Built by a coach, for anyone serious about getting stronger.

Hi, I’m Nate. The only job I’ve ever had is being a coach.

I founded Data Driven Athlete in 2010 to coach cyclists, and Durable Fitness more recently to coach strength training.

Across both, I’ve spent over 20 years using training software every single day. Building programs, reviewing data, sending feedback, watching form check videos, tracking progress.

Twenty years is a long time to use someone else’s tools.

Over those two decades, I’ve had a lot of conversations that started with “I’m sorry, the platform doesn’t quite do that.” I’ve felt the frustration of features that didn’t exist, customizations I couldn’t make, and workflows that worked for the software vendor’s vision but not for how I actually coach.

Every coach I know has these conversations. Most of us have given up on the idea that the perfect platform exists, and learned to work around the limitations of whichever one we picked.

For most of those 20 years, building my own platform wasn’t realistic. I’m a coach, not a software engineer. The gap between knowing what the right product should be and being able to actually ship it was too wide.

That’s changed.

AI has fundamentally shifted what’s possible for someone with deep domain expertise but without a traditional engineering background. Instead of relying on someone else’s vision of what a coaching platform should be, I’ve been able to focus 20+ years of coaching experience and thousands of hours of using training software into the exact app I want to deliver to my athletes, and the exact app I want to use myself as someone who’s still trying to get stronger every day.

That’s IronOS.

IronOS is me.

Just me. There is no team, no engineering department, no product committee, no investors steering the roadmap. I build, test, retest, shape, and refine every aspect of the app myself.

This is unusual for software, and it’s intentional. Every interaction in IronOS reflects exactly one person’s twenty years of coaching judgment, not a compromise between a designer’s mockup, an engineer’s preferences, and a product manager’s metrics. When you log a set in IronOS, you’re using something that one coach made the way one coach wanted it.

If something feels off, it’s because I haven’t fixed it yet. If something feels right, it’s because I sat with the problem until I figured out the right answer.

What this means for you

Every decision in this app comes from someone who has actually coached athletes through the workflow, and who has been on the other side as the athlete trying to log a set between rests. The warmup pyramids, the RPE-based autoregulation, the Durability Score, the way coach notes show up alongside the right exercise. None of these are guessed at. They’re the answers to specific frustrations I’ve spent 20 years sitting with.

If you’re an athlete, IronOS is built around the experience of training, not the experience of inputting data.

If you’re a coach, IronOS is built to work the way you actually coach, not the way a software roadmap thinks you should.

Get in touch

If you’re a coach interested in using IronOS with your athletes, reach out directly at nate@ironos.app. At this stage, every coach onboards with a real conversation, not a signup form.