2:1 glucose-fructose ratio: what science really says about endurance

2:1 glucose-fructose ratio: what science really says about endurance

INTRODUCTION

There is that moment during a workout when everything changes. Until then, everything was going well. Your legs were responding. Your pace was smooth. And then, without warning, your energy drops. Everything starts to feel heavy. Your mind begins to bargain.

Many people explain this moment as a lack of carbohydrates. And for a long time, the answer was simple: You need to eat more.

But in reality, the issue is more subtle. And above all, much more interesting...

The real problem: your body has a limit

These recommendations are often heard:

  • 30 to 60 g of carbohydrates per hour
  • 60 to 90 g/h for longer efforts

These figures don't come out of nowhere; they stem from a very concrete physiological constraint: When you consume glucose, it must be absorbed in the intestine via a specific

transporter: SGLT1 . And this transporter has a maximum capacity.

The result: even if you consume more carbohydrates, your body caps out at around 60 g/h. The rest remains in the stomach and can cause digestive problems.

It's like trying to get too many cars through a single lane: at some point, it gets blocked.

The scientific breakthrough: opening a second path

Researchers then made a crucial observation: what if we used a second "entry point"? This is where fructose comes in. Unlike glucose, it uses a different intestinal transporter: GLUT5. And suddenly, everything changes. 



Two fuels, two highways

By combining glucose and fructose:

  • You use two different absorption systems
  • You reduce intestinal saturation
  • You increase the amount of energy actually available

Concrete result: your body can absorb up to 90 g of carbohydrates per hour , 

Le facteur que personne ne vous dit

Deux athlètes peuvent suivre exactement la même stratégie… Et avoir des résultats complètement différents. 

Pourquoi ? Parce que tout se joue aussi dans l'intestin. Tolérance digestive, habitudes, intensité de l'effort… Votre capacité à absorber les glucides est personnelle et entraînable. 

Le vrai danger : tomber en panne

Même avec une stratégie parfaite, votre corps dépend aussi de ses réserves internes.

Le glycogène, est votre batterie :

  • Environ 300 à 500 g dans les muscles
  • 80 à 120 g dans le foie

Total : entre 400 et 600 g

Mais pendant un effort long, cette réserve diminue progressivement. Et quand elle s'épuise :

  • La puissance chute
  • La concentration diminue
  • Le fameux « mur » apparaît

So, how much should one consume?

So, how much should you consume?

Today, the recommendations are quite clear:

  • 1.5-hour effort → 30 to 60 g/h
  • Effort lasting more than 2.5 hours → 60 to 90 g/h
  • Experienced athletes → up to 90–120 g/h

But there is one essential nuance. It’s not what you consume that matters. It’s what you absorb . 

The gut: the new training ground

This is probably the most interesting development in recent years. Your 

digestive system can be trained. 

Gradually increasing your intake helps:

  • Improve absorption
  • Reduce digestive issues
  • Achieve higher intakes

Today, some athletes tolerate up to  120 g/h . But it doesn’t happen overnight.

Concretely, how do you do it during training?

A simple strategy:

  • Consume regularly
  • Don’t wait until you’re tired or hungry to eat
  • Spread your intake out over time

For example:

  • Every 30 minutes → approximately 60 g/h
  • Every  20 minutes → close to 90 g/h

The idea isn’t to “save yourself” with a gel, but to avoid needing one.

Why is the 2:1 ratio a reference?

Because it provides:

  • Good absorption
  • Better digestive tolerance
  • Easy use in the field

It's not perfect, but it's reliable. That's why we created jelyly gels with a 2:1 ratio.

Available in 3 flavors: yuzu lemon, neutral, and wildberry*  they contain: 

  • 35 g of carbohydrates 
  • 200 mg of sodium 
  • *80 mg of caffeine for the wildberry flavor

IN CONCLUSION

Key takeaways 

If we simplify as much as possible:

  • Glucose alone is limited
  • Fructose makes it possible to increase absorption
  • The 2:1 ratio is effective, but depends on digestive tolerance
  • Most athletes perform between 60 and 90 g/h

But above all: nutrition is no longer a  detail , it is a performance lever. 

And ultimately…

The real turning point comes when you understand this: You don't eat to react to fatigue,  you eat so that it never happens.