Performance Fueling

Performance Fueling explores the fundamentals of endurance energy and nutrition. Here you’ll find practical explanations of how carbohydrates, energy gels, and fueling strategies support sustained performance during training and racing.

These articles are part of our broader Fueling Science resource, where we break down endurance fueling without unnecessary complexity.
Flat lay of whole grain bread, oats, sugar cubes, a bowl of salt with wooden spoon, and a glass of water on the left, contrasted with fresh fruit, dates, gummy candies, and dripping honey on a wooden board on the right.
Glucose vs Fructose
Glucose and fructose use different intestinal transporters, SGLT1 and GLUT5, allowing blended carbohydrates to increase total absorption and oxidation during endurance exercise. Learn how multiple transportable carbohydrates may improve fueling... Read more...
Natural endurance fueling ingredients including honey, dates, sea salt, and water arranged on a light surface.
The Complete Guide to Energy Gels and Endurance Fueling
A complete, science-based guide to energy gels and endurance fueling, covering carbohydrate intake, ingredients, gut tolerance, caffeine use, and race-day strategy for endurance athletes. Read more...
Natural carbohydrate and electrolyte ingredients used in energy gels arranged on a neutral background.
What Is an Energy Gel and How Does It Work?
Understand what energy gels actually do in the body, how they’re absorbed during exercise, and why formulation matters for performance and gut comfort. Read more...
energy gel ingredients with honey as the primary carbohydrate source alongside electrolytes for endurance performance
Energy Gel Ingredients Explained: What Each One Does and Why It Matters
A clear, science-based breakdown of common energy gel ingredients, explaining how each one works in the body and why formulation matters for performance and gut tolerance. Read more...
Honey and salt shown as natural carbohydrate and electrolyte ingredients used for endurance fueling.
Honey vs Maltodextrin Energy Gels: What the Science Actually Says
A science-based comparison of honey and maltodextrin energy gels, examining performance, digestion, blood sugar stability, and gut tolerance during endurance exercise. Read more...
Subtle illustration of the human digestive system in neutral tones on a soft textured background.
Energy Gels for Sensitive Stomachs: What to Look For
A science-based guide to why energy gels cause stomach issues for some athletes, and how to choose formulations that support digestion, absorption, and race-day comfort. Read more...
Subtle countdown timer embossed into a neutral sandy background, symbolising timing during endurance running.
How Many Energy Gels Per Hour While Running?
A science-based guide to how many energy gels you actually need per hour, based on intensity, duration, gut absorption, and real-world performance evidence. Read more...
Caffeine sources and electrolyte drinks arranged on a neutral background with coffee beans.
Caffeine Energy Gels: How Much Is Too Much?
A science-based guide to how much caffeine endurance athletes actually need, how caffeine gels affect absorption, and where performance gains turn into side effects. Read more...
Natural carbohydrate foods commonly used for endurance fueling, including honey, rice, oats, dried fruit, and energy bites arranged on a wooden surface.
How to Fuel a Marathon With Natural Carbs
A practical, science-based guide to marathon fueling, explaining how much carbohydrate you need, when to fuel, and how to use natural sources to sustain race-day performance. Read more...