Water - The Athlete's Most Important Nutrient

This week’s article is on the importance of hydration. Between training (which requires more hydration – you do sweat when you swim) and the weather warming up, I thought this would be appropriate. Your swimmer is encouraged to bring water to practice! Have a bottle sitting on the deck next to their lane is a great idea. I encourage my AG3 swimmers to drink their water when I am telling them their next set of the workout. This goes for swimmers AND parents. We both know that our swimmers cannot make it to practice if you were unable to bring them and they appreciate the work you do (as do I)! So please, have some water on hand throughout the day! And it does not have to be water specifically – one of the reasons why I love this hand out is how it breaks down some of our common foods and drinks with the percentage of water in them!

WATER: The Athlete’s Most Important Nutrient

Forget about every other question that you have about nutrition until you’ve figured out how to stay hydrated. Being smart about water intake can separate good performance from great performance. You are mostly water. In fact, if you took the water out of a 180-pound lean body, there would be about 55 pounds left. Because your muscles, your brain, your blood and sweat are mostly water, your body doesn’t work like it should when it doesn’t have enough water. You don’t think as clearly, your lose endurance and your heart works harder. When you’re severely dehydrated, sweating stops and your body overheats. The result-fatigue, weakness, dizziness, and collapse, or worse. In fact, every year, deaths in young healthy athletes are linked to severe dehydration.

Sweat It Out

Sometimes you don’t even see sweat, like when you swim. But you sweat whenever your body heats up from working out. Sweat is your body’s cooling system. Evaporation of sweat from your skin cools you down. When you sweat, you lose water from your body and that water must be replaced. Replacing the water takes a plan.

Don’t Rely on Thirst

You might be thinking, “What’s the big deal? Won’t drinking when I’m thirsty guarantee that I’m hydrated?” Surprisingly, no. During exercise, for reasons not totally understood, humans don’t drink enough to prevent dehydration. You need to drink before you’re thirsty and keep drinking after you no longer feel thirsty.

Drink It In

Forget about the old rule of drinking 8 glasses per day. You probably need more than that on most days. Counting how many glasses you drink is only one way of keeping track of what you need. A better way of making sure you’re hydrated is to check your body weight before and after practice. For accuracy, weigh in minimal clothing if there’s privacy, and afterwards, change out of the sweaty clothing before you weigh. The weight lost during practice or competition is not fat, it’s water loss. One pint of water weighs one pound. To replace the water, drink one pint of fluid for every pound you lost. (One pint = 16 ounces = 500 ml = ½ liter).

It is critical to replace the water loss as quickly as possible. Before your next workout, your weight should be back up to normal. If you can’t check your weight, pay attention to your body for signs of dehydration. Your mouth should not be dry. Your urine should be lemon-colored most of the time. More than one episode of dark yellow urine is a warning sign that you don’t have much reserve. (Exception: Vitamin supplements can turn your urine yellow-orange, even if you are hydrated.) Loss of appetite, stomachaches, and muscle cramps can be other warning signals of dehydration. When? Drink before, during and after working out. Drink a pint or so of fluid a few hours before exercise. This will help make sure you are hydrated and give you enough time to urinate if you need to beforehand.

Keep drinking during exercise. If you are sweating, your body needs a constant supply. Drinking fluids after workouts is extremely important. Even when drinking fluids during a workout, many athletes become dehydrated. Athletes working out in the heat for several hours can lose 10 pounds. That's more than a gallon of water.

What Should I Drink?

Your body needs water. But remember water comes in all sizes, shapes and colors. Milk is 90% water. Juice and most soft drinks are 89% water, sport drinks are 94% water, and even pizza is 50% water. And it all counts. Nearly everything that passes your lips provides water for your body, and in fact, research shows that most hydration happens at meals from the combination of food and beverages.

Research also shows that we tend to drink more if the fluid is flavored and if a variety of fluids are available.

Keys to Hydration When you have figured out how to stay hydrated, especially when you sweat heavily, you have accomplished the single most important performance-enhancing aspect of nutrition. Water is your most important nutrient.

Water Content of Common Foods and Drinks

Item…………………………………………………………………………Water content, approximate
Diet soft drinks, tea, coffee............................................................... 99%
Sport drinks....................................................................................... 94%Milk.................................................................................................... 90%Soup................................................................................................... 90%
Soft drinks, soda pop, juice............................................................... 89%Yogurt................................................................................................ 80%Corn................................................................................................... 76%
Baked potato..................................................................................... 74%
Cooked rice........................................................................................ 73%
Cooked pasta..................................................................................... 66%Taco................................................................................................... 59%Chicken.............................................................................................. 54%
Ground beef....................................................................................... 53%Pizza................................................................................................... 50%

Prepared by the U.S. Olympic Committee Sports Medicine Division and the International Center for Sports Nutrition.

©2006 U.S. Olympic Committee