How Much Water You'll Need for Your Walk

Woman Drinking Water Walking on Beach
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When you go for a walk, it's important to drink enough water and other fluids so you don't get dehydrated. But it can take some planning to know how much to take along, or how often you should refill your water bottle or hydration pack.

How Much Water Should You Drink?

If you walk at a moderate pace (about 2.5 to 4 miles per hour) for 30 to 60 minutes on most days of the week, the good news is that you're meeting the American Heart Association's recommendation of 150-minutes of moderate-intensity exercise per week.

To stay hydrated during your walking workouts, the exact amount of water you should drink varies based on factors such as the duration of your walk, level of exertion and fitness, and even age. To help determine how much water you should drink during physical activity, fitness experts suggest the following methods.

Drinking to Thirst

Thirst is the best protection for athletes and exercisers when it comes to drinking the right amount. Research shows the body's natural thirst mechanism can determine how much water you should be drinking to avoid dehydration as well as water intoxication, also known as hyponatremia.

Drinking to thirst is simple and effective: Drink when you are thirsty. Don't drink if you aren't thirsty.

Drinking to thirst is useful for walking workouts lasting up to 90 minutes, particularly at a moderate intensity and in cooler weather conditions. If you're walking at a brisk pace and/or are walking in very hot weather, you may need to drink more water than usual and your body should naturally respond to thirst accordingly.

Most walkers who exercise at a moderate intensity should be able to stay adequately hydrated by simply responding to their natural thirst cues. However, people over the age of 65 may respond to thirst differently and would benefit from closely monitoring how much they're drinking and when.

Programmed Drinking

In this common drinking regimen used by athletes, your water intake before, during, and after your workout is pre-established. Programmed drinking helps prevent dehydration and fluid loss and also helps athletes avoid drinking too much water as well. Seek advice from a registered dietitian to help you calculate your ideal water intake.

If you're training for a race walking event, especially at longer distances, you may benefit from a more regimented hydration protocol.

How Much Water Should You Carry?

Common vessels for carrying water include 16-ounce disposable bottles, 20-ounce refillable sports bottles, or hydration packs of various sizes (50/70/100 fluid ounces or 1.5/2/3 liters). The amount of water you will need to carry in your bottle or hydration pack during your walks will also vary based on the distance and intensity of your workouts. You may need to try a few different amounts before you determine what works best for you.

If you find that you are running out of water and are still thirsty, you should bring more water with you next time. Keep in mind that if you're low on water and still have a fair amount of distance to go you should sip slowly to ensure that you don't run out.

It's possible to drink too much plain water and wash out your body salt, resulting in hyponatremia, which can be dangerous. As a general rule of thumb, don't force yourself to drink too much and only drink when you're thirsty.

When to Use Sports Drinks

When you walk for over an hour, especially if you're sweating, you may want to begin with a sports drink that replaces sodium and other electrolytes you are losing. Alternatively, you could have a snack that has some salt. But be sure to keep drinking enough fluids. You could bring a powdered sports drink with you to add to your water or switch to a prepared sports drink.

Consider the Weight of Water

Water and sports drinks weigh quite a bit, with a pint (500 ml) of water usually weighing in at about a pound. If you want to save on weight but need more water, you'll need to make a plan in advance and find refill locations for your bottle or hydration pack along your route.

What Should You Drink on Distance Walks?

For a workout of 10 kilometers (6.2 miles) or more, the International Marathon Medical Directors Association (IMMDA) recommends drinking a sports drink and not diluting it with extra water, or alternating your sports drinks with water. The carbohydrates and electrolytes in sports drinks help the body absorb water faster and provide you with necessary energy. If you dilute the sports drink, you decrease the benefits.

Many walkers and runners (particularly those wanting to lose weight) tend to ignore this advice in order to take in fewer calories. During a marathon or race, you should drink carbohydrate-containing sports drinks for performance and endurance. For walking workouts, you can try a low-calorie sports drink to replace salt without adding extra calories.

