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VO₂max.One
Quick Intro

Quick Intro · 30 seconds

Captions & transcript
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30 seconds: what VO₂max is, why it predicts your healthspan, and how we close the loop.

Works with Apple Watch & Fitbit

Music at your heart rate, beat for beat.

Your watch reads your heartbeats per minute. VO₂max.One generates the workout track at that same beats per minute — faster as you push, slower as you recover — so the music does the pacing instead of you.

  1. Your device
  2. Your goal
  3. The match
1. What are you wearing?
2. What is today's workout?

3. Pick a device and a workout to see the heart rate we aim for and the tempo the music plays at.

Hear a generated sessionWhy it matters

AI-GENERATED AUDIOComposed by a generative model from your physiological data. Not a medical device — fitness guidance only.

FTC 16 CFR §255 · EU AI Act Art. 50
AeroGlyphics — VO₂max music videoA short clip prescribed from a real heart-rate zoneSource

The problem we are solving

Music was never built to keep up with your effort.

You train with a watch that measures everything and a soundtrack that measures nothing. So the workout and the music pull in different directions.

  • Your playlist ignores your body

    A fixed playlist plays the same 128 BPM whether you are warming up, redlining or barely recovering.

  • You drift out of the zone

    Without a cue the moment your heart rate slips, easy days go too hard and hard intervals go too soft.

  • Your watch data just sits there

    Apple Health and Fitbit already know your VO₂max, pace and zones — nothing uses them while you move.

Our answer

VO₂max.One turns your live heart rate into a prescription, not a playlist — music that paces the workout you actually set out to do.

  • Tempo and energy follow your live heart rate, beat by beat
  • Six phases prescribed from your VO₂max, goal and zone
  • Every session logged, exportable and shareable
Fix my workout music See how it adapts

Don't choose a playlist

Choose how you want to feel.

One selection sets the whole session — BPM, energy, groove, tension and recovery. Tap a mood to open the generator already tuned to that zone.

The demoGenerate a session nowSix phases, target heart-rate bands and the music settings behind each block — no watch required.See demo answersThe scienceVO₂max, zones, tempoTanaka HR-max, heart-rate reserve zones, and why tempo paces effort better than a playlist.Read the scienceMake this easyMeasure. Generate. Move. Adapt.The closed loop from watch to audio and back — plus permissions, storage and what we never write.Follow the loop

Before you move

Set the goal. The music follows.

Duration, intervals, calories, distance — tell us the shape of the session and the soundtrack is built around it.

Today's focus

Your soundtrack

30 min · Intervals

128–168 BPM · 6 music blocks · zone 4

  • Warm-up5 min

    Slow build, wide open sound

  • Intervals21 min

    6 rounds — beat drops on each work bout

  • Cool-down5 min

    Tempo falls with your heart rate

Calorie goal
320 kcal
Distance goal
5 km
Generate this session

Free to try — no watch needed for the demo.

What VO₂max is, and why it predicts so much2 min read · animated scaleShow

Start here · 10 seconds

The most important number your doctor has never measured.

Joel Selanikio, MD — “The Most Important Number Your Doctor Has Never Measured” (opens in a new tab)

VO₂max is the most oxygen your body can take in, move and burn in one minute, measured in millilitres per kilogram per minute. It is the single best physical measure of how well your heart, lungs, blood and muscle work together — and the strongest predictor of how long, and how well, you will live.

The urgency: it falls every year you leave it alone, almost nobody has it tested, and the only thing that raises it is training at the right intensity — the exact thing most workouts get wrong. Your watch already estimates it. We are the first system to prescribe your music from it, so every minute you move is spent in the zone that actually moves the number.

  • #1

    Strongest predictor

    VO₂max predicts all-cause mortality more strongly than smoking, blood pressure or cholesterol.

  • −10%

    Per decade after 30

    Aerobic capacity falls about a tenth every decade unless you train the system that carries oxygen.

  • 2×

    Low vs high fitness

    Moving out of the bottom fitness quintile roughly halves the risk that comes with being unfit.

Your aerobic capacity

Aerobic capacity scale in millilitres per kilogram per minute: at risk below 30, average 30 to 40, fit 40 to 50, elite 50 and above. A typical trained forty-year-old sits near 48. Every session on VO₂max.One is prescribed to push this bar — the music changes so the number does.
Read the thesis (opens in a new tab)
How a session works, step by stepDevices · six phasesShow

Bring the watch you already wear

  • Apple WatchApple HealthConnect now
  • FitbitFitbit Web APIConnect now
  • GarminGarmin ConnectComing soon
  • WhoopWhoop APIComing soon

Apple Watch metrics arrive through Apple Health; Fitbit through the Fitbit Web API. No device? Enter your numbers by hand and we estimate the rest.

Make this easy

Three steps. Then just move.

  1. 01

    Wear your watch

    Heart rate, VO₂max and recovery come straight from Apple Health or Fitbit. Nothing to type in.

  2. 02

    Set your goal

    Duration, intervals, calories or distance. Change your mind mid-session and the plan reshapes.

  3. 03

    Press play

    Six phases of music track your effort — lifting you into the work and easing you out of it.

How it stays honest — AI disclosure, privacy and data handlingComplianceShow

AI-GENERATED AUDIOComposed by a generative model from your physiological data. Not a medical device — fitness guidance only.

FTC 16 CFR §255 · EU AI Act Art. 50

Clinically minded

Zones follow the Tanaka HR-max formula and heart-rate reserve — the same maths your coach uses.

Your data stays yours

Sessions live on your device. Share a result with a link you can revoke at any time.

Cleared for release

Every track is labelled AI-generated, watermarked and registered so artists get credited.

Reference — devices, goals and what gets generatedTablesShow

Start here

Pick the fastest way in.

Six ways to get value in the next five minutes. Every route works on a phone.

Generate my first sessionConnect my watch first

Your next workout has a soundtrack.

Try a session in the browser — then bring your watch.

Start a sessionRead the FAQI'm a partner