pain that occurs in swimmers, for example. You may also experience this pain while rowing or cycling.
Running can cause not only pain, but also a pleasant sensation, which is commonly called “runner's high.”
There are also other versions. For example, one of them suggests that the pain comes from the intestines, since during exercise it experiences a lack of blood flow. According to another version, the pain is caused by compression of the nerves that branch from the spinal cord and pass between the ribs.
But recently, most scientists and doctors adhere to a different version. In their opinion, the cause of pain in the side is the peritoneum. It is a two-layer “bag” that covers the abdominal organs. The inner layer of the abdominal cavity supports the organs, and the outer layer is adjacent to the pelvis and abdominal walls.
Most likely, pain in the side occurs due to the peritoneum. Image source: ppt-online.org
According to a study conducted back in 2000, the most likely cause of pain is friction of the layers of the peritoneum against each other. Because of this, irritation occurs, which causes characteristic pain.
How to avoid pain in the side
There is an opinion that pain in the side during sports occurs most often and most severely in people who have poor physical fitness. However, in reality this is not entirely true. Even highly qualified athletes who constantly train experience severe side pain.
In fact, a person is less likely to experience pain if they do not eat a lot of water or drink a lot of fluids before exercising. This fact supports the theory that pain originates in the peritoneum. When a person's stomach is full, it puts pressure on this membrane, resulting in increased friction between its layers.
You should not drink a lot of liquid during training. Photo source: vimo.fitness
Another 2004 study found that fruit juice and high-sugar sports drinks were more likely to cause side pain than water or no fluid at all. This may be due to the fact that such drinks draw water from the peritoneal cells, resulting in increased friction. In addition, they can stay in the intestines longer than water, causing the intestines to put more pressure on the peritoneum.
With that said, to reduce the risk of side pain, you should not eat immediately before exercise. In addition, the portion of food taken should be small. By the way, you can’t play sports immediately after eating for other reasons that we talked about earlier.
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Finally, we note that pain in the side associated with physical activity quickly goes away after a person stops doing exercises or running. If it persists for a long time, perhaps its causes are completely different, so you need to consult a doctor.