How important are fluids? Fluid replacement is probably the most important
nutritional concern for athletes. Approximately 60% of your body weight is
water. As you exercise, fluid is lost through your skin as sweat and through
your lungs when you breathe. If this fluid is not replaced at regular intervals
during exercise, you can become dehydrated. When you are dehydrated, you have a
smaller volume of blood circulating through your body. Consequently, the amount
of blood your heart pumps with each beat decreases and your exercising muscles
do not receive enough oxygen from your blood. Soon exhaustion sets in and your
athletic performance suffers. If you have lost as little as 2% of your body
weight due to dehydration, it can adversely affect your athletic performance.
For example, if you are a 150-pound athlete and you lose 3 pounds during a
workout, your performance will start to suffer unless you replace the fluid you
have lost. Proper fluid replacement is the key to preventing dehydration and
reducing the risk of heat injury during training and competition. How can I
prevent dehydration? The best way to prevent dehydration is to maintain body
fluid levels by drinking plenty of fluids before, during, and after a workout or
race. Often athletes are not aware that they are losing body fluid or that their
performance is being impacted by dehydration. If you are not sure how much fluid
to drink, you can monitor your hydration using one of these methods. 1. Weight:
Weigh yourself before practice and again after practice. For every pound you
lose during the workout you will need to drink 2 cups of fluid to rehydrate your
body. 2. Urine color: Check the color of your urine. If it is a dark gold color
like apple juice, you are dehydrated. If you are well hydrated, the color of
your urine will look like pale lemonade. Thirst is not an accurate indicator of
how much fluid you have lost. If you wait until you are thirsty to replenish
body fluids, then you are already dehydrated. Most people do not become thirsty
until they have lost more than 2% of their body weight. And if you only drink
enough to quench your thirst, you may still be dehydrated. Keep a water bottle
available when working out and drink as often as you want, ideally every 15 to
30 minutes. High school and junior high school athletes can bring a water bottle
to school and drink between classes and during breaks so they show up at
workouts hydrated. What about sport drinks? Researchers have found that sports
drinks containing between 6% and 8% carbohydrate (sugars) are absorbed into the
body as rapidly as water and can provide energy to working muscles that water
cannot. This extra energy can delay fatigue and possibly improve performance,
particularly if the sport lasts longer than 1 hour. If you drink a sports drink,
you can maintain your blood sugar level even when the sugar stored in your
muscles (glycogen) is running low. This allows your body to continue to produce
energy at a high rate. Drinks containing less than 5% carbohydrate do not
provide enough energy to improve your performance. So, athletes who dilute
sports drink are most likely not getting enough energy from their drink to
maintain a good blood sugar level. Drinking beverages that exceed a 10%
carbohydrate level (most soda pop and some fruit juices) often have negative
side effects such as abdominal cramps, nausea, and diarrhea and can hurt your
performance. What does the sodium in sports drinks do? Sodium is an electrolyte
needed to help maintain proper fluid balance in your body. Sodium helps your
body absorb and retain more water. Researchers have found that the fluid from an
8-ounce serving of a sports drink with 6% carbohydrates (sugars) and about 110
mg of sodium absorbs into your body faster than plain water. Some parents,
coaches, and athletes are concerned that sports drinks may contain too much
sodium. However, most sports drinks are actually low in sodium. An 8-ounce
serving of Gatorade has a sodium content similar to a cup of 2% milk. Most
Americans do get too much sodium, but usually from eating convenience-type
foods, not from sports drinks. What are guidelines for fluid replacement? ·
Drink a sports drink containing 6% to 8% carbohydrate to help give you more
energy during intense training and long workouts. To figure out the percentage
of carbohydrate in your drink use the following formula: {Grams of
carbohydrate/serving}/ {240 g/ serving} X 100 = % of carbohydrate in drink For
example, 240 ml (a 1cup serving) of a drink with 24 grams of carbohydrate per
serving would have a 10% carbohydrate concentration. Almost all drinks have the
grams of carbohydrate per serving and the volume in ml somewhere on the
container. · Drink a beverage that contains a small amount of sodium and other
electrolytes (like potassium and chloride). · Find a beverage that tastes good.
Something cold and sweet is easier to drink. · Drink 10 to 16 ounces of cold
fluid about 15 to 30 minutes before workouts. Drinking a sports drink with a 6%
to 8% carbohydrate level is useful to help build up energy stores in your
muscles, particularly if the workout will last longer than 1 hour. · Drink 4 to
8 ounces of cold fluid during exercise at 10 to 15 minute intervals. · Start
drinking early in your workout because you will not feel thirsty until you have
already lost 2% of your body weight; by that time your performance may have
begun to decline. · Avoid carbonated drinks, which can cause gastrointestinal
distress and may decrease the fluid volume. · Avoid beverages containing
caffeine and alcohol due to their diuretic effect. · Practice drinking fluids
while you train. If you have never used a sports drink don't start during a meet
or on race day. Use a trial-and-error approach until you find the drink that
works for you.

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