Electrolytes - Why They are Important in Your Personal Training Nutrition Plan


In this blog we will talk about importance of including electrolytes in our personal training nutrition plan, their functions, and how electrolyte imbalance can influence your athletic performance.

Electrolytes - Why They are Important in Personal Training Nutrition Plan

Table of contents

What are electrolytes?

Electrolyte imbalances

Causes of electrolyte imbalances

Symptoms of electrolyte imbalances

What is metabolic acidosis?

What is the most common electrolyte imbalance in endurance athletes?

Hormones and electrolytes

Is drinking too much water bad for you?

What happens if you cut salt entirely out of your diet?

Dietary sources of electrolytes

Maintaining homeostasis can be challenging, especially as most athletes concentrate on macronutrient intake, forgetting about the importance of micronutrients. Micronutrients are crucial for electrolyte balance and the proper functioning of endocrine and nervous systems, and, therefore, they, directly and indirectly, influence the levels of electrolytes in your body. Hydration is also strictly linked to electrolyte levels, and there is so much confusion around this topic, at least when it comes to endurance sports. Optimal hydration guidelines for endurance athletes are still controversial; so, electrolyte imbalances that may occur during and after training or competitions represent one of the biggest challenges to overcome. Most studies underline dehydration’s detrimental consequences, while recently, hyperhydration is emerging as a more significant problem. Most scientists agree that individualized recommendations regarding proper hydration are the best solution to avoid significant health consequences.

In this article, we will explain what electrolytes are, their functions, and how electrolyte imbalance can influence your athletic performance.

What are electrolytes?

Electrolytes are electrically charged particles (negative or positive) that facilitate cell activity and the transmission of impulses. Electrolytes are minerals dissolved in your bodily fluids, such as blood, urine, sweat, etc. These particles are dispersed in physiological, intra-, and extracellular fluids like plasma, lymphatic fluid, cytosol, etc. The exchanges between cells and extracellular fluids are essential for maintaining numerous physiological functions. For example, sodium is the primary electrolyte found in extracellular fluids, and potassium is the primary intracellular electrolyte. These two electrolytes are involved in fluid balance and blood pressure control. One of the essential homeostatic functions, called osmoregulation of the body, is maintaining fluid balance and the composition between fluid compartments. Osmosis is the process that permits the movement of water between fluid compartments. The electrolyte balance is maintained with the diet and various physiological mechanisms regulated by hormones like parathyroid hormones and aldosterone. These hormones interact with kidneys, which tend to eliminate excess electrolytes with urine.

Electrolytes found in our body are:

• Calcium (Ca2 +)

• Chloride (Cl-)

• Phosphate (HPO42-)

• Magnesium (Mg2 +)

• Potassium (K +)

• Sodium (Na +)

• Bicarbonate (HCO3-)

The plus (+) and minus (-) electric charge symbols indicate that the substance is ionic and has an unbalanced electron distribution.

Electrolytes help many different bodily functions:

• Control nerve and muscle function

• Balance body fluids

• Regulate the body’s pH levels

• Regulate blood pressure

Electrolyte imbalances

An electrolyte imbalance occurs when electrolyte levels are too high (hyper) or too low (hypo). Let’s take calcium as an example; we may have hypocalcemia (low calcium) or hypercalcemia (high calcium). For women, hypocalcemia is a risk factor for osteoporosis during premenopause. On the other hand, hypercalcemia can lead to the formation of kidney stones. Electrolyte imbalances are more common than you might think, especially in endurance athletes. Some imbalances are temporary, as our body, through hormone secretion and renal function, balances fluid and electrolyte levels. Sometimes, though, external intervention is required. The most common imbalances, significant symptoms, and complications arise when sodium, potassium, or calcium imbalances occur. While most of these imbalances are temporary, complex situations can still happen, and severe electrolyte imbalances can lead to serious health conditions, like potentially fatal arrhythmias, seizures, etc. Potassium is perhaps the electrolyte that, more than others, can lead to severe medical conditions that require prompt intervention. Myocardiocytes, the heart muscle cells, need specific potassium values to keep the heart rate within normal parameters. Hypokalemia (low potassium in the blood) can cause potentially fatal arrhythmias, while hyperkaliemia can lead to kidney problems. Unfortunately, sometimes the first manifestation of this imbalance can be kidney failure or cardiac arrest. A proper endurance athlete meal plan is one of the main keys to maintaining electrolyte balance, including a well-planned hydration routine.

Causes of electrolyte imbalances

Electrolyte imbalances are the result of an alteration in the balance of electrolytes. An electrolyte imbalance can be caused by:

• Dehydration

• Hyperhydration

• Medicines like ACE inhibitors, diuretics, corticosteroids, some antibiotics, etc.

