So you're gearing up for another race. You've planned your workouts in minute detail, and you're sticking to your program like your life depends on it. All you need now is a performance-boosting nutrition strategy.
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.
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.
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:
- Calcium - aids muscle contraction
- Magnesium - aids healthy cell function
- Potassium - helps regulate pH balance
- Phosphate - helps regulate pH balance
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.
And for most endurance athletes, therein lies the rub: If you're already trying to re-hydrate and take in fuel for energy, how do you work electrolytes into the equation?
First, it helps to understand that when we sweat we lose electrolytes -- mainly sodium -- as well as water. But because we lose water faster than we lose electrolytes, it's not critical to replace lost minerals during shorter (less than one hour) workouts.
During shorter workouts the body's electrolyte concentration actually increases, according to Joel Mitchell, chair of Texas Christian University's department of kinesiology. Mitchell says the kidneys then act to filter out any "extra" electrolytes to correct the imbalance.
However, longer workouts can empty your body of large amounts of sodium and other important electrolytes. When electrolyte levels drop too low, severe loss of neuromuscular function can incur along with increased blood acidity (fewer electrolytes are available to neutralize the lactic acid your muscles are producing). In essence, your body begins shutting down.
It's important to replace fluids as well as electrolytes even if you don't feel thirsty, explains Leslie Bonci, director of sports nutrition for the University of Pennsylvania Center for Sports Medicine and a member of the Gatorade Sports Science Institute's Sports Nutrition Board. This is especially true in colder weather when you may not notice sweat or fluid depletion as quickly.
Luckily, replenishing lost electrolytes isn't difficult, and because electrolyte balance is tied to hydration (remember, electrolytes need water to do their job), sports drinks are often recommended as the most efficient form of replenishment, although sports gels may also do the trick.
"Sports drinks are designed to provide adequate amounts of key electrolytes, and they also deliver the added benefit of providing carbs for energy and water to supplement hydration," says Bonci, who recommends looking for drinks that deliver key minerals like sodium and chloride, the two electrolytes we lose most through sweat.
Sports drinks also help take the guesswork out of deciding how much of each electrolyte you need since they're calibrated to return average amounts of electrolytes.
But just like with pre-race rituals and training approaches, there's an element of personal preference when it comes to electrolyte replacement. So try different products until you find the ones you like best.
Bonci advises, "If you're a 'salty sweater' (your sweat stings, tastes salty or leaves a white residue on skin or clothing), or if your workouts or races are extending well beyond the two-hour mark, you may need more sodium and chloride than a sports drink alone can supply.
In this case, experiment with energy gels (carbs and electrolytes) or electrolyte capsules or tablets in addition to your sports drink, especially if you're training for major endurance events such as a half Ironman, Ironman or ultramarathon.
For less extreme distances, however, Bonci says athletes will do fine using a sports drink and possibly including higher sodium items like tomato juice, soups, baked beans, pickles and pretzels in their diet in the days leading up to an extended workout or race.
The typical athlete needs to consume a minimum of 20 to 40 fluid ounces per hour, and you should make sure you're using a sports drink that contains at least 250 mg of sodium per 20 ounces (100 mg per 8 ounces) in activities lasting more than an hour, advises Bonci.
These drinks will also contain the other main electrolytes, like chloride and potassium, in the right amounts. If you're doing an especially long workout (more than two hours) or you sweat a lot of salt, look for sports drinks that supply 500 mg of sodium per 20 ounces. You should replace lost electrolytes at a rate of 250 to 500 mg per hour if you hydrate at the recommended rate.
Likewise, electrolyte capsules offer similar ratios of electrolyte to fluid, while gels offer more concentrated amounts but need to be taken with water. If you're unsure about your electrolyte replenishment needs, especially if you're training at a higher endurance level for the first time, consult a sports nutritionist for guidance.