Electrolytes Explained: Why They Matter and How to Choose the Right Electrolyte Supplement
- Michaela Newsom
- Jun 27
- 9 min read
Key Takeaways
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Table of Contents
Electrolytes: More Than Just Hydration
Walk into any health food shop and you'll find shelves full of electrolyte powders promising better hydration, more energy and improved performance.
While electrolyte supplements have become increasingly popular, they're often misunderstood.
Many people assume they're simply for athletes. Others believe everyone should be drinking them daily. The truth sits somewhere in the middle.
Electrolytes are essential for life. Every heartbeat, muscle contraction, nerve impulse and cellular process depends on them. However, whether you need an electrolyte supplement—and which one is best—depends entirely on your individual physiology and lifestyle.
What Are Electrolytes?
Electrolytes are minerals that carry an electrical charge when dissolved in body fluids. These tiny charged particles allow cells to communicate with one another and help regulate countless physiological processes.
The major electrolytes include:
Sodium – regulates fluid balance, blood volume and nerve signalling
Potassium – supports muscle contraction, heart rhythm and intracellular fluid balance
Magnesium – required for over 300 enzymatic reactions, ATP production and muscle relaxation
Calcium – essential for muscle contraction, nerve transmission and bone health
Chloride – works alongside sodium to maintain fluid balance and stomach acid production
Phosphate – involved in energy (ATP) production, cell membranes and bone health
Without adequate electrolyte balance, cells struggle to communicate efficiently, affecting everything from brain function to exercise performance.
Why Are Electrolytes So Important?
Although hydration often gets the attention, electrolytes do much more than simply help you retain water.
They regulate fluid balance
Water naturally follows electrolytes. Sodium and potassium work together to control how much water remains inside and outside your cells, helping maintain blood volume, circulation and hydration. This is why drinking excessive amounts of plain water after prolonged sweating can sometimes worsen electrolyte imbalances rather than correct them.
They allow nerves to communicate
Every thought, movement and sensation relies on electrical impulses travelling along nerves.
These electrical signals depend on precise movements of sodium, potassium and calcium across cell membranes. Even small disturbances can affect muscle function, concentration and coordination.
They support muscle function
Muscles contract when calcium enters muscle cells and relax when magnesium helps regulate the process. Sodium and potassium generate the electrical signals that initiate contraction.
When electrolyte balance becomes disrupted, muscles may fatigue more quickly or become more susceptible to cramping, although exercise-associated cramps are complex and cannot be explained by electrolyte losses alone.
They help produce cellular energy
One of the lesser-known roles of electrolytes is their involvement in energy production. Magnesium is required to activate ATP—the body's energy currency—while phosphate forms part of the ATP molecule itself. Without sufficient magnesium, ATP cannot be efficiently utilised inside cells.
This is one reason why magnesium deficiency can contribute to fatigue, poor recovery and reduced exercise tolerance.
Signs You May Need More Electrolytes
Most people obtain adequate electrolytes from food. However, certain situations increase requirements, including:
prolonged exercise lasting over 60–90 minutes
exercising in hot or humid weather
heavy sweating ("salty sweaters")
vomiting or diarrhoea
sauna use
ketogenic or very low-carbohydrate diets
fasting
certain medications including some diuretics
gastrointestinal disorders that impair nutrient absorption
Symptoms associated with electrolyte depletion may include:
headaches
fatigue
dizziness on standing
muscle cramps
reduced exercise performance
poor recovery
brain fog
increased heart rate during exercise
These symptoms are non-specific, so persistent symptoms should always be properly assessed rather than assumed to reflect an electrolyte deficiency.
Do You Actually Need an Electrolyte Supplement?
Not necessarily. If you're generally healthy, eat a varied whole-food diet and perform moderate exercise, plain water alongside a balanced diet will usually meet your needs.
As electrolyte supplements are trying to replace what you have lost, they are more useful when fluid and mineral losses are substantially increased, such as during prolonged endurance exercise, manual work in hot conditions or illness causing dehydration.
For this reason, a person undertaking light exercise taking an electrolyte supplement will need a different electrolyte profile compared to an endurance athlete. In the case of endurance athletes, sodium replacement is particularly important because it is the electrolyte lost in the greatest quantity through sweat.
What to Look for in a High-Quality Electrolyte Supplement
Not all electrolyte products are created equal. Here are the features worth looking for:
Appropriate sodium content
If you're replacing sweat losses, sodium is the most important electrolyte to replace. Many people are surprised to learn that sodium and not magnesim is the electrolyte that matters most during exercise. Many products contain impressive amounts of magnesium but very little sodium. Look for products that provide meaningful amounts of sodium rather than relying primarily on magnesium alone.
