Explainer
VO₂max in 30 seconds
The number your doctor has never measured, and what happens when you turn it into a soundtrack. Subtitles are burned in, captions are selectable, and the full transcript below jumps the video to any moment.
Open captions + WebVTT Full transcript30 seconds · female narration + open captions
MP4No decoder errors
Full transcript
Every caption in the film, in order, with its timecode. Select a timecode to jump the video to that moment, or copy its link to share that exact moment. Nothing in the animation carries meaning that is not written here.
The number nobody measures
- The most important number your doctor has never measured.
What VO₂max is
- VO₂max is the most oxygen your body can use.
Why it matters
- Fitness is a vital sign.
- It predicts how long you live.
Our innovation: the closed loop
- So we turned it into a soundtrack.
- AI music locks its tempo to your heart rate.
Measure it, train it, hear it
- VO₂max.One — your heartbeat writes the soundtrack.
7 caption cues · transcript, burned-in subtitles and the WebVTT track are generated from one source, so they cannot drift apart.
Questions about the film
- What is VO₂max?
- VO₂max is the maximum amount of oxygen your body can take in and use during hard exercise, measured in millilitres of oxygen per kilogram of body weight per minute. It is one number that summarises how well your heart, lungs, blood and muscles work together.
- Why does VO₂max matter more than most lab numbers?
- Across large long-term studies, VO₂max is the single strongest predictor of all-cause mortality — a stronger signal than smoking, blood pressure or cholesterol. Fitness behaves like a vital sign, yet almost no clinic measures it because a traditional test needs a mask, a treadmill and a lab.
- How does the closed loop between heart rate and music work?
- Your watch streams heart rate beat by beat. The AI music engine locks its tempo to that heart rate and to the phase of your prescribed session, so the track pushes your effort; your effort then changes your heart rate, which rewrites the music. Music and physiology continuously correct each other.
- Is the explainer video accessible without sound?
- Yes. A female voice narrates the film, and every point is also written on screen as burned-in subtitles, with a selectable WebVTT caption track and the full timestamped transcript on this page, which you can download as a text file or a PDF. Nothing is lost with the sound off.
- Yes. Every timecode and chapter in the transcript has a copyable link that carries a start time, so opening it seeks the player straight to that moment.
Hear the loop for yourself
Enter a VO₂max and a goal, and the engine returns the six-phase prescription the film describes.