Cluster Dextrin vs Maltodextrin: What Actually Fuels Performance
At Hummingbird Fuels, we believe fueling should be simple, effective, and grounded in real science. In our Fuel Science Corner, we sit down with food scientist Richard to answer common questions athletes have about what is in their bottle and why it matters.
One question we’ve seen buzzing around the internet is: cluster dextrin vs maltodextrin. Which one actually performs better during exercise?
Let’s break it down by structure, absorption, energy delivery, gluten content, and real-world use.
The Basics: What These Carbohydrates Really Are
Both cluster dextrin and maltodextrin are long chains of glucose. No matter which one you consume, your body ultimately breaks it down into glucose and uses it for energy.
As Richard explains:
“Both cluster dextrin and maltodextrin are made up of long chains of individual units of glucose. Once they’re broken down in your body, they eventually turn into glucose, which is then used by the body as a fuel source.”
From a calorie standpoint, they are essentially the same. Both provide roughly four calories per gram. The difference is not calories, but how easily your body can access that energy.
Cluster Dextrin vs Maltodextrin Structure and Digestion Speed
The key distinction between cluster dextrin and maltodextrin is physical structure.
“Maltodextrin is basically just a long chain of single units of carbohydrate. Cluster dextrin is chemically altered so that the carbohydrates bond together. You end up with a ring structure of about 50-100 units of carbohydrate that form a little circle.”
That circular structure makes cluster dextrin harder for digestive enzymes to break down. Maltodextrin, with its straight chains, is more accessible and easier to digest.
Energy Delivery During Exercise
Slower digestion is often marketed as a benefit, but during training or racing, that logic does not hold up.
“What you’re really wanting during exercise is energy. You don’t need it to be mediated by the enzymatic functions in your pancreas and small intestine.”
Most athletes sip their fuel gradually throughout a workout. That behavior already creates steady energy delivery. Adding a carbohydrate that digests more slowly only increases digestive workload at a time when blood flow is prioritized to working muscles.
This becomes especially important when athletes are pushing higher carbohydrate intakes.
If you want a deeper breakdown of how much fuel your body can actually use before, during, and after long efforts, we cover that in our guide on carbs for a race.
Maltodextrin vs Sugar and Absorption Efficiency
Maltodextrin provides glucose only. That means it relies on a single intestinal transporter for absorption. At higher fueling rates, that transporter can become a limiting factor.
Sugar, or sucrose, naturally contains glucose and fructose in a one to one ratio. This allows the body to use multiple transporters at once and improves total carbohydrate absorption.
That is why many endurance fuels pair maltodextrin with fructose. The goal is not complexity, but efficient delivery of usable energy.
Is Maltodextrin Gluten Free?
Yes. Maltodextrin is gluten free. Maltodextrin is typically derived from corn or tapioca, neither of which naturally contain gluten. The same is true for cluster dextrin and sugar. Gluten would only be present if there were cross contamination in the supply chain.
For athletes who avoid gluten, choosing properly sourced and tested products matters.
Calories and Real-World Use
Calories in maltodextrin and cluster dextrin are essentially identical. What matters more is how reliably those calories turn into usable energy during exercise.
Maltodextrin, especially when combined with fructose or used alongside sucrose, delivers fast, predictable fuel that athletes tolerate well over long durations.
Cluster dextrin may have a place in non exercise contexts where slower digestion and satiety are desired. During endurance training and racing, it offers no clear performance advantage.
The Takeaway for Athletes
Effective fueling does not need to be complicated.
For endurance athletes, the priorities are clear energy availability, efficient absorption, and gut comfort. Carbohydrates that are easy to digest and easy to absorb consistently perform best during training and racing.
That is why Hummingbird Fuels builds its products around simple, proven carbohydrate sources rather than slower digesting options like cluster dextrin. As Richard explains throughout the interview, athletes benefit most from carbohydrates that deliver energy quickly without placing extra strain on the digestive system. This approach supports higher fueling rates, steadier energy, and better tolerance during long efforts.
You can feel the difference in our high carb drink mix for athletes, made with natural ingredients for clean taste, easy drinking, and reliable, fast acting fuel when performance matters most.