However, the IMMDA also recommends that during a marathon, participants drink whichever beverage most appeals to them, relying on their body to know whether they need more sodium or more water. Race directors and walking event hosts should have both water and sports drinks available at water stops.

This is good advice for walkers and runners on long training walks and runs as well. Have both available to you and drink whichever appeals to you at the moment.

How Much Should You Drink on a Distance Walk?

There are dangers in drinking either too much or too little water. Drink too much and you risk hyponatremia, which is low blood salt level and fluid overload. Drink too little and you risk becoming dehydrated.

Weighing yourself before and after exercise can often help you know whether you are drinking too much or too little. The IMMDA guidelines state that a weight loss of more than 4%, or any weight gain, are warning signs that justify immediate medical attention and indicate that you are drinking too much or too little. By weighing yourself and adjusting how much you drink on your longer training sessions, you will know whether you need to drink more or less.

Keep these simple tips in mind when drinking to thirst for longer distance walks or runs:

  • Don't drink at every water stop at an event just because it is there or your companions are drinking.
  • Rely on your thirst unless you discover it is leading you wrong, from weighing yourself before and after a workout.

The slower you are, the less water you will likely need to drink. For example, a fast runner may need 4 liters of fluid for a marathon, while a walker or slow runner needs only 2.5 to 3 liters for the entire event.

Calculating Your Fluid Needs

Remember that your fluid needs may change based on the weather, your conditioning, sweat rate, age, and other factors. The IMMDA provides this method of determining your fluid needs:

One-Hour Sweat Test

  1. Weigh yourself nude before a walk or run.
  2. Walk, run, or alternate walking/running at race pace for one hour, just as you will do during the race. (IMMDA recommends one hour to get the sweat rate you will have during the endurance event.)
  3. Write down how much you drink, in ounces, during the 1-hour walk or run.
  4. Weigh yourself nude after you finish the 1-hour walk/run. Subtract from starting weight. Convert the difference in body weight to ounces (multiply pounds by 16).
  5. To determine your hourly sweat rate, add to this value the volume of fluid consumed (from Step 3).
  6. To determine how much to drink every 15 minutes, divide the hourly sweat rate by 4. This becomes the guideline for fluid intake every 15 min of a walk/run.
  7. Record the weather and conditions on your test day. Do the test again on a day with different weather and conditions, so you can see how your sweat rate reacts to different conditions.

A Word From Verywell

Drinking when you are thirsty is an effective strategy for walking at a moderate intensity. But during long-distance workouts or events, your body is under extreme stress and you need to have access to enough fluids. Don't risk running dry. It can be wise to wear a hydration pack to ensure you will have fluids available to you when your body signals that it's time to hydrate.

Remember that your thirst mechanism may be off if you are working out in extreme heat and have not yet acclimated to it, or alternatively, you're walking in cold weather. In these cases, you may need to schedule your hydration rather than strictly rely on your thirst.

4 Sources
Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. American Heart Association. American Heart Association recommendations for physical activity in adults and kids.

  2. Hew-Butler T, Rosner MH, et al. Statement of the Third International Exercise-Associated Hyponatremia Consensus Development ConferenceClin J Sports Med. 2015;25(4):303-320. doi:10.1097/JSM.0000000000000221 

  3. Hew-Butler T, Verbalis JG, Noakes TD. Updated fluid recommendation: Position statement from the International Marathon Medical Directors Association (IMMDA). Clin J Sport Med. 2006;16(4):283-292. doi:10.1097/00042752-200607000-00001

  4. Kenefick RW. Drinking strategies: Planned drinking versus drinking to thirstSports Med. 2018;48(Suppl 1):31-37. doi:10.1007/s40279-017-0844-6

Additional Reading

By Wendy Bumgardner
Wendy Bumgardner is a freelance writer covering walking and other health and fitness topics and has competed in more than 1,000 walking events.