Sodium, Potassium, and Performance: How to Actually Dial in Your Electrolyte Intake During Training

So much of the nutrition research on training focuses on macronutrients, including protein. Today, we are taking a look at micronutrients, specifically the natural electrolytes, sodium and potassium, and their role in athletic performance. 

Let’s look at: 

• What are electrolytes?
• Why athletes can lose electrolytes quickly
• Sodium and potassium for athletic performance and muscle function 
• Signs of electrolyte deficiency
• How to get electrolytes to match your training
• What to look for in electrolyte drinks + what to avoid
• Electrolyte FAQs

What Are Electrolytes, and Why Do Athletes Lose Them Faster Than Most People?

Electrolytes are mineral ions that come from foods and beverages we consume. They are essential for life, control the electrical activity of cells, support water balance and hydration throughout the body, and additional electrolyte benefits for overall health. (1) 

Electrolytes include: 

• Sodium
• Potassium
• Magnesium
• Calcium
• Chloride
• Phosphorus
• Bicarbonate

Both high and low electrolyte levels disrupt body functions, and athletes are particularly vulnerable to low electrolyte levels. Low electrolytes and dehydration can increase cardiovascular strain and decrease athletic performance. (1, 2)

For athletes, the major factor contributing to electrolyte depletion is sweating. Because of increased sweating, athletes have higher needs for water and electrolytes to sustain hydration with activity. (3)

Most people doing a typical, climate-controlled lifting session and eating a reasonably balanced diet do not require an electrolyte supplement. It becomes more useful as duration, heat, sweat rate, repeated sessions, and dietary context increase fluid and sodium losses.

Other factors that contribute to an athlete’s need for replacement (such as with an electrolyte powder) include:

• High-intensity, endurance, or ultra-endurance exercise
• Training or competing in hot weather
• Dry climate 
• Sauna use
• Specific medication use, such as diuretics
• Low carb diets (which increase electrolyte requirements)

Sodium and Athletic Performance: Why Under-Fueling Salt Is Hurting Your Training

Sodium is an ion in the extracellular fluid around cells. Along with potassium, it helps regulate fluid balance and what passes through cell membranes. It’s involved in muscle and nerve function, maintaining pH levels, and blood pressure. Regulation of sodium levels primarily happens via the kidneys, but sodium intake through beverages and foods with electrolytes also matters. (1)

The primary source of sodium in the diet is salt. While eating too much dietary salt gets a lot of attention in the medical world, athletes and particularly those participating in prolonged endurance exercise, can also develop hyponatremia, or abnormally low blood sodium levels. Exercise-associated hyponatremia most often occurs when fluid intake exceeds fluid losses, diluting the sodium in the blood, although sodium losses through sweat may also contribute. (1, 4)

Hyponatremia can lead to headaches, muscle cramps, confusion, nausea, and in severe cases, delirium. (1, 5)

Because sodium is lost through sweat, athletes with high sweat rates, salty sweat, or prolonged training may need to replace sodium along with fluids. A natural electrolyte drink can be a convenient way to support fluid and sodium replacement, but sodium intake alone cannot prevent hyponatremia if fluid intake is excessive. (6)

Potassium and Muscle Function: The Electrolyte Most Athletes Are Not Thinking About

Potassium is the primary electrolyte found inside cells and works along with sodium for cellular functions. Like sodium, the kidneys regulate blood levels of potassium. (1)

Potassium is very important for muscle function, including the heart. As muscles contract, potassium moves out of the muscle cells. After exercise, potassium moves back into the muscles. These shifts in potassium during exercise, especially prolonged or intense exercise, can affect muscle function and contribute to muscle weakness and fatigue. (1, 7, 8)

Therefore, low potassium levels (hypokalemia) can affect muscle contractility of both the Low potassium levels, known as hypokalemia, can affect the contractility of both skeletal muscle and the heart and reduce athletic performance. However, the normal shifts in potassium that occur during training are not necessarily the same as potassium deficiency. (8, 9

So, if sodium is on your radar, potassium should be as well.

Signs of Electrolyte Imbalance During Training and How to Address Them

Dehydration and electrolyte losses through sweating can contribute to a wide range of symptoms. Dehydration can occur because of low fluid intake, increased fluid loss, or both, and hot weather can increase these losses. Even mild water and electrolyte losses may impair performance. (10, 11)

Low electrolyte symptoms may include:

• Thirst
• Nausea
• Lightheadedness
• Dizziness
• Heart palpitations
• Headaches 
• Fatigue
• Muscle cramps
• Decreased urination
• Dark urine
• Dry lips, tongue, mouth 
• Changes in mental and physical performance (12)

Because these symptoms are not specific to electrolyte deficiency, consider exercise duration, heat exposure, sweat losses, and overall fluid intake when deciding how to respond. Addressing dehydration and electrolyte losses may require hydration, electrolyte replacement from an electrolyte drink mix, and possibly additional carbohydrates, or glucose. Read more about when you need supplemental glucose during training here. 

