Hydration is one of the most underestimated aspects of hiking, but also one of the most important. Drinking too little (or inappropriately) can compromise physical performance, mental clarity, and, in severe cases, lead to heat stroke or kidney problems. Drinking too much can also cause problems, such as hyponatremia (excessive dilution of mineral salts). In this article, we’ll look at:
- Signs of dehydration
- Common hydration mistakes when trekking
- How much water to bring
- When and how to drink while walking
- What to drink besides water (and what to avoid)
- How to fix it if you’re already dehydrated
Signs of Dehydration: When Your Body Sends You Warning Signals
Often, we realize we’re dehydrated too late. Here are the signs to watch out for:
- Intense and persistent thirst (but not always present at the beginning)
- Dry mouth, chapped lips
- Heachache
- Dark and infrequent urine
- Muscle cramps
- Sudden tiredness, drop in energy
- Dizziness or feeling confused
- Tachycardia or labored breathing
Caution: when dehydration is advanced, you no longer feel thirsty. In that case, you’re already in the risk zone.
Common hydration mistakes when trekking
1. Drink only when thirsty.
Many hikers wait until they feel thirsty before drinking. In reality, thirst is already a symptom of mild dehydration.
Solution : Drink small amounts every 20-30 minutes, even if you’re not thirsty.
2. Setting out with too little water:
A very serious mistake, especially in summer or on trails where there are no water sources.
Solution : Always carry at least 1.5–2 liters for short hikes, 3–4 liters for long treks or in hot climates.
3. Not knowing the route:
Not knowing where (and if) you’ll find drinking water sources can leave you exposed at the most crucial moment.
Solution : Study the map and note the sources. Bring a water filter bottle or water purification tablets if in doubt.
4. Drinking too much at once.
Some people drink large quantities at rest stops and then nothing for hours.
Solution : The golden rule is constant and even hydration : drink in small sips.
5. Neglecting to replenish mineral salts.
Water alone, especially if you’re sweating profusely, can dilute too much sodium and other electrolytes in your blood.
Solution : Alternate water with drinks containing mineral salts or add isotonic sachets to your water bottle.
How much water should you really carry?
The ideal amount depends on:
- Duration of the route
- Climate (temperature and humidity)
- Difference in altitude (the higher you go, the more you sweat)
- Access to water sources
- Your personal needs
Indicatively :
| Type of excursion | Minimum recommended quantity |
|---|---|
| Short walk (< 2h) | 0,5–1 L |
| Day trip | 1,5–3 L |
| Challenging summer trekking | 3–4 L |
Tip : If it’s very hot or you’re above 2000m, consider +0.5L for each additional hour.
When and how to drink
Proper hydration is proactive , not reactive. Here are the basic rules:
- Before the hike : Drink 300–500 ml of water at least 30 minutes before starting.
- During : Drink even just a couple of sips every 20–30 minutes. Use accessible water bottles or a hydration system (CamelBak).
- After : gradually rehydrates and replenishes mineral salts.
If you drink too much at once, you may feel heavy. It’s best to drink small amounts regularly.
What to drink besides water?
Water is essential, but not always sufficient. Here’s what you can bring:
Excellent allies:
- Isotonic drinks (commercial or homemade): replenish mineral salts.
- Water with lemon and a pinch of salt : simple and effective.
- Cold unsweetened herbal teas : excellent in hot climates.
- Diluted juices (such as apple or blueberry) : These provide natural sugars and a little flavor.
To avoid:
- Too sugary drinks : they increase thirst.
- Alcoholic beverages : further dehydrate.
- Carbonated drinks : not very effective, often irritating to the stomach.
How to Avoid Dehydration on Multi-Day Treks
If you’re going on a multi-day hike or a long walk:
- Study the supply points in advance.
- Bring water purification tablets or filters (such as Sawyer Mini or LifeStraw).
- Prepare rehydration solutions (e.g. mineral salt sachets such as Polase).
- Drink even in the bivouacs, before going to sleep and as soon as you wake up.
What to do if you’re already dehydrated?
- Stop walking immediately.
Look for shade or a cool place. - Drink slowly but steadily.
If you are very dehydrated, drinking too much at once can cause nausea. - Replenish salts and sugars
An isotonic drink or a mix of water, salt and sugar can help. - Monitor for serious symptoms
If you feel dizzy, confused, or have a racing heart, call for help .
In conclusion: the 7 golden rules for proper hydration while trekking
- Don’t wait until you’re thirsty to drink.
- Drink little and often.
- Know the route and available water sources.
- Adjust the quantity to the type of trail and climate.
- Replenishes mineral salts, especially if you sweat a lot.
- Avoid sugary, carbonated, or alcoholic drinks.
- Always carry a filtration system if the route requires it.