Feeling thirsty? You’re not alone. Seventy-five percent of Americans suffer from chronic dehydration, according to the Institute of Medicine. Because dehydration not only affects athletic performance, but also overall health and well-being, understanding the basics of hydration is key.


Water, like oxygen, is essential for life. You can only survive 3-5 days without water! Besides helping to maintain life, water performs several other important roles throughout the human body, including:

  • Transporting glucose and oxygen into your muscles.
  • Serving as a critical component of your brain, blood, muscles, and bones.
  • Aiding digestion of food, helping to convert it to energy you can use.
  • Removing metabolic byproducts like carbon dioxide from your hard-working muscles.
  • Regulating body temperature, especially during your workouts when your muscles generate 20 times more heat energy than a body at rest.

Even with all of its benefits, drinking water and staying hydrated is one of the most overlooked components in fitness. In fact, it’s been reported that more than 40 percent of regular gym-goers are at least partially dehydrated during their workouts.1

The bottom line is that dehydration can have a significant effect on performance. Anyone, from runners to lifters, can become dehydrated if fluid loss is greater than fluid intake. It’s as simple as that. And dehydration can lead to reduced performance, headaches, fatigue, and muscle cramps.

According to Dr. Rob Wildman, Chief Science Officer of Dymatize Nutrition “there is a lot that we know about how water or hydration status impacts strength performance and training results. Most of the research to date has focused more on endurance athletes. We need to better understand how muscle cell hydration status impacts acute strength training as well as long term benefits.”

Learn Hydration Basics

Old recommendations for hydration were drinking eight 8-ounce cups of water a day. These recommendations, however, are old news. “The Institute of Medicine (IOM) recommends a total daily water intake of 3.7 liters (15 cups) for the average adult male and 2.7 liters (11 cups) for the average adult female,” says Jennifer Christman, RDN, a corporate dietitian at Medifast. “However, water needs will vary depending on the individual’s age, gender, geographic location, activity level and temperature. You should utilize the IOM guidelines for fluid intake and make adjustments from there.”

Since there isn’t one magic number for everyone, most individuals can monitor hydration levels simply through thirst. This means drinking water consistently throughout the day, starting immediately upon waking. “The body does not make water, so it must be replenished throughout the day for the body to run efficiently and for general health,” explains Christman. “Fluid losses occur continuously from skin evaporation, breathing, urine and stool.”

Additionally, when thinking about hydration, it’s important to remember that water isn’t the only way to get the necessary fluids. Christman reminds people that hydration can come from other beverages, such as tea and coffee, and from fruits and vegetables. So, depending on what you’re eating throughout the day, you don’t need to rely solely on chugging water to stay hydrated.

Stay Hydrated During Sedentary Activities

Hydration during sedentary activities — such as sitting at your desk at work or having an outdoor picnic — is the best way to put the hydration basics to use. In these cases, you aren’t going to be sweating and losing sodium like you would while performing vigorous physical activity, so you don’t need to add much to the basics to stay within healthy levels. The exception is if it’s unusually hot outdoors and you’re losing water and sodium through sweat.

When it comes to the best thing to drink on an average day, water will always be the right choice. “Plain water is cheap and calorie-free, and nothing hydrates the body like plain water,” Christman says. “Sports drinks add extra calories, mostly in the form of added sugar, and the average person doesn’t need a sports drink to stay hydrated.”

As you are going through the day, keeping track of how much fluid you are consuming (like through Livestrong.com’s MyWater app) in is an option, but most people can measure their hydration levels through thirst and urination. A good rule of thumb to remember is that if you’re feeling thirsty, it’s possible you’re already dehydrated. It’s important to not wait until you’re dying of thirst to drink water, but you also shouldn’t let this guideline frighten you into drinking too much water, which can result in hyperhydration and a diluting of your blood.

“Usually, you should be using the bathroom every two to three hours,” says Amanda Turner, RD, who is a dietitian at the University of Colorado Anschutz Health and Wellness Center in Aurora, Colorado. “The color should always be a pale yellow. If it is darker or you are going less frequently, it is a good indication you are dehydrated.”

Another important thing Turner stresses during sedentary activity is that thirst can be mistaken for hunger, causing people to overeat. If you’re drinking water throughout the day, not just when you’re thirsty, it can help eliminate overeating or unnecessary snacking.

Keep Hydrated During Exercise

If you’re exercising, your hydration routine will be much different than your normal routine. It’s important to go into exercise hydrated, so drinking water regularly is still just as important as hydrating throughout your workout.

Hydrate before, during and after exercise in order to avoid dehydration. During your workout it’s important to understand that thirst cues aren’t always as reliable as they are throughout sedentary activity. “Thirst cues can’t keep up with what you need during exercise,” says Turner. “Athletes should turn to calculating sweat rate, for example, as an alternative.”

During the summer months, calculating sweat rate is especially beneficial because your body sweats more due to intense heat. Christman explains that losing just two percent of your body weight in fluid can compromise your performance. Weighing yourself before and after exercise will let you know how much you lost in sweat so you can properly replenish those fluids post-workout. “A 1- to 3-percent change in body weight indicates minimal dehydration,” Christman says. “A 3- to 5-percent change indicates significant dehydration, and more than a 5-percent change indicates serious dehydration.”

Additionally, during intense physical activity that lasts more than 60 minutes, it’s important to add some sort of electrolyte supplementation to your hydration routine. Though water is optimal for workouts under an hour, adding electrolytes to fuel longer workouts will help replenish what your body is losing. Turner explains that when you sweat you lose sodium, which is needed for proper muscle contractions. Thus, it’s important to monitor which ingredients are in your secondary fluids. “One common misconception is that coconut water is a good hydration item during workouts,” Turner says. “While it is not bad generally, as a sports beverage it is high in potassium and not sodium. Something higher in sodium is going to be the better choice during activity.”

Christman agrees with this and adds that sports drinks are most appropriate for those exercising intensely for over an hour, working outside in the heat or for elite athletes to replenish glycogen stores, electrolytes and optimize performance. She recommends the American College of Sports Medicine (ACSM) guidelines when it comes to exercise and hydration.

“According to the ACSM, to maintain hydration during exercise drink 16 to 20 fluid ounces of water or sports beverage at least four hours before and eight to 12 fluid ounces of water 10 to 15 minutes before exercise,” Christman says. “During exercise, drink three to eight fluid ounces of water every 15 to 20 minutes when exercising for less than 60 minutes, or drink three to eight fluid ounces of a sports beverage every 15 to 20 minutes when exercising for longer than 60 minutes.” After exercise, you should check your body weight (as explained above) and urine color and correct your losses within two hours after exercise. “Drink 20 to 24 fluid ounces of water or sports beverage for every one pound lost,” she says.

Christman also stresses discussing any questions you may have regarding ideal hydration levels with your health care provider, because there are certain medical conditions that warrant fluid restrictions.

Great Tips to Staying Hydrated

If you’re living a busy life, even simple tasks–like staying hydrated–can be difficult. So here are seven easy ways to keep your juices flowing.

1. Fruits and vegetables are great sources of water. Be sure to eat these daily, not only to stay hydrated, but to maintain optimal health.

2. Keep a large water bottle handy to encourage you to drink water wherever and whenever.

3. Have a glass of water before each meal.

4. After each trip to the restroom, drink a glass of water to replenish your fluids.

5. Set reminders on your phone, watch, or email to drink every hour.

6. Track your intake of fluids to make sure you get enough daily.

7. Add a slice of lemon, lime and/or basil to your water to give it some flavor without adding any extra calories.