Cramps and stitches are very common. At some time or other, every athlete and school team player has suffered and cramp can severely compromise performance and cause individuals to worry about future events.

WHAT DO WE KNOW……

The 4minute video summary below gives a good overview on the causes of sport related cramping and side stitches. Given by Dr Metzl, it is part of the ‘Inside the Doctors Office’ series done for the RunnersWorld. Dr Metzl divides cramps into two categories, functional cramping, which includes stitches and nutritional cramping. Although he suggests 80-85% of cramping is nutritional, I think that this statistic is based on research in adult athletes. Although there is no doubt that nutritional cramping is common, I think the balance between functional and nutritional cramps in children playing school sports is more even.

Functional Cramp

Functional cramps occurring during exercise are described as a sudden, tight and intense pain in the muscle groups being worked. The pain can range from a slight twinge to an excruciating burning and may last for a few seconds, several minutes or until exercise stops.

What causes functional cramping?

The exact mechanism is still unknown but cramping is more likely in tired muscles or ones that are in a shortened position. Poor fitness, doing a new type of exercise or exercising at higher workloads than normal, all increase the likelihood of cramp. Side stitches are particularly common in children and have been linked to poor core muscle tone.

How to lower risk of suffering from functional cramp?

The Long Term Athlete Development plan (LTAD) recommends introducing strength and conditioning exercises and adequate stretching practises in tandem with sport specific training in children. Research shows that introducing a series of strength and conditioning exercises, post exercise stretching or the regular use of a foam roller lowers the frequency of muscle specific cramps.

Is a stitch really just a form of functional cramp ?

Dr Metzl thinks it is and many people agree but some scientists believe that stitches may actually be caused by irritation of the parietal peritoneum. Inside the abdominal cavity, there are two layers of membrane lining the inside wall, one layer covers the abdominal organs, while the other layer (parietal peritoneum) is attached to the wall. The two layers are separated by lubricating fluid allowing the two surfaces to move against each other without pain. A stitch maybe caused by friction between the abdominal contents and the parietal peritoneum. This would explain why stitches are more common after eating a meal (full distended stomach) and when athletes are dehydrated (reduction in lubricating fluid). Also the parietal peritoneum is attached to the phrenic nerve, which refers pain to the shoulder region and this could explain why some athletes associate side stitches with shoulder pain.

Nutritional Cramp

For the most part nutritional cramps feel much the same as functional cramps but they are not generally limited to a single muscle group and often begin in the fingers or toes. Nutritional cramps can also occur after exercise, whilst relaxing or asleep.

What causes nutritional cramping?

Again the research is not good and the mechanism isn’t known but there are a number of possible causes:-

• Dehydration
• Imbalances in mineral electrolytes—sodium, potassium, calcium, and magnesium.
• Carbohydrate depletion

DEHYDRATION

Although we know that muscle cramps can and do occur with severe dehydration and heat injury, it has been very difficult to prove scientifically. To date there is no conclusive evidence that consuming adequate fluid with or without electrolytes will totally prevent either nocturnal or exercise-associated cramp. Studies on runners, cyclists, and triathletes who have developed cramp have found that they are no more likely to be dehydrated than other competitors who have not suffered. However, dieticians working with athletes have noted that maintaining a proper fluid balance does help many endurance and team athletes to avoid cramps, particularly cramps occurring after exercise or at night.

ELECTROLYTES

SODIUM –  is one of the main electrolytes in body fluid, acting to maintain normal body-fluid balance and blood pressure and critical for nerve impulse generation and muscle contraction. Because of its importance, the body has a highly effective mechanism to regulate blood levels. If the sodium level starts to drop, the body produces the hormone aldosterone, which signals the kidneys to retain sodium. If sodium levels are too high, aldosterone secretion is inhibited promoting sodium excretion. Another hormone, antidiuretic hormone (ADH), also helps maintain normal sodium levels in body fluids by signaling the kidney to retain water and sodium. Research has shown that the levels of both aldosterone and ADH increase during exercise, helping to conserve the body’s water and sodium stores.