Potassium
Potassium works alongside sodium to regulate fluid balance and muscle function. Sweat losses are much lower than sodium losses, so only modest replacement is generally required. Very high doses are rarely necessary unless specifically recommended by your healthcare practitioner.
Magnesium
Magneisum is essential for muscle relaxation, nerve signalling and ATP production but sweat contains very little magnesium. So whilst magneisum status is important, high doses in electrolyte mixes are not necessary. If you have low magnesium status, it's usually more effective to take a seperate magnesium supplement rather than rely on an electrolyte.
Electrolyte balance is about ratios, rather than just increasing intake.
Minimal added sugar
For most everyday hydration, choose products with little or no added sugar. However, during prolonged endurance exercise lasting over 90 minutes, carbohydrate-containing drinks can improve performance by supplying both energy and fluid.
Clean ingredient list
Ideally choose products that avoid:
artificial colours
unnecessary sweeteners
excessive fillers
proprietary blends that don't disclose ingredient amounts
Choosing the Right Electrolyte Supplement for Your Lifestyle
One size definitely does not fit all. One of the most confusing aspects of buying an electrolyte supplement is knowing what the numbers on the label actually mean. Some products contain just a pinch of sodium, while other provide over 1000mg per serving.
The "right" amount depends on how much fluid and sodium you are losing, rather than how mcuh you're exercising.
The recommended dietary intake (RDI) for potassium (3500mg/day) is much higher than for sodium (1600mg/day) so it may seem logical that an electrolyte supplement should also contain more potassium than sodium. However, dietary recommendations are based on total daily nutiritonal needs whilst electrolyte supplements are designed to replace what is being lost acutely. The electrolyte composition of sweat is very different to the composition of the diet.
Typical sweat losses per litre:
Sodium: 500-1000mg (although 'salty' sweaters can lose more than 1500-2000mg per litre)
Potassium: 100-250mg
Magnesium: less than 15mg
Calcium: 10-30mg
For everyday hydration
A balanced diet will typically provide all the electrolytes that you need. Plain water is typically sufficient for every day hyrdation. However, if you are experiencing symptoms that may suggest electrolyte support is required, coconut water is a good option as it contains a natural mix of electrolytes with a slightly higher potassium content.
Recommended products:
BodyBio E-Lyte is designed to support normal physiologial electrolyte balance and provides Potassium 187mg, Sodium 89mg, Magnesium 65mg. However, I would not choose it for someone training for a marathon or playing several hours of tennis in 30deg heat.
Mineral Resources International Elete Electrolytes provide Sodium 125mg, Potassium 133mg, Magnesium 45mg.
For light to moderate exercise (<60 minutes), hot weather or severe hot flashes
Electrolytes may be useful after sweaty workouts, during hot weather or if you suffer frequent or severe hot flashes or night sweats. Aim for:
Sodium: 200-300mg
Potassium: 50-100mg
Magneisum: 20-50mg
Recommended product:
Thorne Daily Electrolytes provide Sodium 480mg, Potassium 99mg, Magnesium 40mg per serving (a half serving will provide the correct balance for light to moderate exercise).
For regular gym sessions and moderate sweating (60-90 minutes)
When sweat losses become more signifcant from regular gym sessions, a higher ratio of sodium becomes more important. Aim for:
Sodium: 300-600mg
Potassium: 100-200mg
Magneisum: 25-75mg
Recommended product:
Thorne Daily Electrolytes provide Sodium 480mg, Potassium 99mg, Magnesium 40mg.
For heavy sweating or endurance exercise (>90 minutes)
Long-distance runners, cyclists and triathletes often require higher sodium intake during prolonged exercise to replace sweat losses and support fluid retention. Products containing sodium alongside modest carbohydrate are generally more appropriate than plain water alone.
Aim for:
Sodium: 600-1000mg (more in very 'salty' sweaters)
Potassium: 200-400mg
Magnesium: 50-100mg
Carbohydrate: 30-60g carbohydrate per hour
Recommended products:
LMNT provides 1000mg Sodium, 200mg Potassium, 60mg Magnesium.
Vivo Life Sustain Electrolytes provides Sodium 1000mg, Potassium 250mg, Magnesium 100mg, Calcium 50mg
For a ketogenic or low-carbohydrate diet
Lower insulin levels increase sodium excretion by the kidneys, meaning sodium requirements may be higher, particularly during the first few weeks of dietary change. A ketogenic diet maybe lower in vegetables and therefore risks lower potassium intake so a slightly higher potassium content maybe benefical. However, to remain in ketosis, it should not contain added carbohydrate.
