High Carb Fueling with the Scientist Behind Carbs Fuel Gels

In Episode 118 of The Eat for Endurance Podcast, I’m joined by Aaron Gouw, an endurance cyclist and fellow Santa Cruz native (shout out to our hometown!) He also is the Co-Founder and Chief Product Officer of the sports nutrition brand Carbs Fuel.

Aaron holds a Master’s in High Altitude Exercise Physiology, and is currently finishing his PhD in Human Bioenergetics, with a focus on how the body responds to exercise and fueling. Yeah, he knows his stuff.

What I loved most about this conversation was that it wasn’t just about science or product development (though we definitely get into both). Aaron also shares his own journey as a competitive athlete, from making nutrition mistakes as a cyclist in college to eventually learning how to fuel like a pro despite plenty of bumps in the road. 

In this episode, we dive into the evolving science behind high carb fueling, how Aaron's personal fueling strategy has changed over the years, and what it's like to research and create an endurance gel from start to finish in your kitchen.

Aaron is on a mission to make high-carb fueling more effective and accessible for endurance athletes, with the 50g Carbs Fuel gel that retails for just $2 (definitely one of the best value gels on the market). Whether you’re new to high carb fueling or a nutrition nerd like us, this episode is packed with practical fueling advice and behind-the-scenes stories.

FYI: This episode is NOT sponsored by Carbs Fuel. I personally enjoy their gel (among others) and love that it's affordable, but I encourage you to try lots of different products to see which ones work best for you!

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From Beginner Cyclist to Carbs Fuel Co-Founder 

Aaron enjoyed football, soccer, baseball, track and other sports during high school. Once in college at UC Davis, he got into cycling and started to take it more seriously.

Like many endurance athletes, he had no real fueling plan on the bike. On a typical four-hour ride, he'd pack one Clif Bar and two bottles of water. No wonder he often felt terrible by the end!

Aaron shared a story about a particularly brutal ride through Big Basin State Park with over 8,000ft of climbing where he bonked so hard that he could barely make it home. He had forgotten to bring two Clif Bars with him that morning, but decided not to turn around to get them because he thought a banana and two hard-boiled eggs would be “enough.” 

Let’s just say… they were not. 

Creating an Endurance Gel

After a lot of trial and error with his own fueling, Aaron’s intrigue for endurance nutrition only grew. Fast-forward several years, and Aaron found himself diving deep into the research behind performance fueling. 

At the time, sports nutrition wasn’t getting as much attention in the cycling world as it does today. Most of his peers were focused on FTP and power zones, not carb intake. Fueled by both academic knowledge and his lived experience as a competitive cyclist trying to train on a tight budget, he started asking, “why aren’t more companies offering affordable, high-carb products?”

That question sparked the founding of Carbs Fuel, alongside his friend and co-founder Gabe Peterson.

The research and development process began right in Aaron’s kitchen. He tested different types of maltodextrin, experimented with glucose-to-fructose ratios, and played around with texture and flavor. It took nine months and more failed batches than he can count (including one that hardened into literal rock candy during shipping), but he eventually nailed down the right formula and Carbs Fuel gels were born.

The Science of High Carb Fueling & Where It’s Headed

Over the last decade, there’s been a pretty significant shift in the recommended grams of carbs per hour needed to fuel endurance athletes properly, from 30-90g/hour of carbs to 90-120+g/hour, especially among elite athletes.

Aaron and I both agree that more isn’t always better. Here’s what we know from the research:

• The gut can adapt to higher carb loads over time, which is a process known as gut training

• A mixture of glucose and fructose (e.g. a 2:1 ratio) supports higher carb absorption

• Studies show that individual tolerance varies widely, and personalization is essential

The research continues to evolve and we still need more data to back up potential differences in fueling needs based on body size and gender. However, the trend is clear: fueling with more carbs, whatever that means for you, improves performance in endurance events. 

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Which is Best: Gels, Solids, or Sports Drinks? 

One common question that Aaron and I both get asked often from clients is whether they should use a gel, sports drink, or solid food to fuel endurance activities. 

The short answer is, it depends. I know, sorry - a dietitian's favorite response!

Research shows that carb oxidation rates are similar across gels, drinks, and chews, as long as you’re getting the right amount and type of carbs. 

Rather than stressing over the “best” type of fuel, consider this instead:

• Your sport and intensity (solids may be harder to tolerate at higher efforts)

• Your personal GI tolerance and what works best for ou

• Your hydration strategy (if you’re drinking plain water, you may need sodium from another source)

  
  

Put simply… don’t over complicate it. Fuel your body with what feels good to you and supports your goals (even if it’s not the same as your running buddy or cycling crew).

Performance Nutrition Isn’t One-Size-Fits-All

One of the themes of our conversation (and one I talk about constantly on this podcast) is that nutrition isn’t one-size-fits-all. It depends on your body, nutritional needs, training intensity levels and duration, and more.  

Some athletes thrive on 100+ grams of carbs per hour. Others do just fine with 50–60g. 

What matters is that you practice fueling consistently and take the time to figure out what works for you and what you're setting out to do.

That might mean ignoring the latest trends (like high carb fueling), and figuring out what you really need to work on. Oftentimes, there are major gaps in everyday nutrition or other performance nutrition basics that need to be addressed first.

As Aaron put it, “fueling isn’t just about eking out the best performance in your workout...It’s about being a contributing person after you finish. You want to be able to help your partner, clean the house, or just feel good the rest of the day. That’s where proper fueling really makes a difference.”

To me, that’s what it’s all about.

Key Takeaways

• High carb fueling can improve performance, but only if it fits your needs and tolerance

• Carbs Fuel gels are a simple and affordable way to get 50g of carbs in

• Gut training and personalization are key for successful long-term fueling

• The right fueling strategy is the one you can actually stick with consistently and that makes you feel your best for training and life

Dial In Your Fueling With Online Nutrition Coaching

If you need help with your performance nutrition or if you just want to establish a strong nutrition foundation in your daily life, I can help! 

As a Registered Dietitian and endurance athlete myself, I’ve worked with runners, triathletes, cyclists, and active people of all levels to fine-tune their everyday and performance nutrition for over ten years. I have a wide variety of services available to fit every budget. 

• Join my membership service, Fuel for Life Crew, for $30/month (cancel anytime)

• Check out my free nutrition downloads

• Fill out a new client inquiry form if you’re interested in 1:1 nutrition coaching

Let’s take the guesswork out of fueling so you can train, race, and recover with confidence.

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Disclaimer: All information provided is for educational and entertainment purposes only and is in no way meant to replace individual medical and nutrition recommendations.