Jul | 10
Running Tips

Sweating the Small Stuff: Electrolytes

why are electrolytes important to runners, getting electrolytes back after a workout, drinking electrolytes after track, cross country and importance of electrolytes

By Nuun Guest Blogger Jesse Kropelnicki of The Core Diet.

Even if you have never had a “cramping problem” in the past, neglecting electrolytes in training and racing could be compromising your results. Just like you wouldn’t wait until you were dehydrated to drink fluids, waiting until that first “cramp” is a signal from your body that your performance has been suffering for quite some time. Electrolytes play a crucial role in muscle function, adequate hydration status and digestion fluids during racing.

What is an electrolyte?

In medical or scientific terms, an electrolyte is “any compound that, in solution or in molten form, conducts electricity and is decomposed (electrolyzed) by it. It is an ionizable substance in solution.”

In other words, it’s a term for minerals that, when dissolved in water, break into positive or negative electrically-charged ions (anions or cations).

What are the functions of electrolytes?

why are electrolytes important to runners, getting electrolytes back after a workout, drinking electrolytes after track, cross country and importance of electrolytes

Do you take electrolyte supplements before or after your run?

These ions carry electrical energy necessary for many functions in the human body, and optimal athletic performance requires adequate (and a consistent) supply of electrolytes. These ions move across membranes carrying fluids, nutrients and water. They aid in a number of processes that are important to an athlete:

  • Regulation of body fluids
  • Muscle contraction (including the heart)
  • Transmission of nerve impulses

However, repeated days of moderate or severe sweating can result in such substantial electrolyte loss, particularly sodium because of its high concentration of this mineral in sweat. When electrolytes are lost too quickly, the body does not have the ability to restore them as rapidly as they were lost. In these situations, dietary mineral intake is generally not sufficient to compensate for these large losses, and supplementation is needed to replace these electrolytes in order to maintain concentrations of body fluids.

What are the major electrolytes in the body and what do they do?

  • Sodium (Na+) – regulates total amount of water in the body
  • Potassium (K+) – regulates heartbeat and muscle function
  • Magnesium (Mg2+) – aids in muscle relaxation
  • Calcium (Ca2+) – aids in muscle contraction
  • Chloride (Cl-) – helps maintain a normal balance of body fluids

How are electrolytes lost?

Electrolytes are lost through urine and sweat. Endurance athletes can lose large volumes of sweat on a daily basis, which is accompanied by a similarly large electrolyte loss.  Each athlete has different electrolyte (and fluid) needs and environmental conditions of training and racing will factor into this.

  • Average sweat rate is typically 1 – 1.5L of fluid per hour (32 – 48 oz.) and 1,000 – 1,500 mg of sodium per hour while running (a bit less when cycling).
  • Most people’s sweat contains about 500mg of sodium per 16oz. Very salty sweaters can have up to about 1,500 mg per 16 oz. of sweat.
  • Sweat rate will depend on several factors including environmental conditions (temperature, humidity), genetics and the athletic fitness of the athlete.

Side Effects of Dehydration

In most cases, muscle cramping is related to either sodium or magnesium deficiency in athletes. If a deficiency occurs, cramps, tremors and spasm can be present. It is the Core Diet’s experience that acute occurrence of cramps during racing is typically due to sodium loss, and more chronic cramping (even between activity, during swimming or while sleeping) is typically due to magnesium deficiency. Another sign of sodium related cramping is a sloshy stomach. Another electrolyte, magnesium, is key in avoiding muscle spasms. A muscle “twitch” is usually a sign of low magnesium levels. Having proper sodium balance during digestion is important to fluid absorption.

Have you ever felt tingling fingers during your racing? If you have, you probably are experiencing a potassium deficiency. Many times a simple half banana available on many race courses can fix this problem before it impacts race performance.

How to replenish electrolytes?

Electrolytes help to increase the absorption of fluids into the bloodstream, and your muscular system operates efficiently which is why the best hydration plan is one that includes these minerals. Using products such as Nuun Active Hydration (electrolyte-enhanced drink tablets) before, during, and after workouts can go a long way to replenish electrolytes and achieve your best performance.

Nuun provides great-tasting active hydration.

About Nuun

Nuun is a great tasting on-the-go hydration tablet with the electrolytes you need to hydrate and re-fuel, but none of the sugar and junk found in sugary sports drinks. Nuun is available in over 5,000 stores in the U.S. and in over 30 countries. Visit nuun.com to learn more.

