Potassium and Endurance

Potassium and Endurance

Ever wonder why bananas are handed out at marathons? Central to muscle and nerve function, potassium is a make-or-break nutrient for endurance athletes. Here's what you need to know about potassium and endurance.


  • Potassium is an essential micronutrient that plays a key role in many of the body's functions. 
  • Endurance athletes should be considering potassium as part of their hydration strategy. 
  • Three ways to add potassium to your diet include: supplements, beverages, and foods. 

Role of Potassium in Nutrition

Potassium is an essential micronutrient that plays a key role in many of the body’s functions—including muscle contraction, nerve signaling, and the regulation of blood pressure. As part of the cell membrane’s “sodium-potassium pump,” it helps ensure the proper amount of water stays inside our cells, acting as a counterbalance to sodium, which is concentrated outside the cells.

For potassium, the body requires a serum concentration of about 3.6 to 5.0 mmol/L for these systems to function well.1 If potassium drops too low, hypokalemia symptoms can set in, which include fatigue and muscle weakness in the early stages, and shallow breathing and irregular heartbeat as it becomes more severe.2

Download our Potassium Guide to learn about fortifying with this under consumed nutrient.  

Potassium: A Nutrient Guide

Potassium: A Nutrient Guide

Download our eGuide today! 

Why Potassium Is So Important in Endurance

While we all need potassium, it becomes even more critical for endurance athletes. Not only are they losing a lot of potassium through sweating, but their performance can easily become impacted by the slowdown in nerve and muscle action that comes from potassium loss. Low potassium has also been linked to muscle cramps.

Studies of marathon runners show that runners can have even higher concentrations of potassium outside their cells than inside after exercising for a long time. Restoring intracellular potassium is essential to maintaining optimum fluid balance and avoiding unpleasant low potassium symptoms that also put a drag on performance. Endurance athletes should be considering potassium as part of their hydration strategy—pre-workout, intra-workout, and post-workout.

two men biking

Ways to Add Potassium to Your Diet

Fortunately, there are a variety of ways to add more potassium to the diet. For non-athletes, consuming naturally rich food and beverage sources of potassium may suffice if it’s done on a daily basis. For endurance athletes, supplements and functional products can help bridge any gaps.


Potassium supplements for sports nutrition range from ready-to-mix beverage powders for hydration to electrolyte gels, chews, and capsules. For dry formats, adequate hydration will still be important due to the close relationship between potassium and water.


For ready-to-drink options, sports drinks with electrolytes are a convenient way to get potassium while on the go. Another popular option among endurance athletes, particularly for post-workout replenishment, is low-fat or nonfat milk.


When looking at foods for potassium, dried fruits such as apricots and raisins come in at the top—even ahead of bananas. Starchy vegetables like potatoes and squash, as well as certain legumes like lentils and kidney beans, are important sources of potassium, in addition to fortified products like bars.

dried fruit

Winning the Long Game

As consumers become increasingly knowledgeable about sports performance ingredients that can give them an edge, food, beverage, and supplement brands are challenged with staying one step ahead to create the best products to meet these needs. 

Our custom premix solutions can help you succeed with sports nutrition consumers—by including just the right blend of our standard-form or functionally optimized nutrients and functional ingredients they’re looking for. Collaborate with us on your next sports nutrition product.

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1-2. NIH Office of Dietary Supplements, Potassium Fact Sheet for Health Professionals, updated June 2, 2022

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