Electrolytes & Hydration
By Vishal Patel,
Nuun Chief Nutritionist
Did you know that what you hydrate with is just as crucial as any other nutritional strategy you take on? A sports drink that is easily metabolized will help with hydration, but electrolytes are the key. For optimal hydration choose a beverage that is easily tolerated and digested, but most importantly, one that has a well-balanced electrolyte profile.
But what do electrolytes do?
Electrolytes are tiny particles that carry electrical charges. They serve many roles to help the body maintain proper function. When you sweat, electrolytes play key roles in keeping water balanced both inside & outside of cells so that your muscles and organs can continue to serve you properly (1).
So, why are electrolytes important?
When you sweat your body loses both fluid and electrolytes. If you don’t begin your workout properly hydrated, and/or you aren’t hydrated properly during your activity, dehydration can occur through the act of sweating. Everyday life calls for everyday electrolytes. Staying hydrated through your workday or daily to-do list are important too!
Dehydration has several negative impacts. But even if you don’t feel a difference, as little as 2% dehydration can result in a decrease in performance. Remember thirst is the #1 indicator that you may be dehydrated.
Replenishing electrolytes via sports drink helps to replenish your mineral losses; but electrolytes also help make the most of your water, which is the key to proper hydration. Sports drinks high in sodium, potassium, magnesium, and calcium can help retain fluids, and proper fluid balance contributes to optimal performance.
Sodium (Na) – maintains fluid balance
Sodium is the most important electrolyte to monitor during training. Excessive losses of sodium (via sweat) can lead to muscle cramps, and in some cases hyponatremia (low blood sodium) – both can lead to a decrease in performance, and can cause major health complications (2). Sodium is critical for maintaining fluid balance, nerve function, muscle contractions, and acid-base balance (2). Sodium losses in sweat are greater than any other electrolyte. Therefore, it is crucial to maintain an adequate balance, both during your activity and after.
Potassium (K) – prevents cramping
Potassium in conjunction with sodium helps alleviate and prevent muscle cramps (2). Potassium is abundant in many food sources, and the average individual has high stores within the body. In sweat, potassium losses are not as high as sodium. Therefore, making it highly unlikely that losses in potassium (alone) can cause a decrease in performance. With that said, it is still crucial to maintain potassium levels while training as it will be critical for a healthy water & electrolyte balance.
Calcium (Ca) – regulates muscle contractions & heart rhythm
Calcium is the most abundant mineral in the body (2). It serves many roles both in normal bodily functions, and athletic performance. When calcium is circulating within the bloodstream it has a major impact on metabolism of essential nutrients, and proper physiological functions. It is well documented that calcium is essential for bone and muscle health. Calcium is also involved in all types of muscle (heart, skeletal, and smooth) functions and contractions (1). And lastly, calcium is involved in the synthesis and breakdown of muscle and liver glycogen (fuel stores)(2).
Magnesium (Mg) – relaxes muscles
Similar to how sodium and potassium function together, magnesium and calcium do the same. Calcium is essential for muscle contractions; magnesium aids in helping muscles relax (1). Therefore, the combination of magnesium and calcium is critical for healthy muscle function. Magnesium also aids in glucose metabolism, and it used in many enzymatic reactions (3).
How many electrolytes do I need?
Several factors come into play when determining electrolyte losses such as: fitness level, activity duration, and environmental factors. During conditions in which both temperatures and humidity are high, the body works harder, thus increasing internal body temperature (thermoregulation). With this increase, the body needs to release heat (through sweat), and electrolytes can be lost at a greater rate. During strenuous activities in which sweat rates may be greater, or the duration is longer it is essential to replace electrolytes through fluids, and be aware of signs of dehydration.
Daily requirements for these mineral vary on gender, age, and in some cases, fitness activity level/duration. The Institute Of Medicine (IOM) has set standards for each of these minerals (4).
- For both males and females it is recommended to keep sodium intake below 2,000 mg.
- Potassium recommendation for males and females are 4,700 mg per day. Potassium is rich in many foods, and will not need additional supplementing. However, intake in potassium during training can help maintain water and electrolyte balance.
- Magnesium intake for males should be between 330-350 mg per day, and females should intake about 255-265 mg per day. However, hot and humid conditions can cause magnesium store to be excreted via sweat at higher rates so more must be replenished.
- Calcium is essential, and is found in many food items. The suggested intake is 800 mg per day for both males and females.
Additional resources
- Clark, N. (2008). Sports Nutrition Guidebook. 4th Ed., Champaign, Il: Human Kinetics.
- Ryan, M. (2012). Sports Nutrition for Endurance Athletes. 3rd Ed. Boulder, Co: Velopress
- Fink, H.H, Burgoon, L.A, Mikesky, A.E. (2009). Practical Applications in Sports Nutrition. 2nd Ed., Pp 220-254. Sudbury, Ma: Jones and Bartlett Publishers, LLC.
- Institute Of Medicine (IOM) DRI’s For Micronutrients
