Exercise-associated muscle cramp (EAMC) is a painful involuntary contraction of skeletal muscle that occurs during or after physical activity. EAMC has multiple potential causes, making it difficult to prevent or treat. Risk factors include a history of EAMC, high intensity and long duration of exercise, and underlying chronic disease. EAMC is more commonly associated with endurance-type activities and team sports. Although EAMC is common, it can be a rare occurrence for some athletes, while others may experience it frequently and severely. There is still much uncertainty surrounding the causes and treatment options for EAMC. Further research is needed to develop effective prevention and treatment strategies.

Exercise-associated muscle cramping (EAMC) has long been attributed to dehydration and electrolyte loss, however, new evidence suggests that its genesis is due to changes in the nervous system. This theory, known as altered neuromuscular control, suggests that EAMC ensue when several factors (e.g. fatigue, inadequate conditioning, and muscle damage) increase alpha motor neuron excitability. A “cramp journal” is suggested to prevent EAMC by working closely with each athlete to identify trends in their medical history and noting when EAMC occurs. EAMC predictors include: prior history of EAMC, faster race times, and previous muscle injury or damage. This new evidence is important to reevaluate the evidence for each theory on EAMC genesis and could potentially save lives in high-stress athletic events where lives are at risk.

Exercise-associated muscle cramping (EAMC) is a common issue for marathon runners, but the aetiology and management of this condition is not well understood. The most commonly cited hypothesis is the "muscle fatigue" hypothesis, which suggests that EAMC is the result of an abnormality of neuromuscular control at the spinal level in response to fatiguing exercise. This is based on evidence from epidemiological studies, animal experimental data, and electromyogram data recorded during bouts of acute cramping after fatiguing exercise. While early anecdotal reports linked cramps to sweating and changes in serum electrolyte concentrations, more recent research suggests that serum electrolyte concentrations and hydration status are not associated with EAMC. Overall, the cause of EAMC remains unclear, but research suggests that premature muscle fatigue may play a role.

The study aimed to test the hypothesis that nociceptive stimulation of latent myofascial trigger points (MTrPs) increases the occurrence of local muscle cramps. The study carried out an experiment to see if a bolus injection of glutamate into a latent MTrP would increase the occurrence of muscle cramps. The results showed that glutamate and isotonic saline injections into the latent MTrPs induced higher peak pain intensity than into the non-MTrPs. The findings also suggest that nociceptive muscle stimulation of latent MTrPs is more likely to cause muscle cramps. This study highlights the importance of understanding MTrPs and their role in the occurrence of pain and muscular discomfort. It provides valuable information for clinicians when treating patients with myofascial pain syndrome.

A clinical trial has shown that hydroquinine is more effective than a placebo in treating muscle cramps in healthy adults. The study, which was randomised, double-blind and placebo-controlled, involved 68 women and 44 men who reported at least three muscle cramps per week. During the treatment period, participants were randomly given 300mg of hydroquinine or a placebo. Those taking the hydroquinine reported a median of eight fewer cramps and three fewer cramp days. The drug was described as safe to take in the short-term and effective in preventing muscle cramps, with this effect lasting beyond the treatment period.