NEWS for North Dakotans
Agriculture Communication, North Dakota State University
7 Morrill Hall, Fargo, ND 58105-5665

September 3, 1998

Athletic Performance Dependent Upon Fluid Intake, Nutrition

An athlete's body perspires to cool off. When humidity levels are high, the body feels hotter, produces more perspiration and in turn loses more fluid. So, fluid intake is one factor affecting an athlete's performance. Proper nutrition is another. But of the two, ignoring the body's need for fluids can produce life-threatening consequences.

"Already this season a high school football player from North Carolina has died due to severe heat exhaustion. News reports said he was a super-fit individual. A tragedy like that could just as easily happen here," says Denis "Izzy" Isrow, a professor in the health, physical education and recreation department at NDSU.

The Dallas-based National Athletic Trainers' Association of which Isrow is a member says athletes and others engaging in physical activities should drink at least 16 ounces of fluid an hour beforehand. During the activity, they should drink from 4 to 8 ounces of fluid every 15 to 20 minutes. Afterward, they should drink at least 24 ounces of fluid, or athletes should consume 16 ounces of fluid for every pound they've lost.

What kind of fluid? Water or sports drinks can be equally effective, and Bison athletes have the option of both, says Scott Woken, head athletic trainer at NDSU. The key is to keep taking on fluid. Psychologically, some may require a specific flavor or color in order to continue drinking 4 to 8 ounces of fluid every 15 or 20 minutes. On the other hand, Woken says water remains the "gold standard" for fluid replacement in many situations.

When the body perspires, it's losing more than fluid. It's also losing electrolytes, or minerals, like sodium and potassium. Sports drinks contain these compounds, as well as carbohydrates (sugar), but research conducted by The Gatorade Company indicates that more is not better. For example, the higher the concentration of carbohydrates a beverage contains, the harder it is for the body to absorb the fluid. That's why many soft drinks and fruit juices make poor fluid-replacement beverages during athletic competition or other physical activities.

"Once you feel thirsty, you already may be dehydrated," cautions Isrow. "And once you can't sweat, you've got problems because it's an indication that dehydration is close. Not being able to sweat can also be a sign of heat stroke."

To some extent, sports drink manufacturers formulate sodium, potassium and carbohydrate levels to stimulate consumption. In other words, the goal is to develop a particular taste that will entice a person to voluntarily take on more fluid, which aids the rehydration process, explains Isrow.

But beyond promoting fluid-intake, do the electrolytes and other compounds contained in sports drinks actually enhance an individual's performance? No, Isrow says. Most of the energy expended during an athletic contest or other activity will come from what a person consumed the day before.

When it comes to fueling the body with food, Isrow says routine is important. Those competing or involved in other types of strenuous physical activities should eat their meals the day before the event at normal (for them) times. If possible, they should eat their pregame or pre-event meal 3½ or 4 hours before the competition or activity.

"Athletes and everyone else should aim for a variety of foods from all five food groups," says Julie Garden-Robinson, extension food and nutrition specialist at NDSU. "But there's no need for athletes to eat extra protein. Most Americans consume twice the daily protein requirement each day.

"Remember to start each day with a good breakfast. Power up with high-carbohydrate meals that include cereals, breads and pastas. Athletes should focus on nutritious foods and eat fewer empty-calorie foods such as candy, soda pop and desserts, which provide few nutrients for the number of calories they provide. Too many sweets can cause swings in blood sugar, which can make you feel tired and decrease your performance."

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Sources: Denis Isrow (701) 231-7463 and Julie Garden-Robinson (701) 231-7187

Editor: Dean Hulse (701) 231-6136