Athletes, Sweat, and Why You Need Electrolytes | BridgeAthletic

Posted by Megan Fischer-Colbrie on May 7, 2015 11:52:03 AM

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sweatyathleteAthletes sweat a lot. Every day. Their high metabolic rate causes them to sweat more than an average person, so they not only sweat a lot because they work out so frequently, but also because they sweat a sizeable amount each time they do. Unfortunately, athletes who don’t use electrolytes to help replace lost fluid may be under-hydrating during and post-workout. Paying attention to your hydration is a simple and easy way to maximize your performance, so let’s dive in.


In the midst of a tough workout, it’s easy to forget to hydrate. Dehydration can ruin an otherwise solid workout, and if left unchecked, can reduce your training capacity over the course of a whole season. In a slightly dehydrated state, as in 1-2% reduction in body weight through fluid loss, your perceived exertion goes up (how much work you feel you’re putting in), performance goes down, and emotional state becomes more variable (prone to being irritable, moody, fatigued, etc). Moreover, your post-workout recovery slows down when your fluid volume is at a suboptimal level for quick delivery of nutrients and oxygen to working muscle tissues and removal of waste products from the bloodstream. Basically, everything gets a little harder when you’re dehydrated.


Why are Electrolytes So Important for Elite Athletes? 

Electrolytes are positively or negatively charged ions that conduct electrical activity to perform various functions within the body. Electrolytes must be present in proper concentrations to maintain fluid balance, muscle contraction and neural activity—all essential to high performance and basic daily functions. The kidneys control electrolyte balance by excreting or conserving them. Water is drawn to local concentrations of electrolytes, so it follows wherever they go. When you sweat, you’re losing electrolytes primarily in the form of sodium (Na+) and chloride (Cl-), so when you start to replace lost fluids, you should replace the electrolytes as well. Potassium (K+), Magnesium (Mg2+) and Calcium (Ca2+) are electrolytes also lost through sweat, albeit in lower amounts than sodium and chloride. 


How Much Electrolytes Do I Lose?

The presence of electrolytes in your sweat is why sweat tastes salty. Some athletes have saltier sweat than others due to simple genetic differences, diet, sweat rate, and heat acclimatization. Athletes who feel dizzy, lightheaded, or experience muscular cramping post-workout may be salty sweaters experiencing an electrolyte imbalance. If you only drink water to rehydrate, you could be diluting your internal electrolyte concentration and throwing your body further off balance. While the human body is good at regulating itself, elite training is strenuous and long enough that you must actively pump electrolytes in to support the rehydration process.


When Should I Replace Electrolytes?

Before Workout: If you are a “salty sweater” then you might consider drinking an electrolyte beverage or having a salty snack prior to a heavy workout (> 60 – 90 minutes) or one that is performed in hot temperatures. 

During Workout: Electrolyte products that contain sodium and carbohydrates are ideal during exercise. The sodium replaces lost electrolytes and helps the body utilize carbohydrates. Many sports drinks contain sugar in such high concentrations that athletes don't feel comfortable drinking them mid-workout. You can 1) look for drinks that are lower in sugar (yet still avoid artificial sweeteners), 2) alternate between the sports drink and water during practice, or 3) choose a powdered electrolyte so you can control how concentrated your drink is. 

Post Workout: It is easier to retain water in the body with the intake of salt, because water naturally follows those molecules. Ingesting salty foods or a sports drink can help you rehydrate faster than by drinking water alone.


Recommended Amount of Fluids and Electrolytes?

This depends on the type and duration of exercise…

Within 60-90 minutes of exercise, athletes can lose around 1-2% body weight in the form of fluids. Your weight (say 150 lbs) multiplied by this percentage is the amount of fluid you should try to drink as a replacement (150lbs x 0.01 to 0.02 = 1.5 to 3 lbs bodyweight loss, or 24 to 48 fl oz). Given a hot day or a high sweat rate, this number can increase. 


For exercise duration under 2 hours, a beverage containing 60-120 mg sodium and 15-45 mg potassium per 8-oz serving will be effective for electrolyte replacement. Check the label to find your desired ratio of electrolyte to carbohydrate.


Extreme distance athletes like marathon (or ultra-marathon) runners and Ironman triathletes may need a much higher concentration of electrolytes delivered to their system with fewer carbohydrates and minimal liquid, so as to avoid stomach pains during their long races. If you’re in this category or are exercising longer than 2 hours, shoot for anywhere between 180-250 mg sodium and 10-100 mg potassium per 8-oz serving.


Remember that the sodium, rather than potassium, plays the primary role in electrolyte replacement and is thus a more important factor when deciding which electrolyte product to purchase.



Electrolytes come in tablets, powders, gels, chews, blended sports drinks, table salt, food, and more. For most elite athletes, sports drinks and powders mixed with water are common ways to ingest electrolytes. Endurance athletes may prefer electrolyte tablets or chews to maximize salt intake while minimizing liquid intake. Whatever your method of choice, start using electrolytes during and post-workout to see how it affects your training. Over time you can calibrate your electrolyte intake to customize it for your performance needs!


Find related articles on hydration and performance on our nutrition page at BridgeAthletic!

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2. Sawka, Young, Cardarette, et al. 1985 



Topics: Nutrition