How to Find the Right Electrolyte Intake for Your Training Volume and Sweat Rate

Are electrolytes good for you? Yes, but like everything in nutrition, you need the right balance. 

Replacing fluids and electrolytes when training and sweating requires a personalized approach. The amount of replacement you need depends on your activity level, sweat loss, water and electrolyte intake, and even the climate in which you are training. 

The goal is to begin training well hydrated, replace enough fluid and electrolytes during exercise to limit excessive losses without overdrinking, and continue replacing any remaining losses after exercise.

While there is no one-size-fits-all rule for taking electrolytes, here is some general guidance to get you started:

• For short duration or low-intensity exercise, water replacement may be enough

• For exercise longer than 90-120 minutes in duration, replace water and electrolytes during and after training (and likely glucose during training too)

• Consider additional electrolytes for endurance or ultra-endurance sports, when sweating is excessive, and in hot weather. (6, 13, 14)

Pro tip: Estimate your sweat rate by taking body weight before and after exercise. (14)

What to Look for in an Electrolyte Supplement, and What to Avoid

For athletes who need targeted hydration and electrolyte replacement, an electrolyte drink mix can be a convenient option. 

When choosing the best electrolyte powder for performance, look for transparent amounts of sodium and potassium, along with ingredients that support hydration and training demands. Outwork Nutrition Electrolytes contains 500 mg of sodium and 200 mg of potassium per serving, along with magnesium and dextrose, a glucose source. This balanced formula supports fluid and electrolyte replacement during prolonged, high-intensity, or high-sweat training.

Use the electrolytes before, during, and after exercise, as needed. Simply mix one scoop with 16 ounces of water. 

Use Outwork Nutrition Electrolytes by itself or pair it with Outwork Nutrition Recovery to support recovery and maintain hydration between training sessions. Our recovery formula includes creatine monohydrate, betaine, L-carnitine, tart cherry, and ashwagandha to support recovery and muscle growth, with cumulative effects over time.

The best way to get electrolytes depends on your training duration, sweat rate, climate, diet, and individual needs. Look for supplements that disclose ingredient amounts, use evidence-based dosages, and are lab-tested for quality and purity. Electrolyte drinks without sugar may be appropriate for some situations, but a small amount of glucose can support sodium and water absorption while also providing carbohydrate during longer or more demanding training sessions.

When comparing the best electrolytes for performance, prioritize a formula that matches your actual fluid, sodium, and training needs. Outwork Nutrition provides transparent, evidence-based hydration and performance support. 

Electrolyte FAQs

How do you know if you need more electrolytes during training?

Symptoms such as nausea, weakness, dizziness, or impaired performance can have several causes and do not automatically mean you need more electrolytes. Electrolyte replacement may be useful however especially during prolonged or high-intensity exercise, training in hot weather, or situations involving high sweat and sodium losses.

Should athletes take electrolytes before, during, or after a workout?

You can take electrolytes before, during, and after a workout depending on exercise intensity, weather, sweat levels, and personal needs. The goal is to replace any electrolytes lost during training. 

What is the difference between sodium and other electrolytes for performance?

Sodium is one electrolyte; potassium, magnesium, calcium, chloride, phosphorus, and bicarbonate are others. Each serves a specific physiological role and contributes to fluid balance, nerve signaling, or muscle function. Because sodium is the primary electrolyte lost in sweat, it is often the main focus of electrolyte replacement during prolonged or high-sweat exercise.

Can drinking too many electrolytes actually be harmful?

Like everything, balance is key. Taking too many electrolytes can be harmful. For example, excess sodium can raise blood pressure, and too much potassium can affect heart function. However, for healthy people, the kidneys are very efficient at removing excess sodium and potassium as needed. 

What are the best natural sources of electrolytes for athletes?

Athletes can prioritize foods high in electrolytes, such as sea salt for sodium and bananas, potatoes, and coconut water for potassium. Additionally, electrolytes before or after a workout (or during) from Outwork Nutrition Electrolytes provide targeted support to maintain hydration and electrolyte balance. 

References

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