Recommended products:
Love Life Supplements Ultimate Electrolytes provide 500mg Sodium, 500mg Potassium, 150mg Magnesium.
LMNT provides 1000mg Sodium, 200mg Potassium, 60mg Magnesium.
Vivo Life Sustain Electrolytes provide Sodium 1000mg, Potassium 250mg, Magnesium 100mg, Calcium 50mg
For illness
Vomiting or diarrhoea can rapidly deplete both fluids and electrolytes. In these situations, an oral rehydration solution (ORS) is usually more appropriate than a standard sports drink because it contains a carefully balanced combination of sodium and glucose to maximise water absorption in the intestine.
Recommended product:
Dioralyte is a specialist product designed to rehydrate after illness.
Can You Take Too Many Electrolytes?
Yes. More isn't always better.
Excessive electrolyte supplementation—particularly sodium or potassium—may be harmful in people with kidney disease, uncontrolled hypertension or certain heart conditions.
If you have kidney disease, take blood pressure medication, ACE inhibitors, potassium-sparing diuretics or have been advised to restrict sodium or potassium, always speak with your healthcare professional before using electrolyte supplements.
As with most aspects of nutrition, the goal is balance—not excess.
The Bottom Line
Don't judge an electrolyte supplement by the total amount of minerals it contains. Many brands advertise high magnesium or include dozens of "trace minerals," but for hydration and sweat replacement, the sodium content is usually the most important figure to look at, as sodium is lost in the greatest quantity through sweat and plays the largest role in promoting water absorption.
Disclosure
The products mentioned in this article are based solely on my professional opinion, clinical experience and personal use. I am not affiliated with any of the brands featured, do not receive commission or financial compensation for recommending them, and have no commercial relationship with the manufacturers. Where I recommend a product, it is because I believe it offers good quality, appropriate formulation and value for the individuals it is intended to support. As always, the most appropriate choice will depend on your own health, lifestyle and individual needs.
Frequently Asked Questions
Are electrolytes better than water?
Not necessarily. For everyday hydration, water is perfectly adequate for most people. Electrolytes become beneficial when substantial fluid and mineral losses occur through heavy sweating or illness.
Do electrolytes give you more energy?
Not directly. They don't contain energy themselves, but they support the physiological processes involved in producing and using ATP. If dehydration or electrolyte imbalance is contributing to fatigue, correcting that imbalance may improve how you feel.
Which electrolyte is most important?
All electrolytes work together, but sodium is generally the most important mineral to replace during heavy sweating because it is lost in the greatest amounts.
Should everyone take electrolytes every day?
No. Most healthy adults obtain sufficient electrolytes through a balanced diet. Daily supplementation is usually unnecessary unless you have increased losses or specific clinical needs.
Can electrolyte supplements help with menopause?
Potentially. Women experiencing hot flushes, night sweats, frequent exercise or sauna use may lose more fluid than expected. Replacing fluids alongside appropriate electrolytes may support hydration and wellbeing, although electrolyte supplements do not treat the underlying hormonal changes associated with menopause.
References and Further Reading
Shrimanker I, Bhattarai S. Electrolytes. StatPearls Publishing. 2023.
Pérez-Castillo IM, et al. Compositional Aspects of Beverages Designed to Promote Hydration Before, During and After Exercise. Nutrients. 2023.
Ly NQ, et al. Post-Exercise Rehydration in Athletes: Effects of Sodium and Carbohydrate in Oral Rehydration Solutions and Sports Drinks. Nutrients. 2023.
De Brier N, et al. Oral Rehydration Beverages for Treating Exercise-Associated Dehydration. Sports Medicine. 2025.
McCubbin AJ, et al. Sodium Intake for Athletes Before, During and After Exercise. Sports Nutrition. 2025.
Amawi A, et al. Athletes' Nutritional Demands: A Narrative Review. Frontiers in Nutrition. 2024.
Veniamakis E, et al. Effects of Sodium Intake on Health and Performance in Physically Active Individuals.Nutrients. 2022.
Jung AP, Bishop PA. Influence of Hydration and Electrolyte Supplementation on Exercise-Associated Muscle Cramps. Journal of Athletic Training. 2005.
About The Author
Michaela Newsom
Registered Nutritional Therapist, mBANT, rCNHC
Michaela is a women’s health expert with a specialist interest in the impact of menopause on the female brain. Her mission is to empower women to optimise their cognitive function and mental wellbeing throughout life with a special focus on the challenges that take place during perimenopause, menopause and beyond.
With a Postgraduate qualification in Personalised Nutrition and advanced Functional medicine training with IFM and the Kharrizian Institute Michaela has expertise spanning hormones, brain health, cognitive function and mood disorders.
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