Fuel and Flow with Jess

Electrolytes vs water for runners

When it comes to hydration, runners are often split between two camps. Stick with water, or reach for electrolytes. Electrolyte drinks have become increasingly popular, promising faster recovery, better performance, and superior hydration. But are they really necessary for every training session?

Let us break it down.

What are electrolytes and why do they matter?

Electrolytes are minerals, including sodium, potassium, magnesium, phosphate, and chloride, that carry an electric charge in the body. They regulate fluid balance, support muscle contraction, aid nerve signalling, and play a vital role in performance and recovery.

Although you might think of electrolytes as something that comes in a powder, tablet, or sports drink, you will also find them in a balanced diet, absorbed through the foods you eat.

During exercise, especially in hot or humid environments, you do not just lose water through sweat, you lose electrolytes too. The primary one lost is sodium, but depending on your physiology, for example if you are a salty sweater, you may also lose significant amounts of potassium and magnesium.

Dehydration and performance

Most of us have felt the effects of hydration at some point. Fatigue, cramping, dizziness, or a noticeable drop in pace. Even relatively small fluid losses can impair endurance, strength, and focus.

This is where electrolytes can sometimes make the difference between finishing strong and fading early.

When electrolytes make sense

Electrolyte drinks are not necessary for every workout. If you are heading out for a 30 to 45 minute run, or lifting in an air conditioned gym, water is usually more than enough.

There are key situations where electrolytes provide a performance edge:

• Endurance training or competition over around 75 minutes, particularly running, cycling, or team sports.
• Hot or humid environments where sweat rates are higher and more sodium is lost.
• Salty sweaters who notice white salt marks on clothing or skin after training.
• Back to back training sessions where recovery time is short.
• Illness recovery, for example after vomiting, diarrhoea, or fever, where fluids and minerals are lost quickly.

In these cases, an electrolyte supplement can help maintain fluid balance, reduce cramping, and support faster recovery.

When water is enough

For everyday training under an hour, water is still the foundation. It is widely available and keeps you hydrated without unnecessary extras. If you are eating a balanced diet, you are already getting plenty of electrolytes from foods like fruit, vegetables, dairy, and whole grains.

Can electrolytes be harmful?

Electrolyte drinks are useful tools, but they are not designed to replace water entirely. Overusing them, particularly when you are not actually losing high amounts of sodium and potassium, can backfire.

Potential issues include:

• Excess sodium intake, which may raise blood pressure in sensitive individuals.
• Too much potassium, which may cause gastrointestinal discomfort, nausea, or diarrhoea.
• Hidden sugars, which are not ideal for low intensity or short sessions where you do not need extra fuel.

For runners, reading the label is key. Look for products with a balanced blend of electrolytes, not just sodium, and avoid those overloaded with sugar unless you specifically need the carbohydrates for fuel.

Practical hydration tips for runners

• Before training: aim for roughly 250 to 500 millilitres of water one to two hours beforehand.
• During training: use water for sessions under 60 minutes. For longer or hotter sessions, add 30 to 60 grams of carbohydrates and electrolytes per hour.
• After training: aim to replace around one to one and a half times the fluid you lost. If sweat loss was high, include electrolytes in your recovery drink.

Featured electrolytes mentioned in this article

• Trainade Hydration
• Tailwind Endurance Fuel
• Skratch Labs Hydration Sport Mix

The bottom line

Think of electrolytes as a performance strategy, not an everyday drink. For most standard training sessions, water will do the job. For long sessions, hot conditions, back to back sessions, or race day, the right electrolyte plan can help you perform at your best.

Need help with your hydration strategy?

If you are unsure when to use electrolytes, how much you need, or which products are right for you, working with a sports nutritionist can take the guesswork out. Together you can build a simple, realistic hydration plan that supports your training and racing.

Book a sports nutrition chat with Jess

Book a chat today and feel more confident about your hydration on and off the run.