The hardest part of building a hybrid training app (so far)

When we set out to build a hybrid training app, we thought the toughest challenge would be technical: writing code to sync with wearables, designing slick interfaces, stitching together video demonstrations. Those were hard, but they were solvable with time and talent. The real challenge turned out to be something much more human: reconciling two very different mindsets and translating that into a piece of software people would actually trust with their bodies.

Hybrid people live in two worlds. One day they’re chasing kilometre splits, the next they’re going after a new squat PR. Their calendars are packed and their goals are ambitious. Creating an app for them meant building a bridge between communities that have long been suspicious of each other. Runners worry that lifting will slow them down; lifters fear that too much cardio will eat away at muscle. We had to convince both that not only can they coexist, they can thrive together. Designing training plans that balance these competing demands is harder than it sounds. It’s not just a matter of alternating run days and lifting days. How heavy can you squat and still have fresh legs for intervals two days later? How many tempo miles can you handle in a week without wrecking your knees for plyometrics? Our early prototypes looked like complicated spreadsheets, because that’s essentially what they were. They worked in theory, but no one wants to open a spreadsheet at six in the morning on their 5 inch iPhone.

It forced us to simplify without dumbing down. We found that the key was building around real lives, not idealised training logs. People have jobs, kids, travel, unpredictable work shifts. A static plan that tells you to run long every Sunday doesn’t care that you’ve got a wedding that weekend. So we learned to make our app flex. You can swap sessions, shorten a run, add a recovery days and adapt the program. That flexibility came from listening to beta testers who told us they needed permission to adjust without feeling like they’d “failed” the program.

Another surprise was how personal hybrid training is. Athletes differ wildly in their backgrounds and equipment: some have home gyms, others rely on park benches and dumbbells; some measure heart rate variability, others use the “I can still talk” test. We considered building algorithmic recommendations but realised that, at least for now, nothing beats the expertise of a coach who has seen hundreds of bodies adapt to training. That’s why we decided to keep humans in the loop, tailoring plans based on feedback rather than letting AI spit out generic advice across the board. And while we’re working on including more AI within our app, it will only be ever used to improve on what a coach could do, never a shortcut.

Then there’s data. Hybrid athletes love numbers—splits, weights, reps, heart rate zones—but too much data overwhelms. We spent months arguing about which metrics matter. In the end, we focused on the essentials: pace zones, suggested rep ranges for key lifts, effort ratings for HIIT. We’re still iterating, new features like load, adaptive pacing, but the goal is to provide clarity, not confusion.

Integrating with existing tools has been another hurdle. Runners use Strava, lifters use notepads, hyroxers use whiteboards and notes. Bringing all those data streams into one place is technically demanding and, frankly, a bit messy. But it’s essential if you want to give someone a holistic view of their training instead of a fragmented mosaic.

The hardest part, though, might be cultural. We’re asking people to change how they see themselves: to embrace being both strong and fast, to accept days where they feel slow in service of getting stronger tomorrow. Our app is as much about education and mindset as it is about sets and reps. We spend a lot of time writing explanations, offering context, helping athletes understand why a recovery run matters and why their sessions are structured in a particular way.

We’re proud of what we’ve built so far, but we’re also humbled. Hybrid training is still young, and building tools for it means constantly learning. There are features we’ve shelved because they didn’t work, ideas we’ve abandoned because they felt gimmicky. The hardest part isn’t the technology-it’s staying true to a philosophy that’s both ambitious and sustainable. Making sure the app empowers people to chase big goals without burning out or getting hurt is a balance we’re still perfecting.

If you’re a hybrid athlete reading this, know that your feedback has shaped everything we do. Every time you tell us a workout was too long, or that you loved the mix of intervals and tempo’s within your block, we take note. The hybrid movement is redefining what it means to be fit, and building an app worthy of that movement is the challenge of a lifetime.

All your training in one place. Milo - Co-Founder of Edge