About spira
spira is a physiological training system. Two modules: VO₂max interval training and breathwork protocols. Audio-guided, heart rate aware, minimal by design.
Why it exists
Most training apps track what you did. Very few tell you what to do — and almost none are built on the physiology of how aerobic capacity actually develops. spira closes that gap: research-informed protocols, structured six-week progressions, and a voice that guides every session so you never train looking at a screen.
What spira is not
Not a fitness tracker. Not a meditation app. Not a social platform. No feeds, no streaks, no leaderboards, no badges. spira rewards completed structure and recovered capacity — not suffering.
How it's built
Every protocol is research-informed, built from published interval and breathing research — Helgerud, Billat, Seiler, and the work that followed. The science notes inside the app explain why each session is structured the way it is. Built by an athlete who trains with it, every week, before anything ships.