Electrolytes

What Are Electrolytes?

Electrolytes are minerals that carry an electrical charge in your body, including sodium, potassium, magnesium, and calcium. They regulate fluid balance, nerve signalling, and muscle contraction. When you sweat during exercise or go extended periods without eating (such as during intermittent fasting), you lose electrolytes that need to be replaced.

How They Work

Your muscles contract and relax through a carefully controlled exchange of electrolytes across cell membranes. When these minerals are depleted — through heavy sweating, prolonged training, or fasting — you can experience cramping, fatigue, headaches, dizziness, and reduced performance. Replacing them maintains hydration at a cellular level, which plain water alone cannot always achieve.

What the Research Says

The science on electrolyte replacement during exercise is well-established. For workouts lasting over 60 minutes or taking place in hot conditions, electrolyte supplementation improves endurance, reduces cramp incidence, and maintains cognitive function. The American College of Sports Medicine recommends sodium replacement during prolonged exercise as a baseline guideline.

For intermittent fasting, electrolytes are particularly important. During fasting, insulin levels drop, causing the kidneys to excrete more sodium and water. This is why many people feel lightheaded or get headaches when starting a fast — it is often an electrolyte issue, not a calorie issue.

What to Look For

The best electrolyte supplements are low in sugar and contain a meaningful dose of sodium (the primary electrolyte lost in sweat), along with potassium and magnesium. Avoid sports drinks loaded with sugar unless you specifically need the carbohydrates during endurance events. Look for products with at least 500-1000mg sodium per serving for heavy training or fasting use.

Who Should Take Them

People who train intensely (especially in heat), practise intermittent fasting, follow low-carb or keto diets, or experience frequent cramping. If you do light exercise and eat a balanced diet, you likely get enough from food.

DIY Electrolyte Drink

You do not need an expensive product. A simple recipe: 1 litre of water, 1/4 teaspoon salt (sodium), a squeeze of lemon (potassium), and a pinch of magnesium citrate powder. Cheap, effective, no sugar.

Vegan?

Electrolyte supplements are vegan-friendly. They are mineral-based and contain no animal products. Check labels for any unnecessary additives, but the electrolytes themselves are always plant-compatible.

Where to Buy

• Bulk Electrolyte Powder — from £6.99
• Amazon — LMNT Electrolyte Mix — from £24.99
• Myprotein Electrolyte Plus — from £9.99

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