How to Drink Right on Long Distance Walks to Avoid Dangers

Dehydration and Hyponatremia are Both Dangers for Long Distance Walkers

Brisk Walking
Brisk Walking. Robert Daly/OJO Images/Getty Images

Keeping enough fluids and salts in your body during a long distance walking event such as a marathon, 20-miler, or half-marathon is crucial to finishing feeling good. Getting hydration right can prevent spending time in the medical tent getting an IV or a scary trip to the emergency room. Don't end your race with a ride in the sag wagon or an ambulance—learn to drink right.


Dehydration is losing too much fluid from your body. You'll lose fluid due to perspiration as well as simply due to breathing.

Signs of dehydration include dry mouth, fatigue, dizziness, stomach ache, back pain, headache, irritability, and decreased urination. What urine you pass may be very dark yellow or gold.

The basic rule of thumb is to start a walk having had 16 oz. of water (a pint or a half liter), and then replenishing with a cup of water every 15 to 20 minutes. That is about a water bottle full an hour, about a half liter or a pint. End your walk with a big glass of water.

While you are walking, drink whenever you feel thirsty as well. Water works well as a replenisher for walks of up to an hour. For longer walks and those where you are sweating a lot, you should then think about replenishing electrolytes (salt) as well, using a sports drink. See more details in drinking guidelines for distance walkers and runners from the International Marathon Medical Director's Association.

Hyponatremia (Loss of Sodium or Body Salt)

Sweating removes both water and salts (electrolytes) from your body as you walk. Depending on the humidity, you may not notice how much you are sweating. For walks of over an hour, replenishing your electrolytes with sports drink is also important to prevent hyponatremia.

Signs of hyponatremia include nausea, headache, cramps, confusion, slurred speech, bloating and swollen hands.

It is recommended to drink one bottle of sports drink for every two bottles of water. Eating salty snacks such as pretzels during long walks is another source of salt. You might even consider using one of those little packets of salt you see at fast food restaurants—some races hand those out on the course.

On long distance courses such as the marathon or half marathon, walkers and slow runners are at risk of drinking too much plain water and flushing out their body salts, resulting in getting dangerously sick with hyponatremia. Let thirst be your guide rather than pushing too much water.

You can also be at risk after you finish your walk. Replenish fluids, but don't overdo plain water. Ensure you are balancing fluids with salty snacks or drinking electrolyte-replacement sports drinks.

Getting Hydration Right

Weigh yourself immediately before and immediately after a long walk. If you are getting dehydrated, your weight will drop from the loss of water. If you are losing body salt and drinking too much plain water without salt, you will gain weight. Keep records of what and how much you drank, sweat level, salt, etc. and adjust so you are not gaining or losing during the walk.

How to Carry Enough Water and Sports Drink on a Long Walk

How do you carry along sports drink on a long training walk where you won't have any support? Assuming you have a source of water, buy powdered sports drink mix and mix it with your water. It adds only a little weight to your pack and could keep you out of the emergency room.

Use this walking water calculator chart to see how much water and sports drink you'll need during a long walk, and make plans for how you'll get refills.

If the event or race provides water stops with sports drink and water, it is still essential to carry your own water and sports drink. You may become thirsty between water stops, and if you don't drink when thirsty, you are putting yourself in danger. Even well-run events may run out of cups, sports drink or water at the water stop you were relying upon. Faster and slower walkers may come upon stops not yet set up or already closed. Wise walkers always carry their own water and sports drink, just in case.

For ideas on the best packs and water carriers, see these choices:

6 Deadly Quotes About Water and Sports Drink on Long Walks

Anne Thimm heard plenty of excuses for not drinking enough water and sports drink at the Breast Cancer 3-Day Walk. Walking 20 miles a day for three days in hot weather, those excuses could put you in the hospital. Here's her list and her comments on why this is deadly thinking:

1. "I hate sports drinks! I won't drink them."
If you don't drink electrolyte replacement sports drink on long distance walks, you could easily become a victim of hyponatremia. While salty snacks are good, they are not a total substitute for the electrolytes in sports drinks. However, you might try some of the newer alternatives such as electrolyte replacement energy chews or electrolyte replacement gummy bears. You can find these at running shoe stores, but be sure to buy those that say they replace electrolytes.

While undiluted sports drink is the safest choice as it has a known concentration, you might start by mixing your sports drink at half strength until you are able to tolerate it. There are a wider variety of electrolyte replacement drinks available than in the olden days when Gatorade first debuted. Try different kinds until you find you you prefer.

2. "I walked the entire event last year and didn't drink any sports drinks."
You were either lucky or you have a unique metabolism. This year, you might not be so lucky. More importantly, the person you are telling this to may think that they can also make it without sports drinks. Their metabolism is different from yours. Your testimonial might lead them to risky behavior.

3. "I need to drink something, but I only like purple (or orange, or green) sports drinks. This stop doesn't have my flavor. I'll wait for the next stop."
Chances are that if you will only drink a certain flavor of sports drink, you won't find it anywhere on the walk. Don't plan on an assortment of every flavor of drink at every stop. Drink whatever is available.

4. "There are no cold drinks at this stop. I'll wait until the next one."
Don't wait, drink it even if it is warm. Odds are, if one stop is out of ice cold drinks, the next place might not have them either. It may not taste as good as when cold, but you will still be absorbing the water, salt, and sugars your body needs.

5. "I'm on a diet, and I don't want the calories."
You are on an intense endurance event, and you need the calories during exercise. Your walking training day or racing day is not a day where you should restrict calories. You'll only build your muscles and endurance if you are keeping them well-supplied with enough fluids and fuel.

Was this page helpful?
View Article Sources
  • American College of Sports Medicine Position Stand: Nutrition and Athletic PerformanceMedicine & Science in Sports & Exercise. 2009;41(3):709-731. doi:10.1249/mss.0b013e31890eb86. 
  • Maharam, LG. "IMMDA’s Revised Fluid Recommendations for Runners and Walkers." IMMDA. 6 May 2006.