Muscle cramps are painful and can occur in all types of sports and are usually associated with muscle fatigue and/or dehydration. The muscle cramping is commonly seen in the calf and hamstring muscle groups.

Even when the muscles are immediately stretched to relieve the cramping, it often returns as soon as the muscle is next contracted e.g. when the athlete takes his/her first step.

What are the causes of muscle cramping?

Causes of muscle cramps during exercise appear to be two possible causes. The first category is related to skeletal muscle overload and fatigue (American College of Sports Medicine, 2008). In this case, the activity in the part of the neuromuscular system that initiates muscle contractions (muscle spindles) is increased while the part that inhibits contractions (Golgi tendon organ) is inhibited. This type of muscle cramping only affects the specific muscles that are fatigued.

The second category of exercise-associated muscle cramps is caused by excessive sweat losses associated with a decreased level of electrolytes (e.g. sodium). Electrolytes are minerals that dissolve in the body e.g. sodium, chloride, magnesium and potassium. Electrolytes have a direct effect on muscle cramping because they regulate fluid balance, nerve conduction and muscle contraction.

The body has a complex system for cooling itself as the core temperature of the body increases during exercise. The body primarily cools itself by redirecting its blood supply out towards the surface capillaries in the skin (where the blood is cooled) and the second system is by sweating.

What might make you more susceptible to muscle cramping?

Factors associated with increasing the risk of muscle cramping in overload or fatigue-related muscle cramping include:

• Older age

• Poor stretching habits

• Insufficient conditioning

• Cramping history

• Excessive exercise intensity/duration

• Metabolic disturbances

• Sweat rate

• Sweat sodium concentration

• Dietary intake

How can I treat muscle cramps?

The effective treatment of muscle cramps is dependent on the cause. For those suffering from overuse/ fatigue cramps the most effective treatments are passive stretching, muscle massage, icing the affected muscles and contraction of the muscle on the opposite side of the muscle cramping (e.g. if your hamstring is cramping, contract your quadriceps).

For athletes suffering from muscle cramps prompted by excessive sweating and sodium deficit, the same treatments as above can be immediately applied to reduce the pain/spasm as well as consuming fluids with additional sodium.