How to Hydrate Hiking


By ANNIE RITCHIE / April 18, 2023

Hey there, fellow outdoor enthusiast! When it comes to hiking, we all know how crucial it is to stay properly hydrated during our adventures. But figuring out just how much water to bring on a day hike can be a bit tricky, right? That’s why in this blog post, we’re going to dig into the science of hydration, chat about the factors that affect how much water you need, and even explore some counterarguments on the topic. So, let’s get started!

The Science of Hydration

First off, let’s talk about why hydration matters. Our bodies are made up of about 60% water, and water plays a crucial role in many physiological processes, and in the functioning of the body’s cells and organs. It helps regulate our body temperature, cushions our joints, transports nutrients, and aids in digestion, among many other functions. When we hike, we lose water through sweat, breathing, and even urine production, which can lead to dehydration if we’re not careful.

Dehydration occurs when the body loses more water than it takes in, leading to a decrease in blood volume, which, in turn, affects the body’s ability to regulate its temperature. Symptoms of dehydration include thirst, dry mouth, fatigue, dizziness, and dark-colored urine. In severe cases, dehydration can lead to heat exhaustion, heatstroke, and other medical emergencies.

Factors to Consider When Determining Water Needs on a Day Hike

Now, when it comes to determining how much water to bring on a day hike, there are a few key factors to consider. The length of the hike, the terrain, and the weather are all important considerations.

As a general rule of thumb, it’s recommended to drink about 0.5 to 1 liter of water per hour of moderate hiking in moderate temperatures. However, this can vary depending on factors such as your individual body weight, age and fitness level, overall health and sweat rate.

Length of the Hike

The length of the hike is perhaps the most crucial factor in determining water needs. As a general rule, hikers should drink at least half a liter of water per hour of hiking. So for a hike lasting 3-4 hours, it is recommended to carry at least 2 liters (or about 68 ounces) of water per person. But I would argue that this applies to a moderate hike in optimal hiking conditions. If the hike is more prolonged, or if the hiker will be exerting themselves in hot and dry conditions, more water may be necessary.


The terrain is an essential factor to consider. Hikers who will be trekking uphill or through rough terrain will likely require more water than those hiking on flat ground. If you’re tackling a strenuous hike with steep terrain, you may need to up your water intake to account for the extra exertion.


Additionally, hikers who are exposed to hot and dry conditions will need to drink more water than those who are hiking in cooler temperatures. If you’re hiking in hot weather, as well as doing what you can with appropriate clothing, you will need to drink even more water to compensate for the increased fluid loss through sweat and breathing.

Hiker’s Health

The hiker’s age, weight, and overall health should also be taken into account. Older adults and those with certain health conditions, such as kidney disease or diabetes, may require more water than younger, healthier hikers. Similarly, individuals who weigh more or who have a higher body mass index (BMI) may require more water than those who are smaller.

It’s a good idea to monitor how much you’re drinking and pay attention to your body’s signals of thirst to ensure you’re staying properly hydrated throughout your hike.

How Do You Keep Track Of Your Water Intake?

I have heard hikers say they find it hard to manage their water intake on hikes as they find that carrying too much water can weigh them down and slow them down on the trail. While it’s true that water can add extra weight to your pack, proper hydration is crucial for your safety and performance on the trail. Dehydration can lead to symptoms such as dizziness, fatigue, and impaired cognitive function, which can increase the risk of accidents and hinder your overall hiking experience.

Some hikers may argue that they prefer to rely on their thirst as an indicator of when to drink water, rather than following a strict schedule. While it’s true that our bodies are equipped with mechanisms to signal when we’re thirsty, research has shown that our thirst sensation may not always be reliable, especially during physical activity. In fact, by the time we feel thirsty, we may already be slightly dehydrated. So, it’s important to strike a balance between listening to our bodies and being proactive in maintaining hydration during a hike.

Can You Drink Too Much Water?

Despite the overwhelming evidence supporting the importance of hydration on a day hike, some hikers are concerned that drinking too much water can be harmful. This argument stems from the belief that overhydration can lead to hyponatremia, a condition in which the body’s sodium levels become dangerously low. While hyponatremia can be a serious condition, it is relatively rare and is more commonly associated with endurance events such as marathons. What is far more important for the average hiker is to stay hydrated.

So, I Need To Hydrate Then?

Yes, staying hydrated during a day hike is essential for maintaining optimal health and avoiding medical emergencies. The appropriate amount of water to bring on a hike varies though.

As a starting point, hikers should drink at least half a liter of water per hour of hiking, but be aware that that number might increase in various circumstances. The overwhelming evidence supports the importance of staying hydrated during physical activity. As such, hikers should err on the side of caution and bring more water than they think they will need to ensure they stay properly hydrated.

When it comes to hiking hydration, it’s important to consider factors such as the length of the hike, terrain, and weather, and to drink enough water to stay properly hydrated. Listening to your body’s signals of thirst is important, but it’s also essential to be proactive in maintaining hydration, especially during physical activity.

So, make sure to pack enough water on your day hikes, stay mindful of your body’s needs, and enjoy your outdoor adventures safely and comfortably! Cheers to staying hydrated on the trails!