Hydration

General Information

 What is it?

• Water is a one of the most important things for the human body. It makes up about 60 to 70% of our weight. Water bathes our cells and organs and carries minerals to all parts of the body. It also helps get rid of wastes. We need water and other liquids every day to stay in good health. We also need a good liquid balance in order to exercise.

• When you exercise your blood moves through your body faster to give it the nutrients it needs and to cool your body down. As you perspire sodium (salt) and other minerals, such as potassium, leave your body in your perspiration. The more you exercise, the better your body adapts. It learns how to hold onto minerals so it loses less sodium and potassium in sweat over time.

 

 Proper Hydration

 Oh the looks I got when I showed up to practice years ago with my hydration pack.  I thought my coach was going to have heart failure.   I refused to take it off.   It was a special practice to say the least.  You can live without food.  You can not live without water.  I surely wasn't!  Your body is made mostly of water.  Through proper hydration, your body delivers nutrients, disposes of waste, cools your core temperature etc.  Yeah, you've heard it all before.  You know all about heat exhaustion and heat stroke.   But do you know that when you do not have enough fluid in your body, your body starts to shut down.  Your heart rate goes up, which makes you burn through fuel faster, and makes you work a lot harder.  Your cells start to constrict which makes it so fuel can not get to the muscles. Your core temperature rises.  Your muscles start to cramp up.   Everything goes very bad, very fast.  All because your coach told you 10 years ago: "don't drink in the boat." Get with the times.  If you want to perform like an athlete, eat and drink like one.

You're body loses a lot of salt and electrolytes on the water.   Make sure you are replacing them as well.   

So, how much water?   Start drinking when you wake up.  The old 32oz a day thing does not apply for endurance athletes.   You lose a lot when you sweat.  A good indicator is to weigh yourself before you paddle.  Weigh yourself after.  See how much fluid you lost.  Then drink until you are back at that weight.  Drink until you pee clearly.  Continually sip at your water while you are paddling.  The hydration pack works best for me.  It has a directional tube that I can mold and bend up to my face so it is always there.  I never have to stop paddling.   I can drink without missing a beat.  I usually have a back up bottle of water on the back on my canoe in case I need more, or if something goes wrong.  I snapped the tube off one time and lost all my water.  I had 7 miles left to go and no water.   Not a fun time for me.   I was a salty dehydrated wreck by the time I was done.  Again, every body is different.  Experiment and find the right fuel for you.  You'll be glad you did.

 

 Fluid Overview

 Of all the physiological factors that can cause early fatigue during exercise, dehydration is arguably the most important. Dehydration is a common occurrence, even during exercise in the cold. Dehydration decreases performance, impairs cardiovascular function that can impair physical performance, and pose serious health problems.

Athletes can lose a large amount of fluid when exercising. An athlete can become dehydrated in as little as 30 minutes.

Dehydration occurs when fluid (sweat) loss exceeds 1% of body weight (800 ml in the case of an 80-kg male). Work capacity and temperature control can be impaired with a loss of as little as 2% of body weight and can cause a 5-10% drop in performance. A 1/10th-temperature change can decrease performance. 
During any form of exercise, working muscles produces heat, and body temperature rises. Getting rid of this heat requires fluid evaporation from the skin (sweating) which cools the body. When fluid evaporates from the skin the body therefore losses valuable water (as high as 1-2 quarts/hour) during heavy exercise. When the athlete fails to ingest enough fluid and dehydration becomes sufficiently severe, sweating decreases in an attempt to conserve body water. As a result, blood thickens, heart rate increases and body temperature rises and you get fatigue, headache, nausea, chills, stomach discomfort and increasing the chance of heat cramps, exhaustion, or stroke.

Recent research illustrates that maintaining normal or near hydration during exercise maintains cardiovascular and thermoregulatory responses and improves exercise performance. It is always the athlete’s best interest to prevent unnecessary increases in core temp that will ultimately lead to premature fatigue. 
As you exercise, be alert for these conditions. They'll increase your loss of fluid through sweat, which could make your body become dehydrated faster.

