High intensity sports can drain the body of essential nutrients including water, important electrolytes (sodium and potassium) and deplete blood sugar and glycogen stores which are important for fueling the body during exercise. Knowing what to drink to properly replace these nutrients can help athletes optimize their performance.

Adequate hydration is important even in sedentary individuals, but it is a critical component to high level functioning athletes who put significant demands on their bodies. There is a reason why water is one of the essential nutrients of the body.

Water provides a number of important functions in the body including transporting essential nutrients throughout the body, diffusing oxygen in the lungs, absorbing heat to help regulate the body’s temperature, lubricating the joints to reduce unwanted friction, and providing structure and form to the body. All of these functions are critical to the health of an individual.

While the average individual consumes approximately 41 ounces of water daily, an athlete may consume five or six times that amount when exercising (McArdle, W.D., Katch, F., & Katch, V., 2006). Proper fluid intake keeps the body performing at its optimal level.

However, while water intake is sufficient to meet the needs of an individual for their daily activities, athletes need drinks with additional electrolytes (sodium) to help the body absorb the base water in the fluid. Sodium is beneficial because it helps to reduce urine output while sustaining the drive to drink.

While some athletes have been encouraged to take salt tablets to help increase their sodium levels, care must also be taken when ingesting salt tablets to increase sodium levels as they have the potential for gastrointestinal problems (McArdle, W.D., Katch, F., & Katch, V., 2006).

It is also recommended that athletes ingest a fluid drink with a low percentage of carbohydrates so that the blood sugar levels and glycogen stores of the body can be replenished. Athletes need to also understand that ingesting fluids with high concentrations of carbohydrates (sodas, juices) can actually slow down the rate of water absorption. Watch Video on Hydration in Sports

The body naturally loses fluids in a number of ways including in urine, through sweating, and through water vapor during exhalation. However, when an athlete exercises, the amount of water lost from the body increases significantly due to the increase in water loss from sweating. The loss is even greater if an athlete wears heavy equipment such as in football or when the athlete exercises in hot weather.

A football player in full gear competing in hot weather can easily lose five to 10 pounds of water weight a day placing the athlete at risk for dehydration and heat illness. As the athlete’s water content decreases, his or her ability to perform will begin to deteriorate with the athlete at risk for muscle cramps, nausea, dizziness, light-headedness, and fainting.

The consequences of dehydration are correlated to the severity of dehydration. The ranges of physiological consequences exist on a continuum with muscle cramps (mildest form) on the far left and heat stroke (most severe and possibly fatal form) on the far right.

Muscle cramping is usually the first sign that an athlete will experience with mild dehydration. The most common muscles that cramp are the calf muscles and thigh muscles including the hamstring muscle group. Muscle cramping usually occurs towards the end of a competition when the athlete’s fluid levels have significantly decreased and their muscles are fatigued.

If hydration levels are not restored to normal levels during this phase, the athlete may progress to heat exhaustion and then finally to heat stroke. In heat stroke, the athlete’s temperature regulating system will completely shut down and the athlete may experience bright red skin, no sweating, disorientation, seizures, coma and a core body temperature of 105 degrees or more. This is a medical emergency and requires immediate medical attention.

The important point to understand is that heat illnesses are completely preventable as long as the athlete stays hydrated DURING AND AFTER sports activities.

When the body is depleted of fluids, the athlete needs a quick source of fluids that enhance water absorption while replacing the electrolytes and blood glucose lost from the activity. While water is a good drink for athletes performing mild to moderate activities, athletes performing high intensity activities need fluids that will help the body to absorb water.

According to McArdle, W.D., Katch, F., & Katch, V. (2006), there are five qualities to an ideal rehydration drink and they are the following:

1. Good taste
2. Rapid absorption
3. Causes little or no gastrointestinal distress
4. Helps maintain extracellular fluid volume
5. Offers potential to enhance exercise performance

In recent years there has been an explosion of sports drinks on the market. While many proclaim to help performance, there are some guidelines that athletes should follow in selecting their rehydration drinks.

The ideal hydrating drink for athletes has a 5% - 8% carbohydrate-electrolyte level. This level has been shown to help temperature regulation and fluid balance while also assisting the body to maintain its energy metabolism and energy stores. The drink’s carbohydrate percentage can easily be calculated by dividing its carbohydrate content (in grams) by the fluid volume (in milliliters) and multiplying by 100.

For example, SOBE Lifewater Pomegranate Cherry drink has a carbohydrate level of 42 grams per a total of 591 milliliters (20 oz bottle). When divided, this equals .07 or 7%. This drink falls within the recommended range for carbohydrates. This drink also has a sodium content of 55mg to enhance the absorption of the water within the drink.

Original Gatorade is another drink that falls within the recommended ranges of carbohydrate-electrolyte levels with a 6% carbohydrate level and 110mg of sodium.

In higher temperatures, the carbohydrate levels can actually be reduced to less than 5% to enhance the water absorption of the drink. Drinks can easily be diluted to reduce the carbohydrate levels by just adding water.

Out of good intentions, many drinks may show up in the locker room at half-time that may actually hurt the athlete’s performance and increase the athlete’s risk of heat illness. One of the more popularly donated drinks at games is soda.

While the sugar content in soda does vary between brands, the average content is somewhere around 40+ grams making the carbohydrate percentage in the drink somewhere between 10 and 11 percent or higher. The disadvantage of these drinks is that it takes longer for the body to absorb the water within the drink because of the high sugar content.

Soda beverages also tend to have caffeine which is a known diuretic. Diuretics assist the body in removing fluids so adding a diuretic is counterproductive when trying to hydrate athletes. Read more about Caffeine and athletes.

Juice is another beverage that may be donated out of good intentions because of the health benefits of the vitamins within the juice. However, athletes need to know that the carbohydrate percentage in juices is between 12% - 15%. This level of carbohydrates within the drink will significantly slow down the body’s ability to absorb the water from the juice.

The other disadvantage of these drinks is that they tend to have low to trace amounts of sodium and so they will not enhance the body’s ability to absorb the water content within the drinks.

Care must also be taken in the use of energy drinks during competitions. The same rules can apply to these drinks as to the soda and juice. The athlete should look carefully at the carbohydrate, sodium, and caffeine content of the drinks before using them. Many of these drinks are high in both sugar and caffeine which are both counterproductive to hydrating athletes.

Having a sound knowledge of the importance of adequate hydration along with knowing the recommended carbohydrate and electrolyte levels will help the athlete in selecting drinks that will help his/her body perform at the highest levels.

If you have any concerns or questions about your nutritional needs, seek the consultation of a local sports nutritionist for appropriate care. To locate a top sports nutritionist in your area, please visit our Find a Sports Nutritionist Near You section.