Did you know that 60 to 70 percent of the human body is made up of water? And that losing as little as 2 percent of your body weight via sweat can undermine your athletic performance?
We’ve all seen it during major sporting events—athletes dropping out with muscle cramps or fatigue. Dehydration is serious and can lead to a drop in blood volume, which causes muscle cramps, dizziness, fatigue and heat illness.
Many athletes focus on nutrition to energize their workouts and help muscles recover, but in the process overlook fluids. Water is the critical foundation upon which all other nutrients perform. However, how and how much to hydrate varies by person and training conditions. You have to be aware of your own unique needs and environment.
Hydration levels are affected by temperature, intensity of exercise, humidity and type of clothing. The impact of a long run on a cool morning is much different than the impact of one in the full sun on a hot summer afternoon. Intense exercise in hot and humid conditions increases the amount of fluid your body loses and also increases the amount you need to drink to stay hydrated.
“When it comes to hydration, there is not a one-size-fits-all solution,” explains Steve Hertzler, PhD, RD, chief scientific officer with Abbott’s EAS Sports Nutrition business. “Be sensible. Know your needs. There are risks with both dehydration and overhydration, also called . When deciding how much your need to drink, take into consideration your climate, your level of acclimation to those conditions and overall sweat loss.”
When we sweat to stay cool, we lose water and electrolytes (minerals that include sodium and chloride). Of these electrolytes, sodium is the most important. Besides replacing the losses, sodium plays an important role by:
When exercising in very hot conditions and/or at high intensities for 60 minutes or longer, you might consider a sports drink, which helps replenish stores of sodium and other electrolytes.
“Remember not to overlook the fluids you are getting from other sources,” says Hertzler. “Fruit and veggies are 80 to 90 percent water and provide helpful hydration. Tea, coffee and other caffeinated beverages also count just as juice and milk do.”