Hyponatremia

A potentially fatal condition, hyponatremia most often occurs in exercise lasting four hours or longer and results primarily from drinking too much fluid. It is made worse by not replacing sodium losses. Severe cases may involve seizures, increased intracranial pressure, fluid in the lungs, and respiratory arrest. To avoid sodium depletion, ensure foods contain sodium and check the back of sports drinks for sodium content. 

Symptoms:

• Headache
• Fatigue
• Nausea
• Lack of co-ordination

Note - these symptoms are very similar to those for dehydration.

Prevention:

• Monitoring your fluid intake. Drink enough fluid so that you do not feel thirsty and so that you are urinating at normal periods. If urination becomes frequent and clear-coloured, you may be drinking too much.
• Ensure your food content contains sodium.
• Drinking isotonic sports drinks instead of water. isotonic drinks contain salts and thereby assist in maintaining the correct salt balance in your body. Participants should try isotonic drink during training and ensure they can drink it comfortably.
• Use sports dinks at 50% concentration in the two to three days pre-event in preference to water to pre-hydrate. Normal intake should be approximately 5ml / kg (i.e., 375ml if you weigh 75kg) five times per day for base hydration.
• If you experience any of the symptoms of hyponatremia, consult the medical staff at the nearest checkpoint. DO NOT PROCEED and DO NOT simply continue drinking water.