Introduction
Muscle cramps are extremely common, with an estimated 60% of adults experiencing them on occasion. Muscle cramps generally worsen and increase in frequency with age, and can be linked to a myriad of factors including, deficiency of certain nutrients, exercise, and underlying medical conditions (such as diabetes).
Although the scientific research is fairly limited, within sports medicine, it is widely accepted that dehydration plays a role in cramp (source) particularly in relation to Exercise Associated Muscle Cramping (EAMC), which is defined as ‘a painful, spasmodic, and involuntary contraction of skeletal muscle that occurs during or immediately after exercise.’ (source)
Symptoms of dehydration
On average, water accounts for approximately 60% of the total body weight of an adult human, and it is therefore unsurprising that dehydration can cause a number of symptoms, such as poor physical and cognitive performance, headaches, nausea, fatigue, and weakness, and if left untreated can lead to a life-threatening medical emergency.
Dehydration is extremely common: research suggests that a large percentage of Americans do not drink the recommended amount of water per day, with one consumer survey finding only 22% of the 2000 participants, met the recommended daily intake.
Dehydration and muscle cramps
Excessive perspiration is a common cause of dehydration, and cramp frequently occurs during or immediately after exercise and is particularly prevalent amongst those who exercise strenuously or work for long periods of time, in hot weather. In order to relax, your muscles require sufficient fluid particularly, during or after intense exercise, and it is for this reason why dehydration may lead to cramping.
However, there is also evidence to suggest that the loss of key electrolytes through perspiration, may also contribute to Exercise Associated Muscle Cramping, with one study finding that an electrolyte beverage decreased cramp susceptibility and pain in a group of cramp-prone participants. (source)
In order to function properly, our muscles require a sufficient balance of electrolytes, (sodium, magnesium, potassium, and chloride) and it is thought that an imbalance or deficiency can contribute to muscle cramps.
Preventing dehydration
Rather than trying to ‘cure’ dehydration once it occurs, it is better to try and prevent it completely by ensuring you are consuming sufficient fluids daily.
The U.S. National Academies of Sciences, Engineering, and Medicine recommend a minimum daily fluid intake of approx. 15.5 cups (3.7 liters) of fluids a day for men and approx. 11.5 cups (2.7 liters) of fluids a day for women. Fluids can be obtained from water, other beverages, and food.
For those experiencing ‘heat cramps’ including both Exercise Associated Muscle Cramping and work-related cramping, research suggests that consuming an electrolyte drink rather than plain water may be preferable (source)
Summary
There is evidence to suggest that both dehydration and loss of electrolytes can contribute to muscle cramps, particularly during or after exercise, and therefore, ensuring you consume sufficient fluids (including electrolyte drinks if cramp occurs after exercise) may be an effective means of prevention/reduction.
However, it should also be noted that dehydration/electrolyte-loss may not be the sole cause of muscle cramps, and other additional measures may also be adopted to help reduce/prevent such issues.
