Combien d'eau apporter en randonnée ? Eh bien, personne n'aime porter beaucoup de poids lorsqu'il part en randonnée et l'eau est lourde. Mais souffrir de déshydratation, l'un des risques de ne pas s'hydrater correctement, n'en vaut pas quelques kilos en moins sur votre sac à dos. Alors, quelle est la bonne quantité pour que vous restiez hydraté sans vous casser le dos ?
We all did it, one way or another. We were too cautious, carried enormous bottles of water and did not drink half of them. Or we were too confident and ended up begging our hiking mates for a sip of water here and there. Therefore, is there a middle ground and if so which one it is? Here is a guide on how to calculate the right amount of water for your next adventure and some useful tips to be at your best.
How Much Water to Bring on a Hike
It depends.
That’s the short answer.
But what does it depends on?
Here are the factors you need to take into consideration when getting ready for a hike.
Rule and Factors
Rule
As human beings, we should be drinking 2L of water on a normal day. Of course, when hiking we need to drink even more water. The rule of thumb for a hiker is 1/2L per hour for a hike on even terrain by average temperatures. Starting with 1/2L per hour as your base, here are the factors you need to take into consideration to take the right amount of water with you.
Difficulté
It just makes sense that if you are doing a difficult hike on uneven terrain and with a lot of ascents, you would be sweating more and therefore would need to hydrate more. Therefore, when looking at the route, check the elevation and adjust the amount of water you would be carrying accordingly. I explain later in this post how to calculate the right amount of water to bring based on the incline.
Durée de l'accord
As we saw before, the rule is 1/2L of water to be consumed every hour. So of course the longer the hike, the more water you would need to bring. An important fact to also take into consideration when looking at the duration of a hike is that you can only go as fast as the slowest member.
Who are you going with?
What pace do they walk at?
Ask yourself those questions to gauge how long the hike should take you and therefore how much water you should carry with you.
Temperatures
When hiking in the summer heat, the rule differs and you would need to count 1L of water per hour in order to stay hydrated. Don’t forget that even when the temperatures are low you should still sip on your water. Drinking cool water when it is cold outside might be the last thing on your mind but it is equally important to hydrate in winter than in summer.
Tip: If you don’t want to drink cold water, take an insulated bottle with you to carry a hot drink.
Contenu connexe : Tips to Hike in the Summer Heat
Intensity
What are you planning to do: a stroll in the countryside fields or a hike marathon in the hills? Based on the type of activity, you would exercise more or less and therefore need to hydrate more or less often.
Sweat rate
We see it in every hiking group: some people would begin melting from the start of the walk and some won’t break a sweat until they reach the finish line. We are all different and our body reacts differently to exercise. So, know yourself and remember the more you sweat, the more often you would need to hydrate.
Do the Maths
Planning and preparation are key when it comes to gauge how much water to bring on a hike. Before the big day, check the route to see if there is any reliable source of water on the way for you to refill your bottle. When I say reliable, what I mean is that you need to ensure the water source won’t be dry when you get there.
To know how long the hike will take you, use Naismith’s Rule. Developed by William W. Naismith, a mountaineer, in 1892, the formula is a follow:
1 hour for 3 miles (5km) + 1 hour for every 2,000 feet (600m) of ascent.
To know the distance and the ascent of a hike you can either refer to the hike description if you are going on a guided walk or use a paper map or app on your phone to check the mileage and elevation.
So if you are going on a 12 miles (22km) hike with 300m of ascent it will take you:
12 miles = 4 hours
300 m = 1/2 hour
12 miles + 300 m = 4.5 hours
Add to this time for snack and lunch breaks, picture time stops and toilets breaks, it should therefore take you around 5.5 hours to complete this hypothetic hike.
With the rule of 1/2L for every hour you hike, you then get:
4.5 x 0.5 = 2.25L of water
And now you know how much water you should take on hike!
How to Hydrated Yourself
It might seem a silly question, but knowing how much water to bring on a hike is pointless if you do not hydrate yourself correctly before, during and after the walk.
Hydration rules
Drink often
This is the first rule. You need to drink often by taking small sips of water at a time rather than big chugs once in a blue moon. The reason for it is simple. It is due to the way your body assimilates water. If you drink big chugs, your body would then pass the water quickly, resulting in you having to stop for a nature break more often.
Drink before
When starting a hike you need to be well-hydrated if not you would spend your time playing catch up. To start out on the right foot it is recommended to drink at least 0.5L of water 2 hours before the start of a hike.
Drink after
The same rule applies after a hike. You need to keep on drinking to get the fluid in your body back to its normal level.
Replace electrolytes
When you are exercising, your heart rate increases resulting in your feeling hot. As a response, your body produces sweat as a way to cool off. When you sweat, your body loses electrolytes. Electrolytes are minerals that are important for the body to function. Their role is to regulate nerve and muscle function.
To replace the loss, it is advisable to mix electrolytes into your water. You can find them as tablets or powder, but note that powder ones can get really messy to open on a hike.
Tip: Avoid adding electrolytes to your main hydration system. Instead, carry a spare bottle of water to mix with electrolytes.
Drink more at altitude
The higher you do, the more you need to drink. Due to the lack of oxygen at altitude, you breathe faster and therefore your body loses more water.
