What causes cramps?

The Cause of Cramps

The Australian Sports Commission (AIS) describes cramps as a, “tight and intense pain that most commonly occurs in the muscle groups directly involved in the exercise task.” Even though most people will suffer from cramps at some point in their lives, there is little medical consensus on what causes them because few doctors are studying them.

wat_causes_crampsSource: Peter Griffin

There are various theories about why muscles cramp. However, none of these theories have been conclusive. In the New York Times article, “A Long Running Mystery, the Common Cramp,” Dr. Andrew Marks, the chairman of the Department of Physiology and Cellular Biophysics at Columbia University, is quoted as saying, “There is no really convincing biological explanation for muscle cramps.” Thus, any advice or research that claims to be definitive should be questioned.

For example, it has long been held that dehydration is the major reason behind most cramps. However, according to the AIS, there is little scientific evidence that this is the case. In fact, “studies of marathon runners and other ultra-endurance athletes have shown no difference in the hydration status of those experiencing [cramps] and those that have not.” Thus, dehydration cannot solely be blamed.

There are theories that do have some scientific backing, though. According to the Mayo Clinic, if a person has too little potassium, calcium, sodium, or magnesium, this deficiency can lead to cramps. Dr. Michael Bergeron from the College of Georgia explains that excessive sweating can lead to a depletion of these nutrients, which makes nerves sensitive. He advocates drinking sports drinks like Gatorade. But, as the New York Times mentions in its article, his research is sponsored by Gatorade. Thus, his credibility could be called into question.

Another common cause of cramps is nerve compression. Nerve compression can be caused by holding a muscle in a certain position for too long. According to Dr. Charles van der Horst from the University of North Carolina, deep muscle massages can loosen this compression. In fact, this is how he treats his own cramps. In addition to massages, the NHS suggests multiple stretches to loosen the muscles and prevent nerve compression.

It is important to note that serious medical conditions can cause cramps. For example, nerve compression could be indicative of a more serious condition, like a pinched nerve. A pinched nerve, according to Mount Sinai Hospital, will cause cramping accompanied by numbness and muscle weakness. Thus, if one experiences cramps, numbness, and weakness, he or she should contact a doctor.

Another serious medical condition, peripheral artery disease (PAD), is caused by the narrowing of blood vessels. According to the U.S. National Library of Medicine, PAD is caused by arteriosclerosis (hardening of the arteries). Basically, fatty materials (plaque) build up on the walls of the arteries, which makes them stiffer and narrower. Once this happens, muscles do not receive enough blood and oxygen and will cramp. Generally, the people who suffer most from PAD are those with high cholesterol, diabetes, heart disease, hypertension (high blood pressure), and kidney disease. Those who smoke or who have had a stroke are also more likely to develop PAD.

While the cause of common cramps remains a mystery, the AIS suggests some ways to avoid them. They suggest taking enough time to recover after difficult training sessions, increasing strength, taking caution when changing speed and intensity, and wearing comfortable clothes. Additionally, while there may be little evidence that dehydration causes cramps, it is still a good idea to fully hydrate, especially before intense workouts.

Hopefully, more doctors will start studying this phenomenon so that the question of what causes cramps can be fully answered.

The Australian Sports Commission (AIS)
“A Long Running Mystery, the Common Cramp,”
Mayo Clinic
Mount Sinai Hospital
U.S. National Library of Medicine