WPPC’s Guide on Cramping in Athletes


A muscle (or even a few fibres of a muscle) that involuntarily (without consciously willing it) contracts is in a “spasm.” If the spasm is forceful and sustained, it becomes a cramp. Think of it on a spectrum where a few fibres involuntarily contracting is a light spasm this can progress all the way to the entire muscle (± surrounding muscles) is sustaining an involuntarily contraction. In the sporting arena cramps are most commonly seen in the calf and hamstring muscles.

Muscle cramps can last anywhere from a few seconds to a quarter of an hour or occasionally longer. It is not uncommon for a cramp to recur multiple times until it finally goes away. The cramp may involve a part of a muscle, the entire muscle, or several muscles that usually act together.

There are a huge range of cramp types (and their associated causes). Some of the types not covered in this blog include:

  • Night (or nocturnal or rest) cramps
  • Tetany cramps (relating to a neurological cause of cramps)
  • Injury (a protective mechanism)
  • Dystonic cramps (“writer’s cramp”, opposite muscle groups contract)

There appear to be two key causes for muscle cramping in the ‘healthy’ athlete. Although further research is needed to better understand the underlying physiology of both, the literature provides a basis for understanding the problem and how to prevent muscle cramps from occurring.


The first category of exercise associated muscle cramps is related to skeletal muscle overload and fatigue. According to this theory, the neuromuscular systems imbedded in the muscles for the purpose of maintaining safe control of muscle contraction are affected. Where is goes wrong is that the part of the neuromuscular system that initiates contractions is increased while the part of the neuromuscular system that reduces contractions is decreased. Because of this the muscle is inundated with messages to contract by the nerves that conduct messages from the brain to the muscle.

Muscles that are overused and fatigued may be at a higher risk for muscle cramping due to the effects of the fatigue on the neuromuscular system. What is unique about this type of muscle cramping is that it would only affect the specific muscles that are fatigued and one would not see a generalised system muscle cramping as one would see with a case of dehydration-based muscle cramping.


The second category of exercise-associated muscle cramps is widely known and better understood.  Dehydration is commonly recognised as a cause of muscle cramping in athletes. The cause of the cramps is excessive sweat losses associated with a decreased level of electrolytes (specifically sodium).

Sweat is important as it helps maintain the temperature of the body. However, it also depletes the body’s store of water and electrolytes.

As the water and sodium content of the body decreases through sweating, the muscles can begin to systemically cramp. Sodium is the key electrolyte in the formula because sodium helps the body to retain water, especially in the muscle fluid spaces. Without a high enough concentration of sodium, the water that the athlete drinks is excreted without being distributed throughout all of the body’s fluid compartments.

What are electrolytes and why are they linked to muscle cramping?

Electrolytes are minerals that dissolve in the body as electrically charged particles. They include sodium, chloride, magnesium, and potassium. Electrolytes have a direct effect on muscle cramping because they regulate fluid balance, nerve conduction, and muscle contraction.

Why are some people more prone to cramping then others?

  • Different sweat rates
  • Different sodium concentrations in sweat
  • Diet variations

How can I treat muscle cramps?

The effective treatment of muscle cramps is dependent on the cause. For athletes suffering from overuse or fatigue muscle cramps, the most effective treatments are:

  • passive stretching,
  • massage,
  • icing of the affected muscles, and
  • contraction of the muscle on the opposite side of the muscle cramping (e.g. if the hamstring is cramping, contract the quadriceps muscle group to relax the hamstring muscle group).

Athletes suffering from fatigue-related muscle cramps will not be able to continue their activity without further cramping. These athletes need time for their muscles to heal and recover before trying to compete again.

For athletes suffering from muscle cramps prompted by excessive sweating and a sodium deficit, the same treatments as above can be immediately applied to reduce the pain and muscle spasm. However, along with the stretching, massage, and applied ice, these athletes need to consume fluids with additional sodium.

How much fluid and how much sodium?

Research from 2008, suggests immediate consumption of a “.5L carbohydrate-electrolyte drink with 3.0g (or one teaspoon) of salt added and thoroughly mixed consumed all at once or over 5 – 10 minutes” has proven successful at relieving muscle cramps and preventing future severe cramping. As the cramping resolves, these athletes may be able to continue competing at their normal intensity.

Prevention of cramps

There’s no proven strategy. This is why there is a vast range of opinions on how to prevent.

  • Regular muscle stretching
  • Correction of muscle imbalance and posture
  • Adequate conditioning for the activity
  • Avoid provocative drugs (this includes diuretics, caffeine and alcohol)
  • Incorporate plyometrics and eccentric muscle strengthening in training (doesn’t just mean the training you do with Brian!)
  • Consideration given to recovery – warm down, nutrition, stretching

Hopefully this blog has answered more questions then it has created! Happy training and playing!

Please contribute to this discussion with your own cures of cramping!