Getting the water and salt intake balance right
Water is the only drink for a wise man. Henry David Thoreau
Keeping well hydrated is a balancing act between drinking enough to stay hydrated but not so much that essential salts are too diluted. While both can lead to serious medical conditions, they’re easy enough to avoid with proper planning and awareness.
Urine colour is a visual cue of hydration levels. In general, the better hydrated the body the lighter the urine colour.
The human body makes the best use of water when ingested in small amounts regularly, allowing time for water to be absorbed and used in the system. That’s why it’s important to drink regularly on a bushwalk. Hydration bladders make drinking small amounts regularly very easy.
Some people struggle to drink enough water. If so, try lightly flavouring water with cordial or setting a drinking goal, perhaps marking “drink-to” points on the water bottle. Note that flavouring water will render this water and perhaps the container unsuitable for meals or other drinks.
Caffeinated drinks like tea and coffee are mild diuretics, causing increased passing of urine. Drinking these can lead to dehydration if they’re drunk in large quantities or if the body isn’t used to them, but in small amounts such as on a bushwalk they provide similar hydrating qualities to water.
Due to the high sugar content, soft drinks and energy drinks are less effective at hydrating than water. High sugar concentrations in these drinks slows fluid absorption into the blood system. Some energy drinks also contain caffeine, guanine and preservatives which may have negative effects on performance. Occasionally, people react badly to these kinds of drinks, so it’s best to try these at home first, or better – just stick to water!
Dehydration Dealing with dehydration in the bush
Dehydration affects physical performance and occurs when the body loses water faster than it is replenished. When the overall body water content drops by 2%, dehydration signs and symptoms take effect.
| Condition | Signs and symptoms |
| Early dehydration 2% of water body mass loss |
Flushed skin Weariness Sleepiness Impatience |
| Moderate dehydration 4% of water body mass loss |
Apathy Muscle fatigue Nausea |
| Severe dehydration 6% of water body mass loss |
Headache Dizziness Shortness of breath Tingling in limbs Very dry mouth |
If someone in the group has signs of dehydration, stop in shade and administer first aid. First, apply DRSABCD: check for any danger and make sure you are still getting a response from the patient (continue to – SABCD if necessary). Remove the patient’s hot clothing and encourage them to drink small sips of water. Consider shortening the trip and not walking in the hottest time of day, about noon-2 pm. Check all the party for dehydration and encourage everyone to drink.
Electrolytes Why electrolytes are so important
Electrolytes are body salts necessary for our muscle and nerve function. As with body water, electrolytes too are lost via sweat, and must be replenished via eating healthy foods that are high in electrolytes. This applies in particular when bushwalking on hot days and when working hard.
In general, eating a balanced diet of fruits, nuts, vegetables and dairy is a healthy way of replacing salts such as sodium, chloride, potassium and calcium. This diet includes:
- Coconut water
- Leafy greens
- Tomatoes
- Celery
- Bananas
- Yogurt
- Nuts
- Beans
It’s not practical to carry some of these foods on a bushwalk, instead, stock up before and after the walk on items like yogurt and greens, and take nuts and fruit on the walk. Note that some food requires more water than others to digest.
There’s a huge amount of hype and media around sports drinks and their hydration power, although research shows there’s little difference between them and water. Their main selling point is to replenish electrolytes, although this is only needed for prolonged intensive exercise.
As sports drinks tend to be extremely sugary and filled with artificial flavouring, eating a balanced diet is a healthier alternative.
Hyponatremia Signs and symptoms of hyponatremia
Hyponatremia is a rare condition that occurs when the sodium content in the blood is too low. This causes fluid to move into the cells making them swell, and has been known to be fatal.
Hyponatremia may occur by drinking too much water or losing too much salt (via sweat), but also from organ abnormalities or reactions to medication.
Signs & symptoms of hyponatremia include:
- Headache
- Muscle cramps
- Heart palpitations
- Decreased consciousness
- Confusion
- Fatigue
- Lethargy
On a bushwalk, if hyponatremia is suspected, follow the DRSABCD action plan and apply first aid. Stop and rest in the shade, and encourage the patient to eat something high in sodium (e.g. biscuits, chips) or pure salt (keep sachets in first aid kit). Monitor the patient and call for help if the situation deteriorates.
Although rare, hyponatremia is becoming more common due to people drinking too much when exercising. It must be treated seriously as it can be life threatening, just the same as drinking too little water. In short, it’s about getting the balance of water and salt intake right.
So on a bushwalk, drink well according to the body’s water needs under various temperature conditions, eat well and have fun!