• Heart, kidney, or liver diseases

• Malabsorption syndrome

• Endocrine diseases

• Heatstroke

Symptoms of electrolyte imbalances

Electrolyte imbalance can manifest in numerous ways, and symptoms will depend on which electrolyte is in imbalance and whether the level is too high or too low. Let’s take a look at some of the most common symptoms:

Sodium deficiency: craving for salty foods, extreme fatigue, muscle weakness, increased urination;

High sodium: thirst, dry mouth, muscle spasms, breathing difficulties;

Potassium deficiency: weakness, fatigue, constipation, leg cramps, arrhythmias;

High potassium: muscle weakness, tingling, loss of sensation in the muscles, mental confusion, arrhythmias;

Calcium deficiency: muscle cramps, tremors, brittle and weak bones, irregular heartbeat;

High calcium: weakness, muscle aches, constipation, kidney stones;

Magnesium deficiency: tremors, disorientation, difficulty swallowing and breathing, muscle cramps;

High magnesium: red and hot skin, reduced reflexes, weakness, vomiting.

Acid-base imbalance: nausea, vomiting, headaches, irritability, lethargy, and tingling in hands and face.

What is metabolic acidosis?

Metabolic acidosis is a type of electrolyte disorder that happens when there is an imbalance in the body’s acid-base balance.

There are three primary types of metabolic acidosis:

1. Diabetic acidosis – kidneys cannot remove enough acid from the body, and substances like ketones accumulate in your body.

2. Hypercholermic acidosis – reduced levels of bicarbonate in the blood

3. Lactic acidosis – the most common type of metabolic acidosis. It is a consequence of the accumulation of lactic acid in the body. It decreases the pH levels, which, in the long run, can cause significant health problems.

The symptoms of metabolic acidosis mainly depend on the cause. Mild cases can be asymptomatic, while more severe acidosis (pH smaller than 7.10) can cause nausea and vomiting associated with headache, fatigue, muscle cramps, loss of appetite, fluid retention, etc. The most characteristic sign is hyperpnea and tachypnea (deep and fast breathing - hyperventilation).

Severe and acute acidosis can lead to cardiac dysfunction with hypotension with ventricular arrhythmias. Chronic acidosis, on the other hand, causes bone demineralization disorders.

What is the most common electrolyte imbalance in endurance athletes?

The most common electrolyte imbalance in endurance athletes is hyponatremia or low sodium concentration in the blood (lower than 135 mEq/L). This imbalance needs to be taken seriously as it is associated with both mortality and morbidity. Hyponatremia is usually caused after prolonged endurance training or competition, especially in a warm environment because of increased sweating, excessive intake of hypotonic fluids, and a diet low in sodium. Its incidence is proportional to the duration of the training. It occurs above all in those athletes who participate in endurance competitions such as marathons and triathlons. These are high-intensity aerobic activities that last between 6 and 8 hours, and hyponatremia can manifest already after 4 hours of intense activity. More than 10% of athletes have hyponatremia with Na + levels smaller than 135 mEq/L, but first symptoms begin to show only after the levels go under 125 mEq/L. This study reported that 73% of severe hyponatremia cases after the New Zealand Ironman Triathlon resulted from water overload. Another interesting research observed that athletes hydrated with hypotonic solutions, in association with sodium losses due to sweating, were more prone to develop hyponatremia. They consider an intake of approximately 500ml/h to be appropriate. The International Marathon Medical Directors Association recommends a water intake of 400-800 ml/h for marathon runners.

Long and intense endurance training induces a series of electrolyte alterations, not just hyponatremia. This does not mean that supplementation is necessary. Proper nutrition and correct hydration can be more than enough. For example, according to this study, potassium and magnesium supplementation is contraindicated during long-distance running.

Hormones and electrolytes

The organs that play a crucial role in regulating the volume and constituents of body fluids, maintaining acid-base balance, and excreting the body’s final metabolic products are kidneys. The endocrine and nervous systems control all renal functions. Here are some of the most important hormones which regulate electrolyte levels to maintain proper homeostasis. Above each kidney, there is an adrenal gland. Their primary role is to produce hormones like adrenaline, cortisol, and aldosterone. The renin-angiotensin-aldosterone system regulates blood sodium and potassium levels, blood pressure, and volume. The levels of these hormones increase during strenuous training and return to normal levels at the end of the training. Many factors influence this system like age, gender, nutrition, duration of the training, etc. Now let’s take a look at how these hormones influence potassium and sodium levels. Aldosterone influences the vascular tone, the hydro electrolytic balance, and the sympathetic nervous system’s activity. The kidneys are stimulated by aldosterone to reabsorb sodium back into the body and excrete potassium in the urine. Kidneys secret an enzyme called renin, which controls the hormone angiotensin’s activation, stimulating the adrenal glands to produce aldosterone. Aldosterone secretion is also regulated by potassium. Potassium directly increases the secretion of aldosterone by the adrenal cortex, and aldosterone reduces potassium levels by stimulating its excretion in the kidney. High levels of aldosterone can cause low potassium levels and high blood pressure. Low potassium levels can cause weakness, tingling, muscle spasms, and ventricular arrhythmias. Antidiuretic hormone (ADH) stimulates the kidneys to excrete more solutes in the form of concentrated urine. It reduces sodium concentrations and increases water reabsorption in the kidneys. Plasma levels of this hormone increase during intense and prolonged physical activity.

