The Physiology of Exercise Part 3: The Importance of Potassium

-Dawn Wolfe

Welcome back to our ongoing series on the physiology of exercise! As we said in our first installment, the purpose of this series is to help all of us better understand the ways that exercise affects our bodies. This information comes in handy to help us promote our overall health and as a set of tools we can use to optimize our bodies' performance whether we are training for athletic events or “just” training to become as fit as possible.

 With that in mind, today we're going to talk about one of the most important minerals in the human body – potassium. According to the University of Maryland Medical Center's online overview,

Potassium is… very important… for the proper function of all cells, tissues, and organs in the human body. It is also an electrolyte, a substance that conducts electricity in the body, along with sodium, chloride, calcium, and magnesium. Potassium is crucial to heart function and plays a key role in skeletal and smooth muscle contraction, making it important for normal digestive and muscular function.

In other words, we need to have a sufficient level of potassium in our systems to be able to exercise – and to insure that our digestive systems and our hearts work properly. Fortunately, it's fairly easy to ingest enough potassium just from eating a healthy, varied diet. (For a list of potassium-rich foods, which include meats, fruits, and vegetables, click here for a chart provided by Colorado State University)

However, while it's fairly easy to get all of the potassium we need from our diets, two of the factors that can lead to a depletion of potassium are a diet that's heavy in sodium (as in, the typical American diet) and the kind of heavy sweating that accompanies intensive exercise, particularly during the summer when we exercise outdoors in the heat.

If you've ever had an intense muscle cramp during or after exercise, in fact, your cramp may have been the result of your body “leaking” too much potassium in your sweat. And when it comes to the typical American high-sodium diet, there is evidence that an imbalance between the levels of potassium and sodium in our bodies can lead to high blood pressure.

How can you make sure you're getting enough – but not too much – potassium, especially during the critical summer season?

• Eat a balanced diet that's high in potassium-rich foods. Don't count on sports drinks like Gatorade to keep your potassium levels on track; most experts say that energy drinks aren't the best way to get the balanced nutrients we need.
  
  
• Limit your consumption of sodium. This doesn't mean going totally salt-free, but it does mean being mindful about how much table salt you're taking in on a daily basis. A little salt on your eggs in the morning is fine – a serving of fast-food French fries, though, is almost certainly too much.
  
  
• Other health conditions, like stomach flus that lead to diarrhea, kidney issues, and unmanaged diabetes can also lead to troubles with potassium levels. If you have a health condition that may be affecting your potassium, or you otherwise suspect that you may be dealing with the effects of either too little or too much potassium in your system, consult your health care professional.