The Science of the Sweat: A Decade of Disrupting Endurance Nutrition

An Interview with Jan and Michelle Buchegger

As Fixx Nutrition approaches its tenth year, the brand has moved from a ‘niche’ Australian secret to a staple in the locker rooms of the English Premier League and on the hydration stations of the world’s most prestigious marathons. We sat down with founders Jan and Michelle to discuss the evolution of the brand, the "guinea pig" testing phase of their products and why the "all-natural" path is the only one worth taking.

A Grounding Year: Fixx in 2026

Q2: We’re at the start of 2026. Looking at the business today, what does the snapshot look like for Fixx Nutrition?

Michelle: It’s a grounding year for us. We are into our fifth year of partnering with the Gold Coast Marathon - our hometown race - and we’ve taken on even more marathons globally. But 2026 is about building the core. We’re expanding our manufacturing team to support our expanded manufacturing site, allowing us to focus on the US and UK markets.

Jan: We’re also listening to the fans. We’re relaunching our cold brew espresso due to massive demand. But the philosophy remains the same: we fuel endurance. If you are training past that one-to-two-hour mark, we want to be the ones ensuring you don't "bonk" or cramp.

Michelle: And we do it naturally. If you’re doing the hard yards to make yourself feel better, why would you fuel yourself with something bad for you? We avoid preservatives and stick to plant-based options wherever possible. If athletes actually delved into the ingredients of what they put in their bodies, they’d be shocked.

The Anatomy of Fuel: Why "Simple" is Smarter

Q: Jan, your Fuel X and Fuel X Pro lines are famous for being "gut-friendly." Can you break down the thinking behind that formulation?

Jan: In the old days, everyone used complex carbohydrates like maltodextrin because it was cheap and supposedly "slow-burning." But we found that complex carbs are hard on the gut. You’d be five miles into a marathon and suddenly be looking for the nearest toilet.

With Fuel X, we used simple carbs - dextrose. It sounds counterintuitive, but simple carbs are easier to digest under stress. When you run, blood flow leaves your stomach to power your legs. If your fuel is too complex, it just sits there and causes havoc. By using a simple, corn-based carbohydrate, we ensure that even if you try our product for the first time on race day, you won't get an upset stomach.

Q: And the nutrition targets have changed, haven't they?

Jan: Dramatically. It used to be that 50–60 grams of carbs per hour was the goal. Now, elite athletes are targeting 100–120 grams. You can’t reach those numbers with complex carbs without destroying your gut. Our dual-fueling system makes those higher numbers achievable for the average punter, not just the pros.

The Athlete Lab: "Mysterious Bowls and Compulsory Testing"

Q2: One thing people might not realise is that you are the manufacturers. You don’t just outsource the recipe. How does a product go from an idea to the shelf?

Jan: (Laughs) It’s a long process - at least 12 months. I’ll come out of the lab with little clear bowls of mysterious contents and make the staff try them. It’s compulsory testing!

Michelle: We’ve had some interesting moments. Jan will come out saying, "This is the winner!" and we take one sip and realize nobody would ever drink it. Once we get it past the "staff phase," we send it to selected sponsored athletes our sponsored athletes. They are our guinea pigs. They tell us if it’s too sweet, if the packaging is wrong, or if they don’t like the taste. 

Jan: We also use outside experts and independent labs for a full analysis. We want our nutritional panels to be 100% accurate so athletes know exactly what they are getting. It’s "Created by Fixx, Tailored by Athletes."

H2 Electrolytes: Replacing the Minerals, Not Just the Water

Q: Explain it to me like I'm five: what actually is an electrolyte, and why isn't a "zero-calorie" sports drink enough?

Jan: We classify electrolytes into four key minerals: Sodium, Potassium, Magnesium, and Calcium. When you sweat, you aren't just losing water; you’re losing these minerals. If you don't replace them, your muscles stop firing correctly, and you cramp.

The problem with "zero-calorie" drinks is that they provide the minerals but no energy. You can’t run a 50k race on zero calories. You’ll be in a deficit, and you’ll "bonk." We combine the electrolytes with the fuel so you’re replacing the minerals and the energy simultaneously.

The Gel Evolution: Moving Away from "Shitsticks"

Q: You had a nickname for the old style of energy gels...

Jan: Yeah, we used to call them "sh@#sticks" because they’d send you straight to the bathroom. The old gels were thick, gooey, and made of maltodextrin.

Michelle: With Gel X Pro, we looked at the science of the market leaders but decided we could do it better. We used a 1:0.8 carbohydrate-to-fructose ratio. Science used to say fructose was bad because it had to be processed by the liver, but we now know that in that specific ratio, it can be absorbed directly in the intestine.

Jan: We also made ours more liquid—a syrupy texture that doesn't require a liter of water to wash down. We added Alanine, which is an amino acid that helps regulate blood sugar, along with sodium so you don't get that massive sugar spike and subsequent crash.

The Recovery Ecosystem

Q: You’ve moved into a full "pre-to-post" race ecosystem. Why was a plant-based recovery range (Protein X) so important?

Jan: For endurance athletes, the ideal recovery is 20 grams of protein and 20 grams of carbohydrates. Most recovery drinks skip the carbs, but your body needs them to replenish glycogen stores.

Michelle: Making plant-based protein taste good was a challenge. Usually, the texture is horrible. But we’ve managed to get a smooth, palatable texture that includes electrolytes and Glutamine for gut health. It’s about making the best possible attempt for your body to recover so you can go again the next day.

The "Function Over Flavour" Philosophy

Q: Fixx is now being used in the English Premier League and by international cricket teams. Why are these elite groups gravitating to the brand?

Jan: Because it works. When we first exported to Korea, they were skeptical. They tested it extensively and told us, "Your product actually works, but it doesn't taste great." My response was: "I can make it taste like candy, and it won't work. Or I can make it functional."

Michelle: We obviously try to make everything delicious, but functionality is the priority. We use Stevia because it’s a natural sweetener. It might not taste exactly like a diet soda, but it doesn't have the harmful artificial chemicals that are now being linked to health issues. We choose the "natural" path every time.

Highlights and the Bucket List

Sean: Nine years in, what’s been the standout moment?

Michelle: Securing the Gold Coast Marathon partnership. Jan and I have run that race so many times. To see our product on that course in our hometown... that was a massive goal achieved.

Jan: For me, it’s the stories from the trail. I was once climbing a hill during a race, and a girl in front of me saw a guy cramping. She said to him, "You need some CrampFix; that's the best stuff in the world." She had no idea I was the owner standing right behind her. That inspires me every day.

Sean: And what’s left on the bucket list?

Jan: I’ve done Berlin and Chicago Marathons. I’d love to do New York or Boston as the other ‘majors’ (the Abbott World Marathon Majors). But my big dream? The Marathon des Sables; the race through the Sahara Desert. That’s been the goal for ten years.

H2 Fixx Nutrition: The 2026 Core Range (turn this into a graphic)