Hydration for young athletes
UNMH emergency room doctors say dehydration is a common problem they see in the summer months. High temperatures, low humidity and high winds in the Southwest all contribute to fluid losses, which are often not recognized by participants who are focused on participating in their activity.
Credit: John Arnold

It gets hot living in New Mexico. Exercising or competing outside can be challenging, especially during the summer. One of the biggest challenges is maintaining optimal levels of water and electrolytes in your body. Fortunately, with good planning it's easy to stay hydrated.

How do you get athletes to hydrate?

Many athletes understand the need to stay hydrated, especially in the New Mexico heat. Some of these athletes are self-aware and will simply consume enough water to stay hydrated. For other athletes, getting them to actually consume fluids can be the challenge. For younger athletes, adding flavoring to water has been proven to help (grape flavoring was used in one research program). Also, you can chill the water. One research project showed that athletes of all ages will drink more if water is cooled by just 10 degrees. Another research project has shown that having sports drinks available can increase the percentage of athletes that will hydrate. Even if the athletes don’t need the nutrition and electrolytes provided by sports drinks, athletes tend to grab one more often and stay hydrated.

If you are having a practice on a hot day, the best way the help your athletes to stay hydrated is to provide a cooler full of ice and sports drinks.

"Dehydration is a common problem among athletes and recreational exercisers during the summer months in New Mexico," says Dr. Jenna White, an assistant professor at the UNM Health Sciences Center, and an avid runner. "The high temperatures, low humidity and often high winds all contribute to fluid losses, which are often not recognized by participants who are focused on participating in their activity. If these losses become substantial, not only will athletic performance suffer, but serious illness can sometimes result."

White also says that while sports drinks do include electrolyte replacement, and the fact that their good taste does prompt athletes to drink more of them by volume than they would just plain water, they also contain a lot of sugar. The sugar content of many of these products approaches that of soda. High sugar content can lead to gastrointestinal distress if consumed rapidly on a hot day, and many athletes (young or otherwise) aren't exercising intensely enough or for long enough to need the caloric intake that these beverages provide. 

Water
Water helps to regulate your body’s temperature, moves nutrients for energy and lubricates your joints. If you are not properly hydrated, your body has to work harder to manage these systems efficiently and you will not be able to perform at your highest level physically or mentally. Losing just 2 percent of your body weight in water can cause fatigue, cramps, dizziness or more serious symptoms.  

Athletes lose water in several ways, including through respiration, which increases during exercise, and via sweating and urination, according to Dr. Ann Gateley, a UNM sports medicine doctor. A number of factors determine how much you sweat, including the temperature amd humidity, how hard you are exercising, how much sleep you have had, your overall fitness level and how big your body is.

The first step in detemining how much water you need to consume, is to gauge how much you are losing through sweating. A basic calculation to determine water loss from sweat:

Body weight (in pounds) before exercise, without shoes 
+ fluid intake (convert from oz to lbs: 16 oz = 1 lb)
- post-event body weight without shoes
= total sweat loss not replaced.

Example: A 180 lb. athlete drinks 24 oz of water during two hours of practice
and weighs 176.75 lb. post-practice.
He/she did not replace 3.75 lbs. of fluids over 2 hours.
To determine the sweat rate, take 3.75 lbs. x 16 oz = 52 oz. un-replaced fluid,
add in the 24 oz. consumed to get a total of 76 oz.
Divided by 2 hours, yields an hourly hydration rate of 38 oz. per hour.
This athlete should be hydrating at a rate of 38 oz. every hour.

A one-pound loss is equal to losing 16 ounces of fluid. Divide your total water loss by the number of hours you practiced to determine approximately how much water you should be consuming per hour. If you wait until you are thirsty, you are already dehydrated. An American Academy of Pediatrics study showed that youth athletes often don’t “feel” thirsty, until they are already 5 percent dehydrated. Hydrate before you think you need to. It is better to stick to your hydration plan and stay hydrated than to play “catch-up” after dehydration sets in.

Electrolytes

If you are sweating from exercise, you are depleting your body's electrolytes, which affects your thinking ability and performance. Electrolytes are minerals found primarily in your blood and other fluids that carry an electric charge and are critical to the proper functioning of the different systems in your body. Common electrolytes include sodium, chloride, calcium, magnesium and potassium.

Sodium and chloride are probably the two most important electrolytes, as all cells depend on them to bring nutrients inside the cell and to remove waste. Nerve conduction, necessary for thinking and activating muscles, also relies heavily on sodium. Potassium is the primary electrolyte found within your body’s cells and works closely with sodium and chloride to maintain fluid balance and conduct nerve impulses and promote cellular homeostasis. Calcium, better known for its role in promoting bone strength, is another electrolyte that is important to athletes, as it aids in muscle contraction, inter- and intracellular communication and plays a key role in glycogen metabolism. Muscle cramps can be caused or made worse by low potassium or calcium levels, Gateley says, but fortunately this is quite rare. Magnesium is the fifth of the major electrolytes that can impact performance, as it also aids in proper transmission of nerve impulses, muscular contraction and energy production.

Depleting any of these five major electrolytes can lead to weakness, confusion, muscle cramps and nausea. All of these minerals are depleted with exercise. A strong nutritional plan will account for electrolytes as well as carbohydrates, proteins and fat. There are many ways to pre-load beforehand or replace electrolytes during or after exercise or competition. A number of supplements and sports drinks can do this effectively. A handful of salted peanuts can be just as effective post-event.

"New Mexico is often hot," Gateley says. "For athletes in practice and competition, proper hydration is the cheapest and easiest way to maintain performance."

Do Your Muscles Cramp Often?

A 2005 study of NCAA Division I players found that players who tend to cramp have higher sweat loss levels and higher levels of sodium loss than athletes who don’t. One common myth in athletics is that cramps are often due to a loss of potassium, however, the amount of potassium loss through sweat is likely too low to cause sudden-onset muscle cramps. If you tend to cramp, understanding and actively managing your own hydration and electrolyte level -- particularly sodium levels -- can keep you performing at your highest level.