Temperature: The higher the temperature, the greater your sweat losses. 
Intensity: The harder you work out, the greater your sweat losses. 
Body size: The larger the athlete, the greater the sweat losses. Males generally sweat more than females. 
Duration: The longer the workout, the greater your fluid losses. 
Fitness: Well-trained athletes sweat more. And they start sweating at a lower body temperature. Why? The function of sweating is to cool the body. The well-trained athlete cools his or her body more efficiently than an untrained person.

Most active people have experienced dehydration and probably haven’t been aware of it. Exercise blunts the thirst mechanism and cannot rely on thirst as an indicator of dehydration. Providing adequate fluid intake before, during and after exercise can prevent dehydration. Fluid replacement practices should be designed to match fluid intake and sweat loss. This approach will require sports competitors to ingest more fluid, often more that they are accustomed to drinking.

The rate of fluid replacement should match rate of sweating (at least 80%)

Each pound of weight loss corresponds to 450 ml (15 oz) of dehydration (8 oz = 1 cup)

Plain, cool water (5° to 10°C; 40° to 50°F) is an effective fluid replacement, and it is the most readily available and least costly alternative. Drink plain water before or during activities lasting 60 minutes or less.

Electrolytes (sodium, potassium, chloride, and magnesium) are lost in sweat, but the loss of water is considerably greater. However, in sport or training that requires more than 1 hour of continuous effort, a carbohydrate-electrolyte solution should be provided to improve performance.

Guidelines for proper hydration: 
Learn about dangers/disadvantages of dehydration 
Become aware of sweat losses (weigh before and after exercise) 
Drink to a plan 
Drink early 
Make fluid available 
Practice during training

 

 Sports Drinks

     Water is the easiest sports drink to get and it is the cheapest. But, some people who exercise feel that sports drinks are worth the extra cost.

o     Following are some of the reasons why sports drinks are better at helping you reach your fitness goals.

§      Keep you in good liquid balance by supplying water.

§      Supply carbohydrates to keep your glucose (blood sugar) level high enough. They also help prevent large losses of glycogen (stored sugar).

§      Allow you to keep up your pace for longer than you would without the extra carbohydrates.

§      Help prevent large losses of sodium and potassium during long activities over 60-90 minutes. This is even more important for activities at high altitude and those done when it is very hot.

§      Allow you to absorb water better because of the amount of sugar and sodium in the drink.

o     The amount of carbohydrates in a sports drink should be 4 to 8% in order for your body to absorb (soak it up) the best. Divide the grams of carbohydrate per serving by the serving size of your sports drink in order to figure this percent. Then multiply this number by 100 to get the percent of carbohydrates. The other way to figure this is to have a drink that has 40 to 80 calories in 8 oz (240 mL).

o     An athlete loses about 920 milligrams (mg) of sodium and 117 mg of potassium for every liter of fluid lost from sweat. Most sports drinks contain 40-110 mg sodium and    25-100 mg potassium per liter. One liter of sweat equals a little over 2 pounds of fluid loss. Most people can replace lost sodium and potassium by eating a balanced diet before and after workouts. Sports drinks may be needed during hard, long workouts lasting over 1 to 2 hours per day. Sports drinks help replace the larger amounts of sodium and potassium lost during this kind of exercise.

o     You can make your own sports drinks at home by using one of the following recipes.

§      Orange juice diluted with water with a pinch of salt added to every liter.

§      Grapefruit juice or lemonade diluted with water with a pinch of salt added per liter.

§      Glucose polymer powders from the store, mixed with water as listed on the package.

§      Defizzed soda pop diluted with water (Not high in sodium or potassium.)

§      Caffeine-free tea with honey (Not high in sodium or potassium.)

 

 Drinking liquid for sports competition or long workouts.

 Even if you are able to drink liquid during workouts, it cannot replace all of the water weight you lose. Your stomach can only handle about 4 to 8 oz of liquid at a time without getting cramps or nausea (upset stomach). This is why you should drink plenty the day before and the morning of the event.

