Isotonic Sports Drinks

Stay Hydrated and Energized With Isotonic Sports Drinks

Isotonic sports drinks, also known as carbohydrate drinks, are a great way to fuel your longer training sessions and boost your performance.

Whether you're running or cycling for hours, these isotonics will help you sustain high energy levels, prevent muscle cramps, and keep your hydration on point.

What Is an Isotonic Sports Drink?

Isotonic sports drinks are designed to replenish electrolytes lost through sweat and slow down glycogen depletion.

They contain 20–90 grams of carbohydrates per serving and essential electrolytes, such as sodium, potassium, calcium, and magnesium.

Carbohydrates provide steady energy to maintain performance and prevent energy crashes. Electrolytes support muscle function and hydration. Together, they help prevent muscle cramps and keep you performing at your best.

When Should You Use Isotonic Sports Drinks?

For workouts under 1 hour, your body has enough glycogen, so focus on replenishing only electrolytes to stay hydrated — no extra carbs needed.

For sessions over 1 hour, glycogen stores get depleted. Adding carbohydrates helps maintain energy and prevent muscle cramps. For most athletes, 45–60 grams of carbs per hour is sufficient. However, if you're a more serious endurance athlete, you can increase this to up to 90 grams per hour, depending on the intensity of your workout. For example:

• 1–2 bottles/hour of Nrgy Drink 45

• 1 bottle/hour of Nrgy Drink 90 

This applies when using sports drinks as your sole energy source. If combining with energy gels or bars, adjust intake to reach the recommended carbohydrate target.

What to Look Out for When Choosing Isotonics Sports Drinks

Main factors to consider are:

• source and quantity of carbohydrates

• type and amount of electrolytes

The best isotonic drinks combine different carbohydrate sources, such as glucose and fructose, to maximize energy absorption without causing digestive issues. Additionally, they offer a balanced mix of sodium, potassium, calcium, and magnesium to replace minerals lost through sweat.

If you're new to carbohydrate rich isotonic sports drinks, it’s important to train your gut to handle higher carb intake. Your digestive system needs time to adapt to processing carbohydrates during exercise, especially at higher intensities.

Start with drinks that have a lower carbohydrate content, and gradually increase your intake to reach the recommended 45–90 g of carbs per hour.

Also, never test a new sports drink during a race. Without proper adaptation, even the best drink can lead to digestive issues that could ruin your performance.

Beyond that, it’s all about personal preferences. The best isotonic drink is the one that suits your body and performance needs.

Which Isotonic Sports Drinks Are Available?

At 4Endurance, we offer a variety of isotonic sports drinks. Whether you're running or cycling, we have the right drink to keep you energized and hydrated.


Nrgy Drink 45:  It contains 45 grams of carbohydrates per serving and the advanced Nduranz Electrolyte Mix. Ideal for more intense training sessions.

Nrgy Drink 90: The most powerful drink we offer. It contains a whooping 90 grams of carbs per serving and the advanced Nduranz Electrolyte Mix. Ideal for races and the hardest training sessions.

Nrgy Drink Bicarb 45: Contains 45 grams of carbohydrates and sodium bicarbonate to fight muscle acidity. It is perfect for sprints, hill climbs, and shorter intervals.