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Do You Need to Supplement with Electrolytes During Endurance Exercise?

“Back in the day, nobody took electrolytes tablets in the long course endurance events. It is all just marketing hype.”running-gopher

This is a comment I heard recently and it made me think a bit. Hmm, is this true?

First let’s define the primary physiological ions of electrolytes:

  • sodium
  • potassium
  • calcium
  • magnesium
  • chloride
  • hydrogen phosphate
  • hydrogen carbonate

What purpose do they serve?

Here are a few quotes from wiki to shed some light.

“All known higher lifeforms require a subtle and complex electrolyte balance between the intracellular and extracellular milieu. In particular, the maintenance of precise osmotic gradients of electrolytes is important. Such gradients affect and regulate the hydration of the body, blood pH, and are critical for nerve and muscle function. Various mechanisms exist in living species that keep the concentrations of different electrolytes under tight control.”

“For example, muscle contraction is dependent upon the presence of calcium (Ca2+), sodium (Na+), and potassium (K+). Without sufficient levels of these key electrolytes, muscle weakness or severe muscle contractions may occur.”

“Serious electrolyte disturbances, such as dehydration and overhydration, may lead to cardiac and neurological complications and, unless they are rapidly resolved, will result in a medical emergency.”

These few quotes seem to show the importance electrolytes have in general body processes and endurance sports performance.

Does our body have enough internal electrolyte stores to keep our body in proper physiological balance? This is where art once again comes into play. We are similar but unique creatures. So there probably is no precise answer to this question but it would seem that the longer and more intense (heat, humidity, etc) the event the more likely electrolyte supplementation would be beneficial.

I have always supplemented during events/training longer than a couple hours. Supplementation could mean gels (with electrolytes), fluids (with electrolytes), electrolyte tablets (ex: Endurolytes), or even fruit. Ah fruit, remember this.

Old School

So how did the legends of endurance sports ever get to the finish line?

Many would take handouts of what was available on the course or use other caloric dense items. Often some sort of fruit was used as well as other home concocted fuel treats but we won’t get into those.

Let’s take a look at some of the popular items from the road and trail events and note their electrolyte content.

  • Banana (small, 90 cals) – magnesium: 27 mg, potassium: 362 mg, calcium: 5 mg
  • orange (small, 45 cals) – magnesium: 9.6 mg, potassium: 174 mg, calcium: 38.4 mg
  • pretzels (1 oz, 106 cals) – magnesium: 8.1 mg, potassium: 38.1 mg, calcium: 5 mg, sodium: 380 mg (salted)
  • Potatoes (boiled 1/2 cup, 68 cals) – magnesium: 17.2 mg, potassium: 296 mg, calcium: 3.9 mg, sodium: 3 mg
  • Raisins (1 oz, 85 cals) – magnesium: 9.8 mg, potassium: 209 mg, calcium: 14.8 mg, sodium: 3.4 mg
  • Figs (dried – 1 count, 21 cals) – magnesium: 5.6 mg, potassium: 56.1 mg, calcium: 13.4 mg, sodium: .8 mg
  • Dates (mejool – pitted, 66 cals) – magnesium: 13 mg, potassium: 167 mg, calcium: 15.4 mg, sodium: .2 mg

As you can see even the old school athletes were ingesting an assortment of electrolytes.

The difference today is that many people are using manufactured sports products which don’t contain electrolytes naturally. Some of these products may include an electrolyte mix within them or individuals will often include a electrolyte supplement pill/powder of some type such as Endurolytes during long course endurance events/training.

Yes old schooler’s may not have supplemented with electrolytes but it would seem that many consumed some in the food they ate throughout the event.

General Recommendations

Hammer Nutrition Fueling Handbook (starting on page 29) provides some athlete and science tested advice.

  • First, electrolyte needs vary widely per individual and environment.
  • Use product with full panel of electrolytes, not just sodium and potassium.
  • For their product – Start off with 1-3 Endurolytes per hour depending on individual size and adjust from their.

One Endurolyte serving contains:

  • 25 mg magnesium
  • 25 mg potassium
  • 50 mg calcium
  • 40 mg sodium (as sodium chloride)
  • 60 mg chloride (as sodium chloride)
  • a few other ingredients such as vit B-6, manganese, L-yrosine, glycine

One size does not fit all

If you participate in longer endurance events, electrolyte supplementation may be worth investigating. Also be aware of the electrolyte spectrum we have available in nature.

What has been your experience in the electrolyte wonderland?

Be active – Feel the buzz!

About the author

David Hanenburg David Hanenburg is the passionate dirt-lovin' creator of Endurance Buzz and has been playing in the endurance sports world since 2000 after knockin' the dust off of his Trek 950 hardtail thanks to a friend asking to go ride some local dirt. In 2007 he ran his first ultra on the trails and fell in love with the sport and its people. For more information on David's endurance sports journey, check out the About page.

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