The day before a big event or long workout: Drink 2 to 4 extra glasses of liquids in addition to the 8 to 10 you normally drink. This would be a total of 10 to 14 glasses that day. Drink enough liquid so that you urinate every 2 to 4 hours that day.

•     The day of the event:

    Drink 16 to 20 oz of liquid two hours before the event or workout. o 
    Drink another 8 to 16 oz of liquid 10 minutes before the event or workout. o 
    Drink 4 to 8 ounces, or the most you can handle, every 15 to 20 minutes during a long workout    or activity.

•     After the event,

drink enough to replace the liquid you lost. Drink 16 oz, or two 8 oz glasses, for every pound of body weight you lose during the event. 

What kinds of liquids should I drink?

The best kinds of liquid to drink are water, juice, sports drinks, or other liquids that have no caffeine or alcohol. Caffeine and alcohol act as diuretics which means they cause you to urinate more than usual. This can cause you to become dehydrated (d-hi-dra-ted) or not have enough water in your body. Even if you take caffeine as a workout aid, avoid it during the 24 hours before a big event or race to prevent losing liquids. Following are other ways to get more liquids.

Fruit smoothies.
Popsickles. 
Soda pop.
Lemonade or limeade. 
Decaffeinated coffee or tea. 
Herbal teas.

• The best temperature for liquids that you drink during exercise is between 35 and 40 degrees F. Cool liquids cause fewer cramps than cold ones for most people and are better at keeping your body temperature down.

 

  Liquid Serving Sizes

•      1 oz is about 30 mL.
•     1/2 cup is about 120 mL or 4 oz.
•     1 cup is about 240 mL or 8 oz.
•     1-1/2 cups is about 360 mL.   This is 12 ounces or the size of a soda pop can.
•     1 pint is 480 mL. This is 16 oz or 2 cups.
•     1 liter (L) is about the size of 1 quart. This is 960 mL or 32 oz

 

 How much is enough?

 How can I tell if I'm drinking enough liquids?

•     You have been drinking enough water if you urinate at least 1-1/2 quarts per day, and your urine is light yellow or amber color. Darker urine, or going less often, are signs that you need to drink more liquid.

How can I tell that I'm not getting enough liquids?

•     An athlete can get hyponatremia (low sodium in the blood) as they perspire and if they drink   too much water without getting enough salt. Symptoms include confusion, headache, nausea, vomiting, muscle weakness, and in severe cases, seizures. You can prevent this by eating a balanced diet and eating a salty food every few days. You may crave salt or salty foods after a day-long activity. This may be a sign that you need to eat a serving of salty food, to replace what was lost in the workout. Check with your doctor before doing this if you have high blood pressure.
•     Each person needs different amounts of liquid during exercise. Try different kinds of drinks and find out what is best for your body. It may take a few months to figure out what the right liquids are for you and when the best times are to drink for your type of exercise.

 

 Figuring out how much to drink 

•      Liquids are measured in ounces (oz). The easiest way to know out how much you need to drink is to weigh yourself just before and after a workout. The weight you lose during exercise is the amount of water you need to drink afterward. If you lose 1 pound, you need to drink two 8 oz glasses, or 1 pint (16 oz) of water or other liquids. If you lose 2 pounds, you need to drink twice that much, or four 8 oz glasses of water (32 oz) in the two hours after exercise.
•     Another way to figure out what how much liquids you need is to figure it out based on how much you eat. For every 1000 calories you eat each day you need 1 liter (L), or about one quart (32 oz) of liquid. Ask your dietitian to help you figure out the number of calories you eat per day if you use this method.
•     For workouts that are 60-90 minutes or more, drink liquids while you are exercising. Drink at least half the amount of liquid you expect to lose during the exercise itself.   With time you, can learn how to figure this out by weighing yourself before and after a workout. Be even more careful when it is hot out in order to prevent getting overheated.