About The Core Diet

Jesse Kropelnicki is an elite triathlon coach and founder of TheCoreDiet.com, a leading provider of sports nutrition. He coaches professional triathletes Caitlin Snow, Ethan Brown, and Pedro Gomes with quantitative training and nutrition protocols. Track Jesse’s coaching strategies tips on his blog at kropelnicki.com.

Jaime Windrow is a Registered Dietitian and the Nutrition Programs Director at TheCoreDiet.com. Jaime’s interest in sports nutrition began when she danced professionally for 12 years with the Radio City Rockettes, and continued when she began to race in triathlons as an elite amateur. Jamie holds a number of age-group wins and podium finishes, as well as a finish in Kona at the Ironman World Championships.

About Guest Blogger
The Brooks Blog regularly features stories from our athletes, running partners and friends who exemplify Run Happy.
    • brooksblog

      @disqus_lQr3wQadpL:disqus Glad you enjoyed the article! Sloshy stomach is when the liquid in your stomach bounces so that you can feel it “slosh” back and forth.

  1. Rafal

    Nuun is great, though as a practical issue I find it hard to take with me on my runs, since the fizziness often makes my water bottle leak. Love it as a post-run rehydrator and when it’s really humid and I’m going longer, I’ll use it before a run too.

    The other thing I LOVE for upping electrolyte intake are sodium-enhanced energy chews / gels. My faves here are Clif Margarita Shot Bloks. 50mg of sodium per chew, and since the standard dose is 3-6 per hour, that’s an 150-300mg of additional sodium per hr. If you’re a powerbar gel fiend, those have 200mg per gel pouch and I think there it’s one gel every 45 mins, so ~ 267mg of additional sodium per hr.

    Casey: a sloshy stomach is when your GI system get overwhelmed to the point where it’s not processing stuff, even liquids. It literally feels like anything you take in just sits, and if it’s liquid, sloshes around your stomach.

  2. Rafal

    Props to Jesse for being a fount of fueling and nutrition wisdom.. I’ve heard him talk and it’s surprising how many “bad behaviors” of athletes he nails and corrects / de-mystifies in his talks. Keep it up!

  3. KyleJeffreyKranz

    “In most cases, muscle cramping is related to either sodium or magnesium deficiency in athletes. ”

    Ah…no it’s not. It’s related to racing too high above your current fitness level.

    I’ve done ultras without any electrolyte supplementation and without any cramps. Yet I’ll occasionally get calf cramps after 5k-10k races. Due to electrolytes? I think not. Simply due to the fact that I rarely spend that long of a distance at that fast of a pace at once, during training.

    I’ve never taken electrolyte supplementation, but get plenty from my daily diet.

    A good and recent read would be Waterlogged, by Tim Noakes.

  4. Adam St.Pierre, MS

    Muscle cramps are NOT 100% related to electrolyte loss or dehydration, as evidenced that they regularly happen in shorter events (5km/10km) where there is no change in either. Cramps are a result of trying to maintain too high a workload for too long a duration, as stated below. Waterlogged is a great read and shows that there is enough evidence against the dehydration-electrolyte imbalance-muscle cramp theory to warrant further research. Nuun is clearly trying to sell more product with this article. Passing it off as fact.

    With regard to sloshy stomach, when the solute content in the stomach is high, the body will take water from the blood into the stomach to aid in digestion. If you take in more solute (electrolytes, sugars, etc.) to attempt to quell a sloshy stomach, you will actually create a sloshier stomach.

  5. Jessica Benson

    I’ve been training for a half marathon the last few months, I’m up to 10.5 miles now, but today at about mile 6 my quads started hurting, it progressively just got worse, to where I’m was barely shuffling to finish the 10.5, and my slowest time ever. I ate a great carb dinner last night, I’m always very hydrated, I stretch, I had 12oz water on my run and two cliff energy shots. But even hours later I feel like its everything I can do to just not pass out, my legs have never been this sore and I am utterly exhausted. I did 10 mi. Last Sunday and did not feel nearly this drained. Could this be electrolyte related?

    • brooksblog

      @disqus_xDfGi9q8qU:disqus Hi Jessica- You’re going to do great in your half! Good luck!

      Sorry to hear your run didn’t go as great as you hoped. Replenish and rehydrate today and stick to your training plan. Everyone has off days, but if you continue to feel this way during and after your runs, it’s definitely worth asking your doctor for their advice.

      Run Happy!

Leave a Reply

You must be logged in to post a comment.