Liquid Intake On The Trails
Like all athletes, hikers need to replace some of the water they sweat or breath away to keep their bodies and brains functioning well. On hot days, dehydration means having less water available for sweating so dehydrated athletes overheat, become slower, get muscle cramps or headaches. Carrying water or exercise drink and sipping from it steadily prevents these problems.
Drinking too much water during strenuous exercise can also be dangerous, especially for less-fit athletes.
During hard exercise, blood flow to the kidneys is reduced so you don’t form much urine.
At rest, your kidneys adjust the saltiness of your blood by dumping water or salt as needed. Sweat is salt water. If you sweat but replace only water and your kidneys can’t correct the imbalance by dumping water, your blood becomes gradually less salty. Unfortunately, if your blood is not in a certain narrow range of saltiness, your muscles and nerves don’t work properly.
Having your blood salt concentration low enough to cause problems is called hyponatremia, and hyponatremia kills. Don’t make the error of thinking that more is better when it comes to drinking while exercising.
Water is heavy and you need to carry it on the trail, unless you will be frequently passing sources of drinking water. Carrying much more than you need makes for slower and less comfortable hiking. Figuring out how much water you’ll really need allows you to keep hydrated while maximizing speed and comfort.
GOOD TO KNOW
There is no valid rule of thumb that says drink X ounces or ml of water every Y minutes. A fit 150-pound adult on a hot, humid day can sweat away 3 pounds (1360 g) of water per hour if not more, but the same adult on a cooler, dryer day might lose only a pound (454g) or less doing equally strenuous exercise. Also, sweat rates vary between athletes under identical conditions so each person needs to figure their own water need, including adjustments for temperature, humidity and intensity of exercise. Keep track of how much you drink on various hikes and adjust what you carry accordingly. Precision is not needed. A few extra ounces or ml per hour or a few too few won’t make any difference.
For short hikes, up to an hour, water is for comfort. You can choose to bring it or to go without and just have a big drink after. Depending on temperature, the real need to consume water on a hike might kick in at one to two hours duration. It takes much longer to come back from dehydration than to stay hydrated, so when you go on longer hikes, consistently drink every 15 or 20 minutes. As a starting place, adults can drink a pint (0.5L) per hour and then adjust based on how that works out.
Signs That You Are Not Drinking Enough
Not needing to pee for two hours or more on the hike or in the first ½ hour after
Urine dark in color (like apple juice or darker) when you do pee
Headache or cramps if you have not been drinking much
Dry mouth/no saliva
Big thirst when you do get access to water
Losing more than 2 pounds (1kg) during a hike
Signs That You Are Drinking Too Much
Sloshy feeling in the belly
Needing to pee more than every hour
Gaining ANY weight during a hike
Headache or cramps if you feel like you’ve been drinking a lot
Pay attention to how much you drink and whether it is enough according to the criteria above and adjust accordingly for the next hike. Bring some extra for washing salt out of your eyes or wetting your shirt or hair on a hot day. With a bit of experience you’ll learn just how much to bring and intake on trailings of different lengths in different weather and you’ll be trailing strongly.
Trail on Trailblazers and Keep the Awareness,
Your Trailulive Coach and Trainer,
Scott Saifer