Conseils
Keep water available
One of the most common mistakes is to place your water bottle in the main compartment of your backpack. This means that every time you want to drink, you need to stop to get your bottle out.
The risk?
You start feeling too lazy to get your bottle after a while and therefore stop hydrating yourself as much as you should do. If you are using bottles of water, place them in the side mesh pockets of your backpack for easy access. Alternatively, you can opt for a hydration bladder and you won’t have to worry anymore about accessing your water!
Wear sun protection
We might not think of it at first, but sunburns impact the level of fluid in your body. They draw the water towards the surface of the skin away from the body. Therefore, you need to drink plenty of water to replace the loss of fluid. To avoid this situation, simply wear sun protection.
Dress appropriately
If you wear too many layers of clothes when the temperatures are rising, you would end up sweating more and therefore needing to drink more water. To know what to wear for hiking, read my guide ici.
Set a timer
If you are the forgetful type, set a timer to remind you to take a sip of water every 20 minutes.
Keep an eye on the level
It is easy to be carried away when we are hiking. From the beauty of the landscape to an interesting discussion with your hiking buddy, and without knowing it, you run out of water! Keep an eye on your intake to make sure you have enough water to last until the next water source or the end of the hike.
Be cautious
Better to be safe than sorry or in our case better to be safe than dehydrated. Bring more water with you than what you think you would need. We never know, the source of water you planned to stop by to refill might be dry, it might turn out to be hotter than expected or simply the hike is more challenging than what you thought. Carrying extra water means extra weight, but it can save your life.
Risks
So what happens if you did not take enough water with you or if you did not take the time to hydrate yourself properly during the hike? Or what could happen if you drink too much?
The first thing you need to do to check if your fluid levels are fine (and it is a bit gross)is to check the colour and the smell of your urine! It is the way your body tells you how well (or not) hydrated you are. Urine should be clear yellow and don’t have a smell. However, if you notice that your urine is of a dark yellow colour and has a strong smell, then it means that you are under-hydrated.
On the other hand, if you constantly need to take a toilets break and the colour of your urine is clear this could mean that you are over hydrated.
So what exactly are dehydration and overhydration?
Dehydration
According to the NHS, dehydration is when your body does not have enough water to function properly,
Symptoms
- Feeling thirsty
- Dry mouth
- Fatigue
- Headache
- Dizzyness
- Disorientation
- Poor movement coordination
- Slurred speech
- Dark urine
Treatment
First, if a member of your hiking group is showing any of the above symptoms, STOP immediately. Dizzyness, disorientation and poor movement coordination on the trails can result in accidents. Then, this is what you should do:
- Find shade
- Sit down or lie down
- Drink sips of water mixed with electrolytes
- Get a damped shirt and bandana to cool down the body temperature
Overhydration
Overhydration is more common among runners and marathoners than hikers, but it is still worth mentioning it. It happens when you drink too much water and the electrolytes and salts in your body become diluted. As a result, your cells are not functioning properly and it can be fatal.
Symptoms
- Cramps
- Headache
- Nausea or vomiting
- Muscle weakness
- Mentally confused
- Discolouration of hands, feet and lips
Treatment
- Stop hiking
- Stop drinking
- Find shade and lie down with feet elevated
- Take salt tablets
How to Carry Water
Knowing how much water to bring on a hike is a good start, but you also need to look at how you will carry the water. There are three ways: hydration bladder, hard bottles and collapsible bottles. Let’s look at each one of them to help you decide which hydration system is best suited for your needs.
Hydration Systems
Hydration Bladders
| Pros | Cons |
|---|---|
| Sip on the go | Hard to clean |
| Contain up to 3L | Cannot see how much you have left |
| Deplete as you drink | Hard to refill at a water source |
| Can add ice cubes to the water | Water in the tube can get warm or freeze |
| Hand-free | Not durable |
| Easy to carry |
Hard bottles
| Pros | Cons |
|---|---|
| Durable | Does not deplete as you drink |
| Can see the level at a glance | Take space |
| Can carry hot drinks if insulated | Contain up to 1L depending on the design |
| Easy to refill | Heavy |
| Easy to clean |
Collapsible bottles
| Pros | Cons |
|---|---|
| Deplete as you drink | Lack durability |
| Lightweight | Hard to clean |
| Can be attached to the backpack | Can puncture |
| Easy to refill |
Related content: Hydration Bladder vs Water Bottle
Water filters
Don’t forget when you are going for a long hike and you need to refill your bottle or reservoir to take a water filter with you. Never drink water straight from the source as it contains bacteria and can cause you to be ill.
They are different types of water filters such as pump, UV pens or tablets. Choose a lightweight one as you do not want to add more weight to your backpack. Water in itself is already heavy, 1L = 2.2 pounds/1kg. Also, remember to always carry a backup with you: if your UV pen batterie dies, have some tablets “just in case”. You do not want to be without drinkable water!
Final Thoughts on How Much Water to Bring on a Hike
Hydrating yourself while exercising is of utmost importance and should not be disregarded. When preparing for a hike, checking how much water you should bring is important as choosing the correct outfit and packing food.
With an easy formula at hand, you all have left to do is the math!
Have you ever run out of water on a hike? Let me know your story in the comments.
Like these tips? Pin them!
[…] Only the combination of the right food and the correct amount of hydration will make the perfect hike. To know more about how much water you should carry on a hike, click here. […]