Take a deep dive into water’s partner-in-crime.

Electrolytes, a term you’ve likely heard tossed around in athletic circles when discussing hydration and sweating – but what exactly are they, and why are they crucial for endurance athletes? Today we are going to dive into the basics for athletes and if you are looking for a deeper dive into hydration check out Sweaty Season: The Basics of Hydration from Keely Henninger.

What Are Electrolytes?

Electrolytes is a catch-all term for particles that carry an electric charge – in nutrition it specifically refers to essential minerals found in your body fluids, including blood and sweat. The primary electrolytes include sodium, potassium, calcium, magnesium, chloride, bicarbonate, and phosphate. These minerals play vital roles in maintaining various bodily functions.

Importance of Electrolytes for Hydration and Performance

• Fluid Balance: Electrolytes help regulate the balance of fluids inside and outside of your cells (osmosis), ensuring that your body remains properly hydrated. Sodium and chloride are particularly important for fluid retention and preventing dehydration. 

• Muscle Function: Calcium, potassium, magnesium and other electrolytes are essential for muscle contraction and relaxation. A deficiency can sometimes cause muscle cramps, weakness, and even spasms.

• Nerve Function: Electrolytes are critical for transmitting nerve signals throughout your body. This ensures that your muscles and organs function correctly, which is vital during high-intensity exercise.

• pH Levels: Electrolytes help regulate the pH level of your blood, keeping within a narrow range necessary for optimal bodily function.

Should You Take Electrolytes?

As a runner, especially when training and racing over an hour, as well as in warmer temperatures, maintaining electrolyte balance is crucial for performance and safety.

Sweat and Electrolyte Loss: When you sweat, you lose not just water but also electrolytes, particularly sodium. The more intense and longer the exercise, as well as the hotter the environment, the more you sweat, and the greater your electrolyte loss. 

Risks of Imbalance: An imbalance, either too low or too high, can lead to issues like frequent urination, dehydration, hyponatremia (low sodium levels), muscle cramps, fatigue, and decreased performance. In severe cases, it can be life-threatening. 

A 2022 review titled “Exercise-Associated Hyponatremia in Marathon Runners”, suggested that exercise-associated hyponatremia is more common in smaller female athletes and in hotter temperatures. You can combat this by preloading with electrolytes ahead of long efforts, as well as consuming sodium and carbohydrates during exercise, rather than solely plain water.

Electrolyte Supplementation

To combat these losses, runners turn to electrolyte supplements. These can come in various forms, including drinks, powders, tablets, and gels. They help replenish the lost minerals and keep you hydrated.

Our friends over at The Feed, sponsor of the Freetrail and Trail Society podcasts, have a huge variety of different electrolyte products. Here are a few popular picks to get you started:

• Precision Fuel and Hydration Tablets
• Gnarly Nutrition Hydrate
• Skratch Labs Hydration Sport Mix
• LMNT
• Tailwind Nutrition Rapid Hydration
• Nuun Sport Hydration
• Science in Sport GO Electrolyte Drink Mix
• Science in Sport Hydro Tablets

Predictably, the answer to “when” and “how much” is, “it depends”. Not only are everyone’s sweat rates and electrolyte losses individual, but they vary for a multitude of external factors: temperature, heat, wind, hydration status, and more. Generally speaking the average amount of electrolyte loss during an hour of exercise is 800mg of sodium, 195mg of potassium, 20mg of calcium and 10mg of magnesium, and we should aim to replace at least half of that loss as runs go over the one-hour mark. This isn’t us giving you giving you the go-ahead to slam as much salt as possible, in fact consuming too much salt without enough fluids can cause much dreaded GI distress as water is drawn out of your cells and back into your intestines (osmosis at work again!). That said, here are some general guidelines around timing:

Before Exercise: If you’re starting a race, longer run, or simply training in warm conditions, preloading with electrolytes the night before and/or morning-of can help. 

During Exercise: Consuming electrolytes may be beneficial to minimize dehydration, unpleasant GI symptoms, headaches, dizziness, fatigue, nausea, cramping, and more, all of which decrease performance.

After Exercise: Replenishing lost electrolytes post-run aids in recovery and prevents dehydration.

Practical In-Run Tips

• Listen to Your Body: Pay attention to signs of electrolyte imbalance like excessive thirst, cramping, dizziness, and fatigue.

• Hydrate Wisely: Combine water with electrolyte solutions, especially during long or intense workouts. Over-drinking plain water can be just as dangerous as under-drinking: when the body is low on electrolytes, less water is retained by your body, no matter how much you’re consuming. This can result in frequent urination, dehydration, and hyponatremia – a life-threatening condition that occurs when blood sodium levels drop too low.

• Balance Your Diet: Include electrolyte-rich foods in your diet such as bananas (potassium), dairy products (calcium), nuts (magnesium), and salty snacks (sodium). Don’t be afraid to salt your food, especially around training and racing.

Bottom line – electrolytes are essential for hydration, muscle function, and overall performance, and maintaining the right balance of these minerals can make a significant difference in performance and recovery. Incorporating electrolyte strategies into your training and race plans to ensure you stay strong, hydrated, and at your best.

References

Klingert, M., Nikolaidis, P. T., Weiss, K., Thuany, M., Chlíbková, D., & Knechtle, B. (2022). Exercise-associated hyponatremia in marathon runners. Journal of Clinical Medicine, 11(22), 6775. https://doi.org/10.3390/jcm11226775

Tiller, N. B., Roberts, J. D., Beasley, L., Chapman, S., Pinto, J. M., Smith, L., Wiffin, M., Russell, M., Sparks, S. A., Duckworth, L., O’Hara, J., Sutton, L., Antonio, J., Willoughby, D. S., Tarpey, M. D., Smith-Ryan, A. E., Ormsbee, M. J., Astorino, T. A., Kreider, R. B., McGinnis, G. R., … Bannock, L. (2019). International Society of Sports Nutrition Position Stand: nutritional considerations for single-stage ultra-marathon training and racing. Journal of the International Society of Sports Nutrition, 16(1), 50. https://doi.org/10.1186/s12970-019-0312-9