Cramps and Stitch

Just about everyone who has ventured onto the exercise arena has experienced either a cramp or a stitch at some time.  These complaints can range from mildly uncomfortable to severely debilitating and 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 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.

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.  A fact sheet on fluid guidelines is available in the AIS Sports Nutrition website (www.ais.org.au/nutrition). 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.

What is stitch?

Stitch is a localised pain usually felt on the side, just below the ribs.  It is sometimes accompanied by a stabbing pain in the shoulder joint.  The pain can range from sharp or stabbing to mild cramping, aching or pulling.  Sometimes people can exercise through the pain however, usually the sufferer is forced to slow down or cease exercise.  The pain usually eases within a few minutes after ceasing exercise however some people experience some residual soreness for a few days, especially after severe pain.  Stitch seems to be more prevalent in activities that involve vigorous upright, repetitive movement of the torso.  Activities such as running (particularly when going down hill) and horse riding may be more prone to stitch but it can occur in any type of activity.

What causes stitch?

Scientists are unsure of the exact cause of stitch.  For some time, stitch was thought to be caused by a reduction in blood supply to the diaphragm, a large muscle involved in breathing.  It was thought that during exercise, blood was shunted away from the diaphragm and redirected to exercising muscles in the limbs.  This theory has now lost favour with scientists.  Both the diaphragm and the limb muscles need to work harder during exercise so it is unlikely that an inadequate blood flow is directed to the diaphragm.
Another popular theory is that stitch is caused by organs pulling on the ligaments that connect the gut to the diaphragm.  Ligaments that support organs such as the stomach, spleen and liver are also attached to the diaphragm.  Jolting during exercise may cause these organs to pull on the ligaments and create stress on the diaphragm.

A more recent idea is that stitch is caused by irritation of the parietal peritoneum.   Two layers of membrane (peritoneum) line the inside wall of the abdominal cavity.  One layer covers the abdominal organs.  The other layer (parietal peritoneum) attaches to the abdominal wall.  The two layers are separated by lubricating fluid, which allows the two surfaces to move against each other without pain.  The parietal peritoneum is attached to a number of nerves.  It is thought that the stitch occurs when there is friction between the abdominal contents and the parietal peritoneum.  This friction may be caused by a distended (full) stomach or a reduction in the lubricating fluid.

Eating and drinking inappropriately prior to exercise may exacerbate stitch by causing a full stomach or dehydration.  Poor fitness, an inadequate warm-up and exercising at high intensity may also be factors.  A sudden change in biomechanics such as increased stride length or frequency may increase the risk of stitch by affecting the way that the torso moves.

How can I avoid stitch?

• Eating too closely to exercise or consuming inappropriate foods and fluids seems to exacerbate the stitch.  High-fat foods, and foods and fluids with a high sugar concentration are more likely to cause problems.  The likelihood of stitch occurring may be reduced by allowing 2-4 hours before exercising after a large meal and choosing high-carbohydrate, low-fat and moderate to low protein options in the pre-exercise meal. 

• During exercise, it is possible that a full stomach contributes to stitch.  Concentrated fluids such as soft drink and cordial empty slowly from the stomach therefore are likely to lead to a fuller stomach.  Water and sports drink empty more quickly and are a better option.  It is also preferable to adopt a pattern of consuming small amounts of fluid at frequent intervals during exercise rather then trying to drink large volumes all at once. 

• Stitch may also be minimised by following a training schedule that progressively increases in intensity and duration.  Sudden increases in intensity are more likely to cause stitch.  It is much better to start at an easy level and slowly build up.

How should stitch be treated?

Sometimes the stitch eases if you slow down and drop your intensity for a period.  However, the most common way to alleviate stitch is to bend forward while pushing on the affected area and breathing deeply.  Sometimes this can be done while exercising but usually the pain eases more quickly when exercise is ceased.  Another option is to lie down while elevating your hips.

Does stitch indicate a more serious problem?

The stitch is rarely a sign of more serious problems.  However, any pain that is persistent and does not ease when exercise ceases should be investigated by a doctor.

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Written by Michelle MInehan and the Department of Sports Nutrition, AIS © Australian Sports Commission 2004