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Electrolytes - Your molecular friend!

Article written by Daniel Healy.

We’ve all seen the ads, a sports star chugging back red, green or yellow fluid, sweat beading from their brow telling us: “Nothing beats (nominated brand of sports drink)” followed by a toothy grin. But what exactly are they all grinning about?

The electrolytes, they tell us, are what make sports drinks better. But what exactly are electrolytes? What do they do? And are they really that good for you? Well strap yourself in folks we’re going to look into the human cell and see exactly what sports stars are raving on about when they tells us “nothing beats sports drinks”!

So what are electrolytes?

Electrolytes are soluble molecules whose ions will conduct electrical currents.3 That’s just a fancy way of saying that electrolytes conduct energy when dissolved in liquid. To go into the mechanics of how this works requires a complex explanation so we’ll focus on what electrolytes actually do in our bodies.3

What do electrolytes do?

Think of your body’s cells as a giant fish pond. They are after all around 70% water.4 External substances can often affect the water quality of the fish pond. Pollution for example can leave the water quality unsafe for the fish endangering their livelihood. The pond requires a mechanism to cleanse this water, this is usually through a stream that keeps pumping in new water and an outlet that releases the old water, and this keeps water quality at an optimum level for our fish.4

Our cells also require a constant source of fresh water so chemical reactions that produce energy can keep occurring. Without energy we can get pretty sleepy! These chemical reactions that produce energy also have waste products that effectively “pollute” the cell.3 It’s water’s job to diffuse these products out of the cells and eventually out of the body via urination, breathing or sweating.3, 4 The only problem is that water often can’t get these waste molecules into or out of the cells without the help of electrolytes.

Sodium and Potassium - the Electrolyte traders!

Sodium and potassium are two fantastic electrolytes that effectively draw water to and from cells. They are also the two main electrolytes in a number of sports drinks. When we drink water it goes into our stomach and is then diffused through our gut lining into our bodies. Water is diffused to where it is needed throughout our extracellular fluid.3 This is simply fluid that exists between our cells. To actually get inside our cell the water must pass through our cell membrane. Think of this as a rubbery wall that only lets certain nutrients in. Problem is water will only go into our cell if there is adequate sodium inside of the cell. Sodium attracts water. Unfortunately for the cell, sodium is one nutrient that the cell membrane won’t let in. Do you see the problem? How can our cells get sodium inside the cell so the water will follow? It turns out that our cells have a mechanism that trades potassium, which is abundant in the cell, for sodium.3 The guys in the white coats call this the Sodium Potassium pump. When the sodium is allowed into the cell through this pump guess what? In goes all that yummy fresh water to keeping the cell hydrated and functioning.

When you’ve been exercising waste products build up within the cell requiring large amounts of water to transport these byproducts out of our bodies. Water is also required to hydrate the cells after the expulsion of these waste products. Thus the consumption of sports drinks containing electrolytes is commonly marketed as essential for rehydration.

So, then are sports drinks good for you?

Along with electrolytes, most sports drinks contain a lot of sugar. One 20oz bottle may even contain around the same amount of sugar as a can of coke (12oz).1 So in essence, if you’re not exercising at an intense rate for more than 40 minutes you really won’t need them.2 We get plenty of sodium in our diet, essentially through salt added to foods or present in foods without us even being aware of it. Potassium is also abundant in meat, dairy, beans, nuts, fruit and vegetables.5 So it’s unlikely for most to need to supplement these.

The Bottom line

If you’re goal is weight loss it is probably best to stay away from sports drinks. They have too much sugar and really we get plenty of sodium and potassium from our diet. If you are an athlete trying to improve performance, sports drinks may be effective particularly for sports lasting over 40 minutes however this is a discussion you should have with your sports dietician.

References

  1. Calorie King Australia, 2009. Nutritional information [Online]. Available at www.calorieking.com.au [Accessed 1st April 2009].
  2. Guy, Lisa, November 2005. Sports Drinks: the real facts [Online]. Available at http://health.ninemsn.com.au/article.aspx?id=693802 [Accessed 31st March 2009].
  3. Martini, Frederic H. et al, 2001. Fundamentals of Anatomy and Physiology. Prentice-Hall Inc., USA
  4. Roizen, Michael F., Oz, Mehmet, C., 2006. You the owner’s manual. Piatkus Books Ltd., USA.
  5. Vaughn’s Summaries (One-pagers), 2003-2004. High Potassium Foods summary. Available at http://www.vaughns-1-pagers.com/food/potassium-foods.htm [Accessed 1st April 2009].

 


Last updated 17 June 2009