Sport Drinks

Hydration guide: WHAT AND HOW MUCH TO DRINK

Most athletes focus on fueling with carbohydrates. Logical. But hydration is the silent performance killer. When your fluid balance is off, your body absorbs carbohydrates far less efficiently. In practice, dehydration can reduce carbohydrate absorption by 40 to 60 percent, increasing the risk of cramps, loss of power and early fatigue.

👉 Hydration calculator

Personalize your drink every hour.

Every body is different. And so is every challenge.

For a short one-hour bike ride, there is no need to overthink things. In most cases, simply using Pro Isotonic is more than enough. But when the effort gets longer or harder, a one-size-fits-all approach no longer works. By personalizing your sports nutrition, you can unlock up to 40 percent more usable energy and endurance when done correctly.

Below, we show you how to do exactly that.

 

  • Use Pro Isotonic sports drink as a base and add Pro Hydro & O.R.S if you  sweat more than usual due to heat, high sweat rates or indoor training, add 1 to 2 Hydro Sticks
  • You can also addPro Elite Carb Max sticks to your Pro Isotonic. This delivers a powerful energy boost using five different carbohydrates, turning your isotonic drink into ahypertonic formula with up to 140 g of carbohydrates per bottle.
  • Check out the  Hydration calculator
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What is the perfect isotonic?

Sports drinks come in every color, flavor and form. But looks mean nothing. What really matters is quality: how fast and how efficiently your drink restores energy, fluids and minerals. Here’s how to choose the right isotonic drink for your body and your effort.

  • At 3 percent dehydration, thirst kicks in.
  • At 2 percent dehydration, performance already drops.

That’s why we say: drink before you feel it. If you’re thirsty, you’re already behind. For maximum energy and fluid absorption, an isotonic drink is your foundation. If needed, you can always add a gel later for an extra push in the final phase.

1. What makes an isotonic a good sports drink?

Both sports drinks and isotonic drinks aim to replace fluids and minerals lost through sweating. The carbohydrates provide an additional source of energy.

The key difference lies in osmolarity. An isotonic drink has a sugar and salt concentration similar to that of the human body. This allows for fast and efficient absorption.

When a drink is not isotonic, absorption drops. Part of what you drink simply isn’t taken up by the body. An isotonic composition ensures you get enough nutrients, but never too much. Your body doesn’t have to waste energy on digestion or correction, leaving more energy available for what really matters: performance.

Hypertone, isotone, and hypotone

  • Hypertonic drinks have a higher concentration of dissolved particles than the human body. As a result, they are absorbed slowly and place extra stress on your digestive system. During exercise, they provide little usable energy. At best, you get a short spike that fades within minutes, often followed by discomfort or an energy dip. A classic example: cola.

  • Isotonic drinks match the body’s particle concentration, with an osmolarity of 280–320 mmol/L, allowing for fast and near-complete absorption. Most isotonic drinks contain 6–8 g of carbohydrates per 100 ml.

    Pro Isotonic delivers more usable carbohydrates per bottle, while remaining fully isotonic. More energy. Same fast absorption.

  • Hypotonic drinks have a lower concentration of dissolved particles than the body, which makes them very fast to absorb but also limits the amount of nutrients they provide. Examples include Isostar or Aquarius. While their rapid absorption is an advantage, the energy is quickly depleted, and with up to 6 g of carbohydrates per 100 ml, hypotonic drinks are often insufficient for sustained sports performance.

Always choose an isotonic carbohydrate-electrolyte formula. Only then do you get a sports drink that supports performance, absorbs efficiently and doesn’t let you down when it matters.

2. Ensure a varied mix of fast and slow carbohydrates.

Most isotonic sports drinks use only two carbohydrates, usually maltodextrin and fructose. That limits total energy delivery.

Elite athletes therefore choose drinks with four carbohydrates: maltodextrin and sucrose for sustained energy, combined with dextrose and fructose for fast uptake. This combination delivers high, stable energy levels and supports prolonged top performance.

That’s why the best isotonic sports drinks use 4 carbohydrates: maltodextrin and sucrose for steady energy, combined with dextrose and fructose for fast uptake. This mix delivers stable, high energy and is a strong sign of a well-built isotonic drink.

With Carb Max sticks, you add 5 extra carbohydrate sources to Pro Isotonic. Together, that gives you 6 different carbohydrates in one setup. More flexibility. More fuel. Built for long efforts.

The ideal isotonic sports drink for endurance athletes contains more than 30 grams of carbohydrates, distributed across four different types. Isotonic is often key to sustaining prolonged efforts.

3. Potassium and phosphorus are essential.

An imbalanced fluid balance leads to fatigue and cramps. Exactly what you want to avoid as an athlete. Your fluid balance is the engine that delivers energy. To keep it running, you need enough minerals. Potassium and phosphorus are lost through sweat and must be replenished.

So remember two basics: drink regularly, and make sure your isotonic sports drink contains sufficient minerals.

  • You sweat more than you think, and maintaining a stable fluid balance during exercise requires constant attention. Dehydration can’t be fixed by drinking a lot at once, and if your fluid levels drop too far, performance can fall apart quickly.

  • Thirst only appears when fluid loss reaches about 2 percent, but performance already drops from 1 percent dehydration. That makes thirst a delayed warning signal. Once you reach that point, catching up is difficult. The solution is simple: drink regularly and on time, even when you don’t feel thirsty.

  • Absorbing enough fluids requires sufficient minerals, and the reverse is also true. Without minerals, hydration simply doesn’t work. That’s why potassium and phosphorus are essential in an isotonic sports drink. They play a key role in fluid absorption and help maintain stable hydration levels during exercise.

4. A good isotonic drink is tasty and pH-neutral.

  • A neutral pH shows that your isotonic drink contains no added acids or aggressive flavorings. This makes it easier to digest and ideal for athletes with a sensitive stomach.

  • A good isotonic drink triggers a strong thirst reflex, encouraging you to keep drinking and ensuring adequate intake of fluids and minerals during exercise.

  • A good isotonic drink is never sticky in the mouth. A sticky feeling is a clear sign of low-quality carbohydrates.

  • A good isotonic drink should taste good. It should go down smoothly, or else you might not drink enough of it.
  • 3 different flavors: Minth-lime, Orange en Tropical.

5. What impacts the absorption of energy from drinks?

  • The amount you drink is the most critical factor. After that, the energy content of the drink determines how well you perform.

  • Drink 2 sips every 15 minutes instead of 4 sips every 25 minutes. Continuous replenishment has a significant impact.

  • Hypotonic drinks are absorbed the fastest. Isotonic drinks offer the best balance between absorption speed and sustained energy delivery. That’s why you should always start with an isotonic drink, and add an energy gel in the final 30 minutes if you need an extra push. You can use Pro Elite Carb Max to peak your carbohydrate intake for about an hour. Just don’t do this continuously for three hours, or you’ll compromise your fluid balance.

  • Mineral salts enhance fluid absorption and are essential for maintaining performance, especially when sodium levels drop due to heavy sweating.

  • Effort intensity matters: the higher the intensity, the lower your drinking rate. Use calmer moments during long efforts to drink enough and maintain stomach volume, so hydration doesn’t become a limiting factor later on.

6. This is how you discover your Hydration status

  • You can use a scale: weigh yourself before and after training and subtract the amount you drank during the session. The difference shows your fluid loss.

  • Urine test: use our chart to quickly check whether your fluid intake has been insufficient.