Have you ever been dehydrated? Proper dehydrated? Dizzy, lightheaded, nauseous. Thirsty. Really thirsty. Only, by the time your really thirsty, and you've been on the trails for a long while, you're way past the point of where just a small bottle of water would reduce your fluid deficit.
Hiking with Impunity has been on quite a few trails this summer. The most worrying sights have been hikers out on a very hot, summer day with nothing but a bottle of water in one hand. Your typical bottle of water has about 500ml of water in it. 500ml is exactly the amount of water that you should be drinking before you start hiking. And then there are the hikers we ran into on the trails without any means of hydration whatsoever, looking exhausted and thirsty - a bad combination if you still have a while to go on the trails.
But, can you drink too much water? And, is water all you'll need for your time on the trails? The answers are yes and no.
Let's start at the end with urine. The amount and color of your urine can be a very good indicator of whether someone is well-hydrated. How much should you be urinating to demonstrate that you are not dehydrated? Many texts indicate that an amount between 0.5 - 1.0 ml/kg/hr of urination is appropriate. When was the last time you brought a measuring cup on the trails with you and collected your own urine? Exactly. When you're out on the trail you're going to have to use the highly scientific "Rules of Thumb":
- If your urine is super-concentrated (read: really dark), you're not drinking enough water. Your urine should flow easily and be nice and clear
- If your thirsty, you're already low on fluids
- If your not sweating and/or your mucus membranes are dry, you are very low on fluids
- When on the trails, try to stick with the following plan: drink about 200ml of fluid every 20 to 30 minutes
Depending on the season, the heat index, the strenuousness of the hike, and other factors that increase your body's perspiration, you may want to remind yourself of this additional rule of thumb: you will sweat around 1/2 to 1 quart of fluid for every hour that you walk in the heat. If you purchase a 2- or 3- liter hydration bladder, that should contain the minimum amount of fluid needed to get you through a 3 to 6 hour hike in the heat. Depending on the circumstances, this still may not be enough!
Hydration bladders are virtually a necessity for hiking, which makes the purchase of a backpack to carry the hydration bladder equally essential. Hydration bladders are stored in your backpack, while a hose with a valve of some kind is threaded out of the bag for you to drink from. Generally, you bite down on the valve to draw water from the pack. Because of the convenience of a hydration bladder, it is our experience that people will be more likely to stay well-hydrated with a bladder versus yanking out bottles from their backpack. Regardless, you should still pack a bottle or two of water as spares (you never know when the hike may take you longer than anticipated).
Can you have too much water? The answer is a resounding yes!
When you sweat, you lose salt and other electrolytes. Sweat contains approximately 3 grams of salt per liter. Over the course of an eight hour hiking day in hot weather, you could potentially lose around 2 to 2.5 grams of salt. By only replenishing water and not balancing the fluid with salt and other electrolytes, you run the risk of developing hyponatremia, which basically means "too much water". Symptoms of hyponatremia can include but are not limited to the following: headache, dizziness, weakness, fatigue, heavy sweating, lack of thirst, lightheadedness, etc. Unfortunately, there is quite a bit of overlap between the symptoms of hyponatremia and dehydration. Being that the treatment for each condition is diametrically opposite to each other, you can imagine, it's important to get it right!
It's important, therefore, to supplement your hydration bladder with electrolyte and carbohydrate containing fluids (which can be found in most supermarkets and convenience stores) as well as bringing salty snacks on the trail with you. We are not advocating for bringing salt tablets! The best rule of thumb is always the well-worn phrase, "Everything in Moderation". For a 3 liter hydration bladder, we will generally fill it with 2 liters of water and 1 liter of a sports drink.
Severe dehydration, heat exhaustion, heat stroke, and hyponatremia can all be life-threatening, causing coma and possibly death. It is important to remember that if you or someone you are with develops any of the above signs or symptoms while on the trail, to contact a medical professional and/or call 911 as soon as possible.
It is very easy to stay well-hydrated. Please take our advice: regardless of the season you're planning (even winter, where you will lose water to evaporation from respiring cold air), bring enough fluids and electrolytes to maintain an appropriate fluid balance.
**Please remember: this article is for entertainment and informational purposes only, and should not be taken as the advice of a medical professional. Much of the information found in this article can be found in medical and hiking texts. For more information about how much water you should be drinking, please consult a medical professional. People with significant medical problems, such as congestive heart failure, may exacerbate their condition depending on the amount of hydration they consume.