Thankfully, it's not all mysterious. You already know you won't get far without replenishing the triumvirate of endurance nutrition: calories, fluids and electrolytes. The calorie part is easy—fuel equals energy and energy equals performance.
The same goes for fluids—dehydration won't just slow you down, it's also dangerous. But what about electrolytes? You've been told you need them, and you may even know they help keep body chemistry in balance. But how critical are they to performance?
Very. Electrolytes aren't just essential for optimal performance; they're critical for any kind of performance. The truth is, you should be just as concerned about replenishing them as you are with replacing lost fluid.
What Are Electrolytes?
Electrolytes are minerals that, when dissolved in water, break into small, electrically charged particles called ions. Present wherever there's water in your body (think blood, cells and cell surroundings), electrolytes regulate your body's fluids, helping to maintain a healthy blood pH balance, and creating the electrical impulses essential to all aspects of physical activity -- from basic cell function to complex neuromuscular interactions needed for athletic performance.
More Than Salt
Many people know sodium and chloride are among the body's most important electrolytes (both help "excite" nerves and muscles), but don't think dousing your food with table salt (sodium chloride) is the only key to proper electrolyte replacement.
Consider these other key electrolytes:
If you eat a balanced diet you're probably consuming adequate quantities of electrolytes for normal human function. When consumed, electrolytes separate into positively and negatively charged ions in the water inside or surrounding each cell and in the bloodstream.
The water then serves as a conductor, allowing ions to move across membranes and carry fluid, nutrients and waste. In the process they trigger nerve impulses and muscle function and allow ions in the blood to neutralize lactic acid as well as other acids dumped into the bloodstream as waste.
As long as your hydration and electrolyte levels stay in balance, you enjoy normal physical function. However, add exercise to the equation and that balance begins to shift, first by increasing the concentration of electrolytes in your body and then, over time, depleting them—a circumstance that can hinder athletic performance and in extreme cases can lead to serious illness.