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.
Honey comb and honey on a plain background
Best Natural Energy Gels for Running
Natural energy gels are becoming a preferred choice for endurance athletes. Learn what makes them effective and how to choose the best one. Read more...
Natural carbs, dates and oats on a neutral background with processed carbs, sugar
Natural vs Processed Carbohydrates in Endurance Fueling
Does carbohydrate processing affect endurance fueling? Learn how natural and processed carbohydrate sources differ in digestion, absorption, and athlete tolerance during prolonged exercise. Read more...
Legs running on sand
When to Take Energy Gels During a Run
Fueling isn’t something you fix mid-run. It’s something you plan. Learn exactly when to take energy gels to stay ahead of fatigue, maintain performance, and finish strong. Read more...
Common Marathon Fueling Mistakes
Common Marathon Fueling Mistakes
Marathon fueling often fails due to small, preventable mistakes. Learn the most common fueling errors runners make and how to build a consistent strategy that supports steady energy and digestive... Read more...
Male legs running on neutral sand background
How Many Carbs Per Hour for Running?
How many carbohydrates should runners consume per hour? Learn the fueling guidelines used in endurance sports and how athletes structure carbohydrate intake during long runs and races. 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...
Honey digestive tract with salt crystals
Training the Gut
Training the gut is a key component of endurance fueling. Repeated carbohydrate intake during training may improve absorption capacity and reduce gastrointestinal discomfort by increasing intestinal transporter activity and tolerance... Read more...
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 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...