I was toward the end of a long 9 mile hike with over 3,800 feet of elevation gain when we came across a family with a sick teenage boy. Being a Wilderness First Responder, I checked in with them to see if I could help. It turned out that the boy had dehydration and heat exhaustion. The family called Search and Rescue to come, as the boy needed an IV. He couldn’t keep anything down and they weren’t very receptive to more help. We left them and directed help when we passed them on the trail.

My conversation with the family really frustrated me for a few reasons. (Years later, I it will still rile me up.) One, it turns out that this is a common occurrence for the boy. He dehydrates easily. Two, he finished all his water before he got to the first of the three peaks, meaning that he had almost nothing to drink for over a third of the hike, as there was a place to fill up water at the final peak. (What size bottle did he have? And if you know he dehydrates easily, why did he just have one?) Three, it was a humid 80-90°F in the mountains. It was hot and the hike was not easy.

On hot days, I think of this boy and how ill prepared his parents were. I’ve led hikes in 114°F weather and got everyone through. Largely because of proper planning and expectations.

Here are my tips for staying hydrated.

Drink Throughout the Day

Constantly sipping is better than drinking your water all at once, as your body can absorb it better. For this reason, you’ll always find me with a bottle next to me. It helps because when you start a workout, you’re starting in a hydrated state versus a dehydrated one.

Start your day off with a glass of water and finish it the same way.

Carry the right amount of water

A good rule of thumb on a general day is to drink half your body weight (in pounds) in ounces. For someone who weighs 150lbs, they should drink at least 75oz (about 2.25L). On hotter days or days with a long hard workout, this should actually be higher to potentially even higher. Some people may need almost 10L a day.

On a short relatively flat 2-4 mile hike, you may not need anything or be able to make due with a small bottle and hydrate afterwards. However, if it’s hotter and you’re doing a hard workout, you need more water on you.

Andy Galpin, PhD, a professor of Strength and Conditioning at the University of Fullerton, has a formula he uses for his athletes to stay hydrated that is a variation of the one above. Take your body weight (lbs) and divide that by 30 to determine how many ounces of water you should drink every 15 minutes. Using the same person above who weighs 150lbs, they should drink 5 oz of water every 15 minutes. That equals 20 oz (about 2/3 L) in one hour. (Expect to see Galpin mentioned again below for more on this.)

On the day that I mentioned above, I had a full 3 Liter water hydration system with an extra 3 Liter bladder in case myself or my two other hiking mates ran out. (Though we all filled up at the hut, because it was hot, we were drinking a lot, and mountain water is amazing.)

We CAN drink too much water. If we drink too much water it can wash out the micronutrients we need for balance, which is why IV bags aren’t water alone. They align similarly to the composition of our blood.

Think Beyond Water

While water is important, when it’s hot, we sweat. When we sweat we lose other micronutrients that are crucial for our health and function. The biggest are sodium (Na) and chloride (Cl) (basically salt), followed by potassium (K), magnesium (Mg), and glucose. By having a drink that helps to replenish these nutrients, we can actually absorb the water better and be more hydrated for performance.

For anyone just going about their day, we get the majority of the nutrients from food making water sufficient to drink. Even if you’re going out for a long hike or doing low level activities, making sure that you eat can help replenish us. I love peanut butter pretzels as a snack on trail for this reason. Add in an apple, banana, chocolate, and other foods to be set.

Sometimes, we need to add something to our water to be in a better position to perform and there are plenty of drink choices out there with different electrolyte balances. Dr. Galpin suggests drinks that have a 4:1 ratio of NaCl to K, some Mg and glucose. A good salt level to aim for is around 1,000-3,000mg per Litre of water.

This actually matches what I would drink during my marathon training a few years ago. I despise the flavors of most performance drinks, so I would make my own. I’d add some salt to watered down juice to fill up my water bladder for long runs. (I maybe could have used more potassium though…)

I always carry a bag of salt with me when I hike and it’s amazing how much it can perk someone up when they’re tanking. They just need that little kick. You can add a bit of salt directly to your water bottle or bladder to keep that level more consistent. (Know that pink salt can tint your bladder and you definitely need to rinse it and clean it after if you add any mix or flavoring. Trust me, you don’t want bacteria growing in it.)

Know the symptoms of dehydration

It’s far better to prevent dehydration than to improve it later. Symptoms can be different for each person, which doesn’t help. Always seek medical attention if you suspect severe dehydration or symptoms are not improving with rest and rehydrating.

Thirst can be helpful, but isn’t always accurate. You may already be dehydrated by the time you’re thirsty and you may not be thirsty because you’ve had enough water and need some salt.

If your urine is dark, you need more water. If it’s too clear, you may be drinking too much and need some electrolytes. You may also not need to urinate, because you’re sweating so much.

You may have a headache, which is almost always a sign for me that I need more water. There can be confusion, fatigue, and/or dizziness.

If you learn anything from this, please let it be – Don’t be like the family at the beginning. Be smart when it’s hot and stay hydrated.

Kate Hamm combines her 15+ years of experience in the fitness industry and high-end resort program development into sought after wellness coaching and adventures at AnamBliss. Visit www.anambliss.com for more information on coaching services and future retreat dates and locations.