It’s got electrolytes! …So?

Based on my continued Precision Nutrition education…

If you’ve ever seen Idiocracy, you know that in the future, people appreciate electrolytes a lot more than they do today. Sure, we have Gatorade. But they have Brawndo.

While these people clearly don’t know much, they obviously know that electrolytes are important (even if they don’t know why). If only they could figure out how to use the internet to find this post, where we explain the basics behind the brawn.

What are electrolytes? Do you even know?

Electrolytes are ionized forms of certain mineral in our diets. When dissolved in water, sodium, calcium, potassium, chloride, and magnesium each carry an electrical charge, thanks to the gain or loss of an electron. Sometimes called salts, electrolytes are present in both intracellular and extracellular (vascular and interstitial) fluids. In order to maintain optimal physiological function, we need to maintain a correct electrolyte balance.

Brawndo’s got what plants crave

Turns out it doesn’t. But it definitely has what humans crave. Without normal electrolyte concentrations, a number of physical functions can be disrupted; if they are not corrected, this can even lead to death. That’s not cool! On the other hand, normal electrolyte concentrations mean normal physical function. Different ions play different roles, but overall, the functions of electrolytes include:

  • Co-factors: Working with enzymes, they can help speed up chemical reactions in the body.
  • Cell excitability: Excitable cells (nerve and muscle cells) don’t want to party. They want to transmit your neural signals and contract your muscles. But they need a little boost. Thanks, sodium, potassium, and calcium, for helping out.
  • Cell non-excitability: Non-excitable cells, or excitable cells in their resting state, still experience a difference in membrane potential. Intercellular fluid has a slightly negative electrical charge due to higher levels of potassium. Extracellular fluid has a slightly positive charge, thanks to higher sodium levels.
  • Water and molecule movement: Nature dislikes an imbalance, but sometimes it’s helpful. The difference in electrical charge between intra- and extracellular fluids help promote the movement of water and other molecules into and out of cells, interstitial compartments, and capillaries via osmosis.
  • Hormone and neurotransmitters: Calcium is involved with the secretion and operation of some hormones and neurotransmitters. It’s also involved in every muscular contraction, and a host of other functions.
  • Acid-base balance: Phosphorous and other electrolytes and proteins help maintain the body’s acid-base balance, or pH. The body has a very narrow pH range within which it can survive, so we definitely want to keep on top of this.

There are several ways in which we lose electrolytes, including sweat and urine. Generally, both of these are hypotonic, meaning that they contain more water than solutes (including proteins, electrolytes, and other molecules). There is still some loss of electrolytes though, and depending on the circumstances, they can be quite substantial.

Sodium is one of the primary solutes lost in sweat, though some people are more “salty sweaters” than others. Based on high sodium concentrations in sweat (and low concentrations of other electrolytes) it’s thought that a whole-body sodium deficit is primarily responsible for electrolyte-deficient muscle cramping, particularly if the sweat rate itself is high. Urinary electrolyte excretion, on the other hand, has a lot to do with dietary intake. If electrolyte consumption is high, excretion is also likely to be high, and vice versa.

So if we’re losing them, we should replace them, right?

This is not what I had in mind...

Electrolyte replacement can come in the form of food or beverages. During times of non-exercise, or for short and moderate intensity and duration exercise, normal dietary intake will be enough to support your efforts, assuming normal sweat rates, sweat sodium content, dietary sodium intake, and temperate environments.  On the other hand, you might need to top up your salts if your training sessions are of the longer endurance variety. You might also need a hand with moderate duration and intensity exercise if sweat rates or sweat sodium content is high (though you’ll only know the content if you get it tested). Bear in mind that hot environments are more likely to lead to high sweat rates.

Brawndo will help you win at exercise

But only if you need it. If you don’t need electrolyte replacement, sports drinks will not increase your performance. In fact, if you are trying to lose weight, stick with water during your exercise session – you don’t need the extra calories. If you are going harder or longer though (1 hour+), you might get some benefit from taking in some electrolytes during and after your session. Research suggests that the best form of both fluid and electrolyte replacement is a low-carbohydrate drink that also contains electrolytes. The drink should be relatively dilute (6-8% carbs and salts during training, and 10-12% carbs and salts for post-training replacement) to allow quick gastic emptying and absorption, as well as preventing any GI distress. This equates to roughly 30-40g carbohydrate and electrolyte per 500ml water (providing 6% and 8% respectively). Gatorade and Powerade both fit this category, and if a higher concentration is needed for post-exercise recovery, 0.5-1 tsp of sodium can also be added.

Again, I’d like to stress that for most of us, dietary intakes will easily satisfy our electrolyte needs. Pounding bottles of whatever sports drink you prefer for your 30 minute treadmill jog is going to do more harm than good, since it’s pretty easy to take in more calories than you’re actually burning off. Stick with water – it’s got a much more normal color, too.

On a somewhat unrelated note, if you haven’t seen Idiocracy, do the world a favor: check it out and then tell all your friends too as well. I’m hoping it might scare a few of us straight!

References
1. Berardi, J and Andrews, R. 2010. The Essentials of Sport and Exercise Nutrition. Precision Nutrition, Inc.
2. Bergeron, MF. 2008 Muscle Cramps During Exercise – Is It Fatigue or Electrolyte Deficit?” Curr Sports Med Rep 7, s50-s55.
3. Gee, DL. n.d. Fluid and Electrolyte Replacement in Athletes. Viewed 14 August, 2011. <http://www.cwu.edu/~geed/446/fluids.ppt&gt;
4. Bowman Jr., DO. 2000. Electrolyte Balance. Viewed 13 August, 2011. <http://science.kennesaw.edu/~bodavis/LECT03.PDF&gt;
5. Wakefield, R. 2009. Fluid, Electrolyte, and pH Balance. Viewed 13 August, 2011. <http://dtc.pima.edu/blc/2028thed/011/011LectureTopics/011Lectoutline%5B7th8th%5D.pdf&gt;
Advertisements

One response to “It’s got electrolytes! …So?

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s