Salt and Electrolytes

Salt And Electrolyte Loss For Athletes

Sweat is made up of mostly water and sodium. Sodium is the electrolyte responsible for controlling the total amount of water in your body. This balance is critically important for things like hydration, nerve impulses, muscle function, and pH level.  An electrolyte imbalance, whether too much or too little, can cause major health issues.

When you lose sweat (water and salt) and replace it with water (no salt) you dilute the sodium in your bloodstream.  If you don’t replace water and sodium you risk suffering from hyponatremia, an electrolyte disorder where there is too little sodium in the body.  Hyponatremia is the most common electrolyte disorder in the United States, but most of us have never heard of it.

Here’s what you need to know:

1.    Sweat: When you sweat you lose fluid and electrolytes, all kinds of electrolytes…sodium in particular.

2.    Hydration: Staying hydrated is important, but drinking water is not enough, your body needs you to replenish the sodium lost through sweat too.

3.    Sodium: Your body needs sodium to survive; it plays a key role in muscle and nerve function and is responsible for maintaining your body’s fluid levels.

4.    Balance: The most important thing to remember about hydration and electrolytes is balance.  Your body usually does a pretty good job of maintaining this balance on it’s own, but when you introduce an ultra-endurance triathlon and extreme heat to the mix, things can get a little more complicated.

5.    Sweat Rate: Calculating your sweat rate is an easy way to determine sweat-related sodium loss.  By calculating your sweat rate you can determine approximately how much sodium you are losing per hour through sweat. Keep in mind, your sodium loss may be higher in extreme heat.

Calculating Sweat Rate:

1.    Weigh yourself nude/dry before your workout.

2.    Weigh yourself nude/dry after your workout.

3.    Multiply the amount of weight you lost by both 16 to get your net sweat loss in ounces.

4.    Add the ounces you drank (both water and sports drink) to get your gross sweat loss.

5.    Divide by the hours of your workout. This gives you how many ounces of sweat you lose per hour.

Symptoms of hyponatremia can include:

•    Headache

•    Confusion

•    Fatigue

•    Hallucinations

•    Muscle spasms

•    Nausea

•    Muscle cramps

•    Disorientation

•    Slurred speech

•    Confusion

•    Inappropriate behavior

•    Severe hyponatremia is a true medical emergency.

Here’s how to prevent hyponatremia:

•     Drink frequently to attempt to stay hydrated.
•     Balance rehydration by increasing your salt intake to maintain the proper balance of sodium in your blood.  Sodium is important for rehydrating because it acts like the sponge that keeps fluids in your body.
•     During a long, hot race, it is recommended to aim for a total sodium intake of approximately 1 gram per hour (½ tsp. of salt is about 1 gram of sodium).
•     During training, heat acclimatization, and for several days leading up to a big race, it’s generally a good idea to increase salt intake by 10 – 25 grams per day.
•     These amounts obviously vary by individual.  Calculating your sweat rate and monitoring yourself during training are the best ways to make sure you develop the plan that’s right for you.
•     Sodium is also important for recovery.  Adding sea salt to your favorite healthy foods following an intense workout can help to restore sodium lost through sweat.

It is best if you strive to get your sodium from salty foods — as opposed to salt tablets.  Salty foods stimulate thirst causing you to drink water to balance your salt intake.  It is possible to ingest too much salt with tablets and much less likely if you stick with salty foods.