The best VO₂max apps.
“VO₂max app” means two different things: apps that estimate your VO₂max, and apps that trainit. The best one depends on which you're after — here's an honest breakdown by use case.
Transparency: we make Stellar Intervals. So we've grouped apps by what each is genuinely best at rather than ranking them 1–10, and we've tried to be straight about where another tool is the better pick.
At a glance
| App | Best for | HR-gated intervals | VO₂max estimate | Platforms |
|---|---|---|---|---|
| Stellar Intervals | The Norwegian 4×4 / threshold-gated intervals | Yes | Tracks HR recovery | iOS, Android |
| Garmin (Connect + watch) | All-round training + a VO₂max estimate | No | Yes | iOS, Android, watch |
| Apple Watch / Fitness | A passive VO₂max estimate for Apple users | No | Yes | iOS, watch |
| Zwift / TrainerRoad | Structured indoor cycling workouts | Targets, not HR-gated | No | iOS, Android, desktop |
| Generic interval timers | Simple HIIT timing | No | No | iOS, Android |
Best for training VO₂max (the 4×4)
If your goal is to raise your VO₂max, you need to run the Norwegian 4×4correctly — and that means a timer that counts your interval only while you're above 85% of max heart rate. Stellar Intervalsis built for exactly this: it's threshold-gated, reads live heart rate at 1 Hz from a strap, a Garmin sensor, or AirPods Pro 3, and tracks your heart-rate recoveryso you can see fitness improving. A generic interval timer can't do this — it counts your ramp-up as work.
Best for estimating your VO₂max
To just know your number, a Garmin or Apple Watchis the easiest path: both estimate VO₂max passively from your runs and walks. They're estimates rather than lab measurements, but they're great for watching the long-term trend — ideally the trend you're moving with 4×4 sessions.
Best for structured indoor work
For guided indoor cycling, Zwift and TrainerRoadoffer structured workouts that include VO₂max intervals built around power targets. They're excellent training platforms; they just aren't heart-rate-gated, so the dose is set by power rather than confirmed by heart rate.
How to choose
- Want to raise VO₂max with the 4×4? A heart-rate-gated interval app — Stellar Intervals.
- Just want your number? A Garmin or Apple Watch.
- Train indoors on the bike with a plan? Zwift or TrainerRoad.
- Most people doing this seriously use two: a watch to estimate, and an interval app to train.
Frequently asked questions
- What is the best app for VO₂max?
It depends on what you want. To train VO₂max with the Norwegian 4×4, a heart-rate-gated interval app like Stellar Intervals is the best fit. To passively estimate your VO₂max number, a Garmin or Apple Watch is the easiest route. To follow structured indoor cycling plans, Zwift or TrainerRoad. They solve different problems.
- Is there an app that just gives me my VO₂max?
Yes — Garmin watches and Apple Watch both estimate VO₂max from your heart rate relative to pace or power during runs and walks, no extra effort required. They're estimates, not lab measurements, but they're useful for tracking the trend.
- What's the difference between estimating and training VO₂max?
Estimating tells you roughly where your number is today; training is the work that moves it. A watch estimates; an interval app like Stellar Intervals runs the protocol (the Norwegian 4×4) that actually raises it. Most serious users use one of each.
- Do I need a paid app to train VO₂max?
No. The protocol is free — you just need a way to time heart-rate intervals accurately and a heart-rate monitor. The value of a dedicated app is doing the protocol correctly (gating the timer on heart rate) and tracking progress so you know it's working.
Train at VO₂max.
If the goal is to raise VO₂max, you need the 4×4 done right — Stellar Intervals counts only the minutes above 85% of max.