What Is an Isotonic Sports Drink and Why You Should Use It?

Endurance athletes, especially cyclists, don't leave home without their sports bottle. But perhaps you wonder, what exactly does that bottle contain?

Typically, it contains an isotonic sports drink.

But what is an isotonic sports drink, what are its ingredients, and what are its benefits?

In this blog we answer these questions.

What is an isotonic drink?

The isotonic drink, also known as sports drink, carbohydrate drink, or energy drink (not to be confused with caffeine-based energy drinks, such as Monster or Red Bull), is a beverage that contains water, carbohydrates, and electrolytes.

It's goal is to slow down glycogen consumption and replenish lost minerals aka electrolytes. In simple words, it provides your body with energy (carbohydrates) and allows it to function properly (electrolytes).

And what is glycogen?

Glycogen is glucose that your body stores in the muscles and liver. It is your body's main source of fuel during intense exercise, so an external source of fast-acting carbohydrates, such as glucose and fructose, is essential to slow down glycogen consumption. Once your glycogen stores run out, you will not be able to continue with your exercise.

Isotonic drink ingredients

Isotonic drinks primarily contain two main ingredients:

• carbohydrates,
• electrolytes.

The types and concentrations of carbohydrates and electrolytes largely determine your isotonic drink's efficiency.

Carbohydrates in an isotonic drink

During intense exercise, your metabolism goes up, but your digestion goes down. What does this mean? It means your body wants more energy, but it's ability to get it from food is drastically reduced.

For this reason, during intense exercise you need to intake simple sugars, such as glucose and fructose. Glucose has a very high glycemic index, which means your body can quickly absorb it and use it for energy even when your digestion is impaired.

To achieve maximum absorption, you should intake a combination of glucose and fructose, as this will allow you to use both carbohydrate transporters in your body and absorb up to 90 grams of carbohydrates per hour.

Many drinks contain maltodextrin instead of glucose. What's the difference?

Maltodextrin is a chain of glucose molecules that feels less sweet in your mouth and could, although further research is needed, lead to better absorption.

Also, technically speaking, maltodextrin is not considered a sugar, that's why supplements may (and have to) declare low sugar quantities when containing maltodextrin, but for all intents and purposes, maltodextrin is the same as sugar.

Electrolytes in an isotonic drink

During intense exercise, you will lose a lot of fluid with your sweat. This also means you will lose a lot of minerals aka electrolytes.

To sustain proper hydration, you need to replace these minerals as efficiently as possible, as minerals are responsible for pretty much everything that's going on in your body.

The best isotonic drinks contain a complex mix of minerals, such as sodium chloride, potassium, calcium, and magnesium. But if there is one mineral you should definitely replenish, it's sodium chloride aka salt. 

Also be mindful of magnesium. Because it's supposed to prevent muscle cramps, many supplements contain way too much of it. We recommend keeping your intake of magnesium during exercise at a minimum to prevent digestive issues.

Benefits of the isotonic drink

The main benefits of the isotonic drink are pretty straightforward.

• Get energy during exercise
• Stay hydrated during exercise

But there are also other, less obvious benefits of the isotonic drink you should definitely keep in mind.

• Providing your body with carbohydrates and electrolytes is the best way to prevent muscle cramps during intense exercise.
• By providing your body with an external source of energy, you also slow down glycogen consumption, which in turn reduces stress.
• Since long-term stress weakens your immune system, reducing stress improves your health and reduces chance of illness and injury.
• Since illness and injuries impair your ability to train, by reducing their occurrence you allow yourself to progress more consistently.
• Consistent progress allows you to realize your full athletic potential and become the best athlete you can be.

If you wonder whether you should use an isotonic drink when the situation calls for it, the answer is very simple. Yes. Yes, you should.

And this leads to the final question.

When to consume isotonic drinks?

You should consume an isotonic drink whenever your body is likely to deplete its glycogen stores.

Typically, this is any high-intensity exercise that lasts more than 90 minutes. For shorter exercise, an isotonic drink might not be needed.

While there is some merit to consuming isotonic drinks before exercise (for carbohydrate loading) or after exercise (for recovery), isotonic drinks are primarily used during exercise to provide your body with an external source of fast-acting carbohydrates to slow down glycogen consumption and increase energy levels and to provide electrolytes in order to sustain proper hydration.

If you engage in high-intensity exercise that lasts more than 90 minutes, you should consider using an isotonic sports drink.

Conclusion

The isotonic sports drink is a beverage that contains water, carbohydrates, and electrolytes.

Its main purpose is to provide energy and hydration during intense exercise. It is mostly used by endurance athletes, but all sorts of athletes may benefit from an isotonic drink.

There are many benefits to using an isotonic drink, such as increased energy levels, correct body functions, reduced stress, prevention of muscle cramps, and improved performance.

When choosing your isotonic drink, you should be mindful of its ingredients and concentrations, as a low-quality isotonic drink may lead to poor efficiency and digestive issues.

When you engage in high-intensity exercise that lasts more than 90 minutes, you should definitely consider using an isotonic drink.