Next-Gen Endurance Nutrition: The Science Behind SiS Beta Fuel

26th Nov 2025

Next-Gen Endurance Nutrition: The Science Behind SiS Beta Fuel

SiS Beta Fuel combines maltodextrin and fructose in a scientifically proven 1:0.8 ratio to enhance carbohydrate absorption and endurance. Enables athletes to consume up to 120g carbs/hour without gastrointestinal issues. Now available in drinks, gels, chews, and recovery blends for complete fuelling support.

The Evolution of Endurance Fuelling

For elite endurance athletes, carbohydrate delivery can make or break performance. In 2018, Science in Sport (SiS) launched Beta Fuel, a breakthrough in sports nutrition that shifted the boundaries of what was possible for energy intake during long-duration exercise. Backed by scientific validation and refined through collaboration with world-class teams, Beta Fuel has since evolved into a range that redefines optimal fuelling.

Understanding the Science: Why Dual Carbohydrates Matter

During endurance efforts, your body relies heavily on carbohydrate oxidation to sustain energy. The challenge? A single carbohydrate source like maltodextrin maxes out at about 60g/hour. By introducing fructose absorbed via a separate transporter SiS Beta Fuel enables the body to utilise up to 120g of carbs per hour efficiently.

This dual-carb system dramatically reduces reliance on the body’s glycogen stores, delays fatigue, and enhances sustained performance.

From 2:1 to 1:0.8 The Carb Ratio That Changed the Game

SiS Beta Fuel's original 2:1 maltodextrin-to-fructose ratio was good. But the new 1:0.8 formulation is a game-changer:


  • +17% in carbohydrate oxidation
    +3% in average sprint power
  • +12% in carb absorption efficiency
  • Reduced gut discomfort and nausea

This subtle yet significant shift means athletes can now push harder for longer with less digestive strain.

Breaking It Down: The SiS Beta Fuel Range

SiS Beta Fuel Powder

Delivers 80g carbs per serving in a neutral pH, isotonic formula to minimise GI stress. Available in Orange, Strawberry & Lime, and Red Berry.

SiS Beta Fuel Gels

Each gel packs 40g carbs in the same 1:0.8 ratio. Also available with added nootropics like L-theanine and Cognizin® to sharpen focus and alertness during prolonged efforts.

SiS Beta Fuel Chew Bar

Offers 40g carbs (7g per chew), making fuelling flexible and palatable. Unique texture and flavours (Orange, Lemon) help prevent taste fatigue.

SiS Beta Recovery

Pairs 60g carbs (1:1 ratio) with 30g whey protein and BC30™ probiotics for comprehensive post-exercise recovery. Targets both liver and muscle glycogen replenishment.

Tested at the Limits: 120g/hr Study Findings

In a landmark study, athletes consumed 120g/hr of SiS Beta Fuel using combinations of powder, gels, and chews. The results:


  • 50% of total energy came from SiS fuel after 3 hours of effort
    No performance decline or carb-to-fat crossover
  • 1.5g/min carb oxidation highest ever recorded
  • No stomach upset reported

This redefines fuelling expectations in elite sport.

Practical Fuelling Tips for Athletes

  • Start with 80-90g/hr during training to adapt gut
  • Mix product formats (e.g., gel + chew) to avoid flavour fatigue
  • Save nootropic gels for high-effort end stages
  • Use Recovery immediately post-session for optimal repair

Unleash Your Potential with Beta Fuel

With a decade of research, elite testing, and real-world victories, SiS Beta Fuel is more than a supplement; it's a performance revolution. Whether training for a marathon, cycling stage race, or Ironman, SiS offers the most advanced and complete fuelling strategy available.

Frequently Asked Questions:

1. How much SiS Beta Fuel should I consume per hour?

Start with 80-90g/hour and gradually build to 120g/hour based on training adaptation.

2. Is SiS Beta Fuel suitable for sensitive stomachs?

Yes, the isotonic formula and optimal carb ratio minimise GI distress.

3. What makes the 1:0.8 ratio better than 2:1?

It increases carb oxidation, reduces nausea, and improves power output.

4. Can I combine the different Beta Fuel formats?

Absolutely. The powder, gels, and chews are designed to work together seamlessly.

5. When should I use the nootropic gel?

In the later stages of long training or races when mental fatigue sets in.

6. Is Beta Fuel Recovery necessary if I eat after training?

Yes, it ensures rapid glycogen and muscle repair with a precise nutrient blend.

7. What is BC30™ and why is it in Recovery?

It's a probiotic that supports gut health, protein absorption, and immunity.

Key Takeaways

  • 1:0.8 carb ratio enables higher carb absorption with minimal GI distress
  • Up to 120g/hr carb intake shown to be effective in elite athletes
  • Product range includes powder, gels, chews, and recovery blends
  • Scientifically validated to support endurance and recovery
  • Flexible format helps personalise fuelling strategies

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