What Are Electrolytes - And Do You Actually Need a Supplement?
What are electrolytes - and do you actually need a supplement?
Electrolytes are one of those terms that appears constantly in sports and wellness marketing - but the actual explanation of what they are and why they matter is often surprisingly unclear. Here is the honest answer to both questions, and a straightforward guide to when supplementation is genuinely useful versus unnecessary.
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Sodium
The primary electrolyte in extracellular fluid - the fluid outside your cells. Sodium regulates fluid balance, blood pressure and nerve signal transmission. It is lost in the highest quantities through sweat - which is why sweat tastes salty. Sodium depletion during prolonged exercise causes muscle cramps, nausea and fatigue.
Potassium
The primary electrolyte inside cells. Works in balance with sodium to regulate fluid movement into and out of cells, supports muscle contraction and relaxation, and is essential for heart rhythm. Low potassium (hypokalaemia) causes muscle weakness, cramps and fatigue.
Magnesium
Required for over 300 enzymatic reactions in the body including ATP production (the energy currency of cells), protein synthesis and muscle relaxation. Magnesium is the most commonly deficient mineral in the UK population - studies suggest up to 68% of UK adults do not reach the recommended daily intake from food alone.
Calcium
Best known for bone health, but calcium also plays a critical role in muscle contraction, nerve transmission and blood clotting. It works in tight balance with magnesium for proper muscle function.
Chloride
Works with sodium to maintain fluid balance and is a component of stomach acid (hydrochloric acid). Typically sufficient from dietary sodium chloride (salt) without additional supplementation.
When do you actually need an electrolyte supplement?
For most people living sedentary lives in a temperate climate eating a balanced diet, food provides sufficient electrolytes for daily function. Supplementation becomes genuinely useful in specific circumstances: regular exercise - particularly sessions over 60 minutes or in the heat; following a low-carb or ketogenic diet (which increases electrolyte excretion through the kidneys); during menopause, when hot flushes and night sweats cause additional fluid and electrolyte losses; during illness involving vomiting or diarrhoea; or in very hot weather.
Signs you may be low in electrolytes
- Muscle cramps - particularly during or after exercise
- Fatigue and low energy despite adequate sleep
- Headaches, particularly after exercise
- Brain fog and difficulty concentrating
- Dizziness, particularly when standing up quickly
- Irregular or strong heartbeat
- Constipation or poor digestive function
For those who exercise regularly, follow a low-carb diet, or are navigating menopause, an electrolyte supplement is a worthwhile addition. Kollo Electrolytes+ Advanced Hydration provides a balanced electrolyte profile in a convenient sachet format. For more specific guidance, read our guide to electrolytes and exercise and our guide to electrolytes and menopause. For skin, hair and joint support alongside hydration, read our complete guide to liquid marine collagen.
Kollo Health was co-founded by Jenni Falconer - TV presenter, Smooth Radio breakfast host, ten-time London Marathon runner and host of the RunPod podcast. Read her story and why she created Kollo.