Is drinking too much water bad for you?

As an endurance athlete, you must face each training session adequately hydrated. Even partial dehydration can cause significant physical stress, overall fatigue, and increased risk of muscle injuries. Other than hormone changes, a warm environment and sweating are important risk factors for electrolyte imbalance during competitions. Sweating is very subjective, but you should limit fluid losses during training or competition events within 1% of body weight. On the other hand, the problem of hyperhydration is often underestimated. Just as drinking too little water, too much water can also lead to serious health issues, as it dilutes the amounts of electrolytes in your bloodstream. If the amount of water ingested does not correspond to the amount eliminated, it accumulates rapidly. This accumulation can lead to water retention, insomnia, electrolyte imbalances, renal problems, and in severe cases, it can be fatal. The biggest problem of drinking too much water is the electrolyte imbalance, as it can cause potentially fatal ventricular arrhythmias. The most common electrolyte alterations when drinking too much water are those of sodium and potassium. In fact, some studies have shown that overhydration could be potentially more dangerous than dehydration, and supplements may not be much of a help. This particular study reported that in the case of overhydration in ultramarathon runners, sodium supplementation is not a valid solution for preventing exercise-associated hyponatremia (low sodium levels). The amounts and timing of sodium supplement ingestion showed almost no effect on sodium levels. This study showed that sodium supplementation in triathletes during the South African Ironman triathlon was not associated with a better or lower athletic performance. Some studies show a slight increase in sodium levels and lessen body mass loss after salt supplement ingestion during ironman triathlons. However, there is still too little evidence supporting salt supplementation as a valid method in preventing exercise-associated hyponatremia and improving athletic performance.

What happens if you cut salt entirely out of your diet?

It is absolutely not a good idea to cut salt entirely out of your diet. Adequate consumption of salt is crucial for maintaining proper physiological functions. Only for those who have preexisting health issues like high blood pressure or severe water retention, salt intake reduction is a must. Excessive salt consumption increases water retention and can cause many serious health problems, especially to the cardiovascular system.

As an endurance athlete, you should be very careful about your daily sodium intake, as it is very easy to go out of the limits, especially before competitions. If it is a temporary issue, then no important consequences should occur, but if the deficiency or the excess becomes chronic, you could face some serious problems. If your heart, muscles, or nerves become affected, it is easy to comprehend that this would have a substantial negative impact on your performance.

Dietary sources of electrolytes


The recommended intake should not exceed 1000 mg per day.

Best dietary sources:

• Aged cheeses (Parmesan 1159mg/100g, Gruyere 1123mg/100g, etc.)

• Sardines (380mg/100g)

• Fortified tofu (350mg/100g)

• Soybeans (280mg/100g)

• Caviar (275mg/100g)

• Anchovies (232mg/100g)

• Kale (150mg/100g)

• Cow milk (125 mg/100ml)

• Beans (113mg/100g)

• Greek yogurt (110mg/100g)

• Broccoli (50mg/100g)

• Herbs like rosemary, sage, thyme.


The recommended intake should not exceed 700 mg per day.

Best dietary sources:

• Cooked mollusks (585mg/100g)

• Almonds (458mg/100g)

• Gorgonzola cheese (420mg/100g)

• Chickpeas (366mg/100g)

• Walnuts (346mg/100g)

• Salmon (305mg/100g)

• Soybeans (216mg/100g)

• Eggs (215mg/100g)

• Lamb (201mg/100g)

• Arrowhead (197mg/100g)

• Lentils (193mg/100g)

• Orzo (189mg/100g)

• Quinoa (152mg/100g)


The recommended intake should not exceed 2300 mg per day.

Best dietary sources:

• Salt, table (38758mg/100g)

• Fish, mackerel, salted (4450mg /100g)

• Miso (3728mg/100g)

• Tofu, salted and fermented (2873mg/100g)

• Turkey bacon, cooked (2285mg/100g)

• Beef, bacon, cooked (2253mg/100g)

• Pork, cured, bacon, cooked (2193mg/100g)


The recommended intake should not exceed 420 mg per day for men and 320 mg for women.

Best dietary sources:

• Soybeans (279mg/100g)

• Pumpkin seeds (262mg/100g)

• Almonds (260mg/100g)

• Bran (235mg/100g)

• Dark chocolate (252mg/100g)

• Peanuts (164mg/100g), walnuts (158mg/100g)

• Whole grains (80mg/100g)

• Spinach (79mg/100g)

• Banana (27mg/100g)

• Salmon (25mg/100g)


The recommended intake should not exceed 4700 mg per day.

Best dietary sources:

• Dates (655mg/100g)

• Spinach (558mg/100g)

• Potatoes (413mg/100g)

• Banana (361mg/100g)

• Raisins (335mg/100g)

• Mushrooms (333mg/100g)

• Apricots (270mg/100g)

• Peas (243mg/100g)

• Tomatoes (236mg/100g)

• Orange (173mg/100g)

• Broccoli (162mg/100g)

• Cucumbers (136mg/100g)

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