Endurance Fuel vs. High Carb Fuel: Which Tailwind product should I use when?

• Carb Content & Sources: Endurance Fuel delivers 50g of carbs from glucose (dextrose), while High Carb Fuel packs 90g from a mix of glucose, maltodextrin, and fructose for higher intake and absorption.

• Best Use Cases: Endurance Fuel is ideal for lower-to-moderate intensity workouts, casual activities, or hydration boosts. High Carb Fuel is designed for high-intensity sessions, big race days, or long efforts where you need more energy per hour.

• Hydration Balance: Both formulas contain balanced electrolytes, but hitting higher carb targets with Endurance Fuel requires drinking more water to maintain hydration balance.

• Train Your Gut: If you’re aiming for high carb intake with HCF, build up gradually in training to avoid GI issues—and always test your fueling plan before race day.

We’re in a golden age of fuel and hydration, where every athlete has a number of options for piecing together their electrolyte, fluid and carbohydrate needs. But all that choice can come with some decision fatigue—how do you choose which fuel source is right for you on any given day?

The annoying answer is this: it depends. Every body is different, and a running nutrition plan that works for one athlete may not work for another. Variables like sweat rate, heat, sodium loss, weather and intensity are all factors that can make fueling feel like a moving target. These major differences aside, there are some helpful considerations when filling your bottles that will give you the best chance at success.

Carbohydrate needs: Depending on the duration and intensity of exercise, most athletes are shooting for somewhere between 60 and 90 grams of carbohydrates an hour (though some are pushing much higher!). Generally, the longer and more intense the exercise, the more carbohydrates you’ll want on board. And the more carbohydrates you consume, the more you’ll want to consider the source of those carbohydrates (glucose, fructose, etc.) for optimal absorption.

• Endurance Fuel has 50 grams of carbohydrates per serving in the form of dextrose (glucose). 

• High Carb Fuel has 90 grams of carbohydrates per serving in the varied forms of dextrose (anhydrous), maltodextrin and fructose to maximize carbohydrate intake.

*Note: When trying to hit those bigger carb numbers, we recommend increasing intake gradually over weeks of training to avoid potential gut problems. 

Activity level: The balanced combination of electrolytes and carbohydrates in Endurance Fuel is well suited for most activities, including casual hikes, rides, team sports, or even just for a hydration and fuel boost on a hot day. High Carb Fuel is specifically designed for bigger days and/or more energy demanding activities. Think endurance events, hill repeats, big workout days, etc. 

Hydration: Both our Endurance Fuel and High Carb Fuel have a balanced electrolyte formula for optimal hydration, so in order to hit higher carbohydrate numbers with Endurance Fuel you also need to be consuming a lot more water to keep that beautiful balance. This may or may not be possible (or necessary) depending on the context of your activity and your body’s needs. 

How Tailwind athlete and pro cyclist Ellen Campbell fuels up:

"While I love using both Endurance Fuel and High Carb Fuel on many different rides to maintain calorie and electrolyte intake, each product serves a different purpose for me! Typically, I use EF in my bottles as my fuel and electrolyte replenisher during endurance rides where the intensity is lower. Then for training days that require some higher intensity I use HCF! With higher intensity efforts, my body burns through carbs quicker so it’s important for me to maintain a high carb intake. This also applies to every single race I do! Whether it’s a 25 mile mountain bike race or a 200 mile gravel race, I have HCF in all of my bottles. So my little rule of thumb is, EF for endurance days and HCF for high intensity days!”  - Ellen

A Tailwind fuel tool cheat sheet:

Endurance Fuel:

• For when you need electrolytes plus energy.

• Great for fueling moderate activity or anytime you need a hydration boost.

High Carb Fuel

• For when energy demands are high, and you need extra gut-friendly carbohydrates plus electrolytes.

• Great for before and during endurance events, high intensity activities or big training days. 

As always, we recommend experimenting with both Endurance Fuel and High Carb Fuel before relying on one or the other for a big event or race. That way, you can feel confident in meeting your own body’s unique needs for the effort at hand and can (quite literally) trust your gut.