About

Training is where we feel most alive. Just you, your breathing, and the rhythm of your own effort. Nobody else's session, nobody else's pace. Then you get home, open the laptop to dig into what you just did, and land on a dashboard that looks like it has not changed since the 1990s. It calls the session easy while your legs are still arguing otherwise. It scores your fitness on a percentile against strangers. The best, most personal hours of your week, handed back as numbers that could belong to anyone.

OSO was built by serious endurance athletes who got tired of translating other people's numbers into personal truth, and who wanted the read of a session to feel as connected and personal as the session itself. So the whole thing works as one piece, end to end: your devices connect once and every ride, run and swim flows in on its own, every number comes with the reasoning behind it, and the workouts you build send straight back to your head unit. Beneath all of it is the decision everything else follows from: the athlete is the only valid reference point. Your thresholds are measured from your own efforts. Your zones hang off those thresholds. Your limiter is where your own curve falls short of your own model. If a number cannot be traced back to something you actually did, OSO does not show it.

Refusing population tables does not mean inventing our own version of physiology. The models under OSO are the published, peer-reviewed backbone of endurance science: the Banister impulse-response model behind fitness and form, the Critical Power framework behind your engine profile, the Minetti cost curve behind grade-adjusted pace. Every one is named and cited on our Training Science page, because a number you cannot interrogate is a number you should not trust.

The other half of the standard is restraint. Every insight in OSO carries the evidence it was computed from, every detector is built to stay silent for an athlete who only almost triggers it, and thin data produces hedged conclusions or none at all. Plenty of platforms will always tell you something. We would rather be the one you believe when you get home from the ride.

The dashboard you come back to should feel like it was built this decade, and built for you. OSO is in private beta, free while it runs, and under heavy active development: Strava, Garmin, Wahoo, Polar and Hammerhead connect today, structured workouts send to your head unit, and running dynamics, durability analysis and recovery baselines all shipped recently. The pace of change is fast, beta athletes shape the roadmap directly, and the fastest way to influence what gets built is to train with it and tell us where it falls short.

If that sounds like your kind of tool, the invite system is how you get in: join the waitlist from the homepage, or use an invite link if a beta athlete has shared one with you.