Together with our partner Unbranded Sportsfuel, we're delving into the world of sports nutrition. In the Fast Food series , we share practical, well-founded knowledge about what your body needs to perform. In this second edition: how 60, 90, or even 120 grams of carbohydrates per hour—and the right proportions—make all the difference to your performance.
Based on the blog of Unbrandedsportsfuel :
In the previous parts of We explored the role of gels, bars, and carbohydrate ratios in fast food. Convenient fuel during exercise, but always with one challenge: how do you combine energy with sufficient fluid intake? That's where the isotonic sports drink comes in. This drink is more than just a thirst quencher: it provides both hydration and carbohydrates, in a form your body can absorb incredibly quickly. Exactly what you need to sustain strenuous efforts, whether it's a long run, a summer triathlon, or a challenging bike ride.
Why an isotonic sports drink is more than just a thirst quencher
When exercising, you use enormous amounts of energy in a short time and lose fluid and minerals through sweat. If you don't replenish these quickly and efficiently, you'll notice it immediately: heavy legs, less concentration, and declining performance.
An isotonic sports drink is specially formulated to prevent this. It prevents this by providing the right balance of fluids, carbohydrates, and electrolytes. Because its composition matches that of your blood, your body absorbs the drink very quickly. Isotonic sports drink is therefore not just a thirst quencher, but a tool that makes the difference between persevering or coming to a standstill, between exercising comfortably or fighting a losing battle.
Hydration + energy = performance booster
The function of an isotonic sports drink is twofold :
- Rapid moisture absorption : this prevents dehydration and maintains your thermoregulation. This is especially essential in warm conditions. However, don't underestimate moisture loss through breathing and perspiration in cold conditions; even then, efficient hydration remains important.
- Instant energy supply : Carbohydrates are crucial for keeping your muscles running. While gels and bars require extra effort, an isotonic drink provides energy without having to open a container, chew, or swallow while training or racing. In that sense, an isotonic sports drink is a shortcut: free carbohydrates with every sip.
Also read: Why carbohydrates are essential for energy and performance in endurance sports
Isotonic, Hypotonic & Hypertonic – What's the Difference?
Sports drinks can be divided into three categories: isotonic, hypotonic, and hypertonic. These categories are based on osmolarity , the concentration of dissolved particles relative to the amount of dissolved particles in our blood. This determines how quickly the different drinks are absorbed by the body:
Isotonic
- Composition : Approximately the same concentration of dissolved substances as our blood (~270–330 mOsm/L).
- Function : Rapid moisture and energy absorption.
- Use : Ideal for endurance sports.
Hypotonic
- Composition : Lower dissolved solids concentration than blood (<270 mOsm/L).
- Function : Absorbed even faster than isotonic drinks, but provide fewer carbohydrates and therefore less energy . Perfect for achieving extra-high fluid intake.
- Use : Perfect for shorter, intense efforts or sports in extreme heat where hydration is more important than energy.
Hypertonic
- Composition : Higher concentration of dissolved substances than blood (>330 mOsm/L).
- Function : Energy content (amount of carbohydrates) is high, but absorption is slower and can burden the stomach.
- Directions : Ideal after exercise or during endurance training to replenish glycogen stores. Not ideal during intense exercise, when fluid intake is also crucial.
In summary
- Isotonic = balance between hydration & energy (best during exercise).
- Hypotonic = maximum hydration (in heat or short bursts of exercise).
- Hypertonic = maximum energy, less fluid intake (endurance training)
The role of electrolytes
Performance-oriented sports drinks contain not only carbohydrates but also electrolytes. These small building blocks ensure the right balance in the body.
- Potassium : improved muscle function and nervous system support.
- Sodium : ensures that the body can retain moisture better.
- Magnesium : involved in energy production and reduces the chance of cramps during exercise.
- Calcium : ensures better muscle contractions
Together, these electrolytes ensure improved fluid absorption and more effective muscle function during exercise, provided the proportions are well balanced.
The basic ingredients of an isotonic drink: water, carbohydrates & electrolytes.
The base of an isotonic sports drink always consists of three elements: water, carbohydrates, and electrolytes. The carbohydrate component is often a combination of maltodextrin and fructose. The advantage of this combination is that the two sugars use different transport channels in the intestine, thus complementing each other.
- Maltodextrin is converted into glucose by the body and absorbed via the SGLT1 transporter. This is a fast-acting sugar and can be processed at a rate of up to 60 grams per hour.
- Fructose uses the GLUT5 transporter, which functions independently of SGLT1. It's the slow sugar variant and can absorb up to 30 grams per hour.
By cleverly combining these sugars, you use two absorption routes at the same time and your body can process a total of up to 90–120 grams of carbohydrates per hour.
The optimal ratio for this is approximately one part glucose or maltodextrin to 0.8 parts fructose (hence the often-seen ratio of 1:1.08). With this knowledge, you can also create your own sports drink by combining the 100% unbranded fructose with the 100% unbranded maltodextrin in the correct ratio.
Also read: Carbohydrate ratios in endurance sports: which ratio works when?
Iso80: when iso, when hyper?
The power of Unbranded Iso80 lies in the flexibility of the dosage.
- 30–40 grams of powder per 500 ml of water results in an isotonic drink, ideal during exercise: rapid hydration, immediate energy, and a composition that your body absorbs effortlessly. The carbohydrate content is isotonic, while the electrolytes tend slightly toward hypotonicity, which favorably stimulates fluid absorption.
- A full serving of 80 grams per 500 ml creates a hypertonic drink. This provides a maximum amount of carbohydrates, making it perfect for long endurance sessions or for replenishing glycogen stores before or after strenuous exercise.
The name Iso80 So, it refers to the product itself, but the ultimate application depends entirely on how you dose it . Iso80 combines the benefits of hydration, a smart carbohydrate mix (1:0.8), and electrolytes in one product, allowing you to tailor your strategy to your goal: a quick thirst quencher during the race or a powerful energy reserve for the long haul.
The Iso80 is now available from stock at Unbrandedsportsfuel . Check the webshop for flavors and great prices!