Best Electrolyte Drinks for a Marathon

Training for and racing a marathon places huge demands on your body. Over 26.2 miles, you are not just burning through carbohydrate stores, you are also losing significant amounts of fluid and key electrolytes through sweat. Get hydration wrong and you risk cramps, fading pace, headaches and a tough final 10K.

The right electrolyte drink helps you maintain fluid balance, replace sodium losses and support consistent performance from the start line to the finishing straight. Here’s what to look for, and some of the best options for marathon runners.

Why Electrolytes Matter Over 26.2 Miles

When you sweat, you primarily lose sodium, along with smaller amounts of potassium, magnesium and calcium. Sodium is the key player for endurance athletes. It helps regulate fluid balance, supports nerve function and plays a role in muscle contraction.

During a marathon, especially in warmer conditions or if you are a salty sweater, sodium losses can be substantial. Replacing fluids alone is not enough. Drinking plain water in large amounts without electrolytes can dilute blood sodium levels, which can negatively impact performance and, in rare cases, health.

A good marathon electrolyte drink should:

• Provide meaningful sodium per serving
• Be easy on the stomach
• Mix easily and taste palatable over several hours
• Fit into your wider fuelling plan

Tablets vs Powders for Marathon Running

Both hydration tablets and powders have a place in marathon preparation.

Tablets are lightweight and convenient for travel or race expos, and are easy to drop into a bottle of water. Powders offer more flexibility in dosing and often allow you to scale sodium intake more precisely.

In training, it is worth experimenting with both to see what sits best with you. On race day, simplicity usually wins. Whatever you choose, practise with it during your long runs.

Here are some great options for a marathon:

STYRKR SLT07

STYRKR SLT07 Hydration Drink Tablets are engineered for endurance athletes who demand effective, convenient and stomach-friendly hydration. They use a quad-blend hypotonic formula that mirrors the natural sweat profile, helping to replace the electrolytes you lose during prolonged effort.

For marathon runners, their portability is a major advantage. Easy to carry and quick to dissolve, they are ideal for travelling to races or adding to your bottle pre-start.

SiS GO Electrolyte Powder

SiS GO Electrolyte Powder is a scientifically formulated sports drink designed to fuel performance and support hydration during endurance activity. It combines a fast-acting carbohydrate source with essential electrolytes to keep you energised and hydrated during sustained efforts.

It is easy to mix and gentle on the stomach, which is critical when you are pushing marathon pace for several hours. This type of drink works particularly well in long training runs where you want to rehearse race-day fuelling in one simple bottle.

226ERS Hydrazero

226ERS Hydrazero is a fast-acting, sugar-free hypotonic electrolyte drink designed to support hydration and mineral balance during and after intense physical activity. It delivers 500mg of sodium per serving, helping to combat the losses that naturally occur through sweat during long-distance running.

Because it is zero sugar and naturally sweetened with stevia, it is ideal for marathon runners who prefer to separate hydration from their carb intake. Hydrazero allows you to control your sodium intake without overloading your stomach late in the race.

FAQs

How much sodium should I aim for during a marathon?

Many runners need between 300 and 800mg of sodium per hour, but this depends heavily on individual sweat rate and conditions.

Is it better to combine carbs and electrolytes in one drink?

It can simplify your strategy, but some runners prefer separating hydration and fuel to reduce stomach discomfort. Test both approaches in training.

Do I still need electrolytes in cool weather?

Yes. Even in cooler conditions you lose sodium through sweat. The volume may be lower, but electrolyte replacement still supports fluid balance and performance.

Summary

Electrolyte drinks play a vital role in marathon performance. Replacing sodium and fluids effectively helps maintain pace, reduce cramp risk and support endurance through the final miles.

Whether you prefer a hypotonic tablet, a dual-action carb and electrolyte drink, or a sugar-free hydration mix, the best approach is the one you have tested and trusted in training.