14 DAY TRIAL // After a long run in the heat, the only thing you can think about is a bottle of cold water that you'd just drink at once.
Water is refreshing, but is it healthy in this case?
W. Larry Kenney, Penn State professor of physiology and kinesiology, says a sports drink would be more appropriate. "Sports drinks have extra ingredients that are not found in water. Electrolytes such as sodium and potassium are the most important additives, and carbohydrates are a close second. Electrolytes are physiologically important substances that regulate the body's hydration, and nerve and muscle function," said Kenney.
While sweating during exercising, you do not lose just water, but also ions (also called electrolytes). "The amount of fluid lost varies tremendously between individuals and is dependent upon exercise intensity and duration, temperature and humidity, and the type of clothing one wears. Heavy sweaters can lose up to three pounds per hour," said Kenney. "There is another reason for adding electrolytes like sodium. Think of a bartender who offers free pretzels and peanuts: he wants you to drink more. The salt in sports drinks helps to maintain thirst. If you drink plain water until you no longer feel thirsty, you've most likely not replenished all lost fluids."
The carbohydrates in sports drinks are aimed to provide energy during long exercise sessions, and they are beneficial not only for marathon runners and triathlon athletes. "We tested the effect of sports drinks on youth basketball players and found that the carbohydrate-containing beverage improved sprinting and delayed fatigue," he explained. "Glucose, sucrose and fructose yield the same results when the body breaks them down," he said.
But fructose from corn syrup can result harmful to some people's stomach and sugar should be consumed with caution. Sugar is also aimed to improve the taste of the drink. "The goal of sports drink manufacturers is to determine what tastes best when you're hot and sweaty."
Kenney explained that sports drinks are not necessary for all sports. "Water is fine for low-intensity and non-endurance athletes whose priority is not carbohydrate replacement. But for those extreme athletes who sustain physical activity for more than four hours at a time, the sodium in sports drinks can be helpful in warding off a condition called "hyponatremia." Also referred to as water intoxication and much rarer than dehydration or heat exhaustion, "hyponatremia occurs when excess water dilutes the sodium in the body," explained Kenney. "The prototype person at risk is an endurance or ultra-endurance athlete -- typically someone who is smaller and slower than the average," he continued.
The shortage of sodium in the organism induces nausea, vomiting and swelling of hands and feet, cardiac or neurological complications (like swelled neurons). That's why he advocates for sports drinks over water in more than 45 minutes of high-intense sport activity. "It's important to drink before, during and after activity. You should drink one hour before a workout to give your kidneys time to dispose of excess fluid. And if possible, you should consume every 15 to 20 minutes during a workout. Most importantly, drink enough afterwards to replace all losses within the first two hours."