Sodium deficiency is not common, the body’s regulatory mechanisms are very effective and humans have a natural liking and appetite for salt. However, some individuals are known to loose more salt during exercise than others. This is often noticeable by the white lines on their sports clothes after exercise and these individuals may have to be more careful. Although still within the normal range, endurance athletes who experienced cramps have been shown to have lower postexercise serum sodium concentrations than those who did not develop cramps.

POTASSIUM – is another major electrolyte in all body cells and potassium with sodium and chloride are particularly key to the generation of electrical impulses in nerves and muscles. Potassium balance, like sodium balance, is regulated by the hormone aldosterone. Deficiencies or excessive accumulation are very rare but low blood potassium concentrations, called hypokalemia, can lead to muscle cramps and muscle weakness and high blood potassium concentrations also disturb electrical impulses and induce cardiac arrhythmia.

Even though little evidence is available to support a link between potassium intake and muscle cramps, it is quite interesting that most athletes (and non-athletes) think that eating a potassium rich banana is the best prevention for muscle cramps.

CALCIUM – is also involved in muscle contractions and in the generation of nerve impulses. Blood calcium is also tightly controlled and regulated by hormones. Individuals born with problems with calcium metabolism are known to be prone to muscle cramping but although impaired muscle contraction and muscle cramps are commonly listed as symptoms of calcium deficiency, most exercise scientists agree that low calcium intake is not likely to play a role in most muscle cramps. This is because if dietary calcium intake were low, calcium would be released from the bones to maintain blood concentrations and theoretically provide what would be needed for muscle contraction. This thinking, however, does not completely rule out the possibility that muscle cramping could be caused by a temporary imbalance of calcium in the muscle during exercise.

Despite the lack of evidence, circumstantial evidence does support the use of calcium for the prevention of cramps, with many dieticians stating that the addition of calcium rich foods to the diet has helped athletes they have worked with and who have had problems with cramping.

MAGNESIUM – plays an important role in stabilizing adenosine triphosphate (ATP), the energy source for muscle contraction and is also an electrolyte. Muscle weakness, muscle twitching, and muscle cramps are common symptoms of magnesium deficiency.

There is limited data on the links between magnesium status and muscle cramp in sport and the studies that there have been have shown mixed results. Magnesium supplementation has however been shown to help sufferers of ‘night cramps and there is a suggestion that sub-optimum magnesium intake could be linked to generalised muscle tension and tension headaches. Supplementation has also shown promise in pregnancy cramps.

CARBOHYDRATE

Inadequate carbohydrate stores have also been implicated as a potential cause of muscle cramps. Theoretically, it makes sense that hard-working muscles might experience cramping in association with the depletion of its fuel — carbohydrate. Athletes with a history of cramping during prolonged exercise should ensure that they consume adequate carbohydrate during exercise and in the days before and days following an endurance event.

ADVICE – How to 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.
• Make sure that you have a good balanced diet that is not deficient in any electrolytes
• Make sure you follow good hydration practices and consider using electrolytes during intense exercise particularly in hot weather
• Consider refuelling using carbohydrate during extended periods of high impact sport
• If you get a stitch or muscle cramp, resting and stretching helps to decrease the muscle contraction and allow the muscle to relax.
• Massaging the area may also help and applying ice can stop the spasm and help to relieve the pain.

How can I avoid stitch?

• Don’t eat to close to exercise and avoid high-fat and fibre foods which maybe more likely to cause problems. High carbohydrate foods are best.
• Immediately before and during exercise, athletes should avoid consuming highly concentrated fluids such as strong cordial or fruit juice, as they seem to increase the risk of stitches occurring during exercise. These type of drinks empty more slowly from the stomach than both water and sports drink, thereby leaving the stomach distended for longer.
• Adding strength and conditioning exercises to your training routine and maintaining strong core muscles can also help.

ALSO

Anecdotal reports from athletes have linked increased likelihood of cramp to creatine supplementation. Although this theory is interesting, studies that 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.