CoolColJ
Here is some info from the Australian Institute of Sport-
http://www.ais.org.au/nutrition/FactCramp.htm
Cramps and Stitch
Just about everyone who has ventured out to do some exercise has experienced either a cramp or a stitch at some time in their lives. These complaints can range from mildly uncomfortable to severely debilitating but there is no question that they are a great source of frustration to everyone from recreational exercisers to serious athletes. Unfortunately, scientists know very little about the two conditions and how to avoid them. Consequently, there is a lot of folklore surrounding the topic, making it difficult to know exactly how to deal with these problems.
What is cramp?
Cramp is a sudden, tight and intense pain that most commonly occurs in the leg muscles especially the gastrocnemius (calf), hamstrings (back of thigh) and quadriceps (front of thigh). It can range from a slight twinge to an excruciating pain, and may last for a few seconds or several minutes. A cramp can be a one-off occurrence or repeat several times before the muscle relaxes and the pain goes away.
What causes cramp?
Cramp is caused when a muscle involuntary and forcibly contracts and does not relax. While this seems to be due to an abnormal stimulation of the muscle, the exact mechanism is unknown. Cramp is more likely to occur in tired muscles therefore poor fitness or exercising at high workloads can increase the likelihood. Inadequate stretching may also contribute.
Dehydration may contribute to cramp especially when fluid and sodium losses are high. Sodium is involved in initiating nerve signals that make muscles contract. A deficit of sodium and fluid may “irritate” muscles causing them to contract uncontrollably.
Cramp has been attributed to the depletion of potassium and minerals such as calcium and magnesium. However, this idea does not have strong support as very little potassium, calcium and magnesium is lost during exercise. Also deficiency is rare as these substances are abundant in the diet. It has been suggested that magnesium is relocated in the body during exercise rather than lost in sweat. Therefore, a magnesium imbalance in relation to other electrolytes (sodium and potassium) may be involved. Further evidence needs to be gained in this area.
The use of creatine has been linked to cramps, based on anecdotal reports from athletes, and the hypothesis that a creatine-loaded muscle cell may become so “full” with the storage of creatine and fluid, that the integrity of the membrane is disrupted. Although this theory is interesting, studies which have followed the cramping and injury outcomes of groups of athletes have not found any difference in the prevalence of problems occurring in creatine users and non-users.
How can I avoid cramp?
Allow adequate recovery and rest for muscles after hard training sessions.
Increase strength and fitness. Stronger, fitter muscles are more resilient to fatigue and therefore cramp. Be cautious when changing speed or intensity especially during the later stages of exercise. Fatigued muscles take longer to adapt to increased workloads.
Wear comfortable, unrestrictive clothing and footwear.
Stay well hydrated during exercise by drinking appropriate amounts of fluid. See Fluid - Who Needs It? for guidelines. Sports drinks are a good option as they help to replace sodium losses, especially when sweating at high rates. In most cases, salt tablets are not recommended. However, during ultraendurance exercise (particularly in very hot weather or when sweat losses are high) it can be necessary to be more aggressive in the replacement of sodium. Sodium intakes of approximately 0.25-0.7 gram per hour may be necessary for ultraendurance exercise lasting more than 3-4 hours. This may require the use of salty foods (i.e. Vegemite sandwiches, crackers, pretzels, potato crisps) or special products such as electrolyte powders or tablets to keep pace with sodium requirements. Speak to a Sports Dietitian if you think this applies to you.
How should cramp be treated?
Stretching helps to decrease the muscle contraction and allow the muscle to relax. Massaging the area may help to alleviate pain. When cramps are severe, applying ice can stop the spasm and help to relieve pain. Rest and replacing fluid losses will also bring improvement.
Does cramp indicate a more serious problem?
In most cases, cramps are a temporary event and do not lead to serious problems. However, sometimes cramps can indicate a more serious medical condition. You should always see your doctor if cramps are severe, occur regularly, fail to improve with simple treatment or are not related to obvious causes such as strenuous exercise.
