Zone2 Engine
Best experienceApple Watch
A Watch app with haptic coaching on your wrist, synced with your iPhone.
NEW On-device AI plans your week
Build your engine.
An AI coach that plans your week around the days you can train, then live heart rate coaching keeps you in Zone 2. Easy minutes, real results.
Zone 2, explained
Easy enough to talk.
Easy enough to talk.
Hard enough to change you.
Your heart rate falls into five zones. Zone 2 is the steady one, and it's where most of your training should live. Tap a zone to see how it feels.
Z2
Zone 2 · Endurance
Steady and comfortable. You can talk in full sentences. This is where your heart and muscles get better at burning fat for fuel, and you recover by tomorrow.
Of max HR60–70%Talk testFull sentences
Apple Intelligence · on device
A coach that plans
This week150 min goal
A coach that plans
your week.
Pick the days you can train, how long you have and what you like doing. Your coach turns your weekly goal into sessions, then rebuilds the plan every time a workout lands.
MonWalk · 40 minZone 2 the whole wayDone
WedIndoor ride · 35 minKeep it steady, 129–141 bpmToday
FriWalk · 20 minShort and easyFri
SatIndoor ride · 55 minYour long sessionSat
- Try it free. Your first week's plan is on us. Keeping it adapting week after week is part of Pro.
- Private by design. Apple's on-device model writes your plan. Nothing is sent to a server.
- Rules own the numbers. Minutes and targets come from proven training rules. The AI explains them in plain words.
Live coaching
Know what to do.
Know what to do.
Right now.
The screen glows in your zone colour and says it plainly. A heart that beats with yours, a live chart against your target band, calm haptics on your wrist and voice cues in your AirPods.
Pick it up
Below your band. A gentle nudge, never a siren.
In zone
Right where you should be. Keep it steady and enjoy it.
Ease off
Drifting into Zone 3. Slow down a touch, you'll get more from it.
Apple Watch
Leave the phone.
Leave the phone.
Keep the coach.
The Watch app reads your heart rate from your wrist, glows in your zone colour and taps you when to ease off or pick it up. Your weekly ring and today's coach line come along from your iPhone.
Your week
Fill your ring.
Fill your ring.
From any app.
Set a weekly goal, like 150 minutes. Every workout with heart rate in Apple Health counts: walks, runs, rides and rows, recorded here or anywhere else.
0Min left
0Days left
0%Of goal
- Widgets and Live Activity keep your week on the Home Screen, Lock Screen and Dynamic Island.
- Your real Zone 2. Formulas can be 10 beats off. Zone2 Engine reads how your heart rate drifts on long sessions and suggests when to move your ceiling.
0of 150 min
Works with
Use what you wear.
Your sensor is pinned and reconnects on its own. If the app is closed mid-workout, the session is recovered.
Best experience
Garmin & others
Turn on heart rate broadcast and your watch pairs like a strap.
Most accurateChest straps
Any standard Bluetooth heart rate strap: Polar, Wahoo, Garmin, COROS and more.
iPhone only
No sensor today? Your weekly ring still fills from workouts in Apple Health.
Privacy
Your heart stays
Your heart stays
on your phone.
On-device AI
Plans and coaching are written by Apple's model on your iPhone. No cloud AI, no API calls.
No account
No sign-up, no email, no password. Open the app and train.
Health data never leaves
Heart rate and workouts are never sent to us or used for ads. Read the policy.
Inside the app
Every number, explained.
Short illustrated explainers sit behind every metric, so you always know why.
Pricing
Free to train.
Free to train.
Pro when you want more.
Free
$0
Forever. No account.
- Live coaching on iPhone and Apple Watch, with haptics and voice
- Weekly ring from every workout
- Daily coach: what to do today
- Widgets and Live Activity
- Your first AI weekly plan, on us
Free trial on yearly
Pro
$29.99 / year
or $3.99 a month, or $59.99 once
- Everything in Free
- AI weekly plan, rebuilt every week and after every workout
- Intervals, including the Norwegian 4×4
- Long-term trends and the 80/20 split
- Your personal Zone 2 check
- Strava upload
Prices in USD; local prices are shown in the App Store before you pay. Cancel any time in iOS Settings.
Questions
Do I need an Apple Watch?
No. Any Bluetooth chest strap works with just your iPhone, and so do Garmin and other watches that broadcast heart rate. Without a sensor, your ring still fills from workouts other apps save to Apple Health.
Is the AI plan free?
Your first week's plan is free. After that, the AI weekly plan is part of Pro, with a free trial on the yearly plan. Live coaching, your weekly ring, the daily coach, widgets and the Watch app stay free forever.
Does the AI need the internet or an account?
No. On iPhones with Apple Intelligence, the plan and coaching are written by Apple's on-device model. On other iPhones the same plan is built by the app's training rules, with simpler wording. Either way, nothing is sent to a server.
How are my zones set?
From your age and resting heart rate in Apple Health. You can switch between five methods (% of max, heart rate reserve, threshold, MAF 180 or manual), and the app suggests adjustments based on how your heart rate drifts on long, easy sessions.
Do workouts from other apps count?
Yes. Any workout with heart rate in Apple Health counts toward your week, from Apple Fitness, Strava, Garmin Connect, Peloton and others.
Is this medical advice?
No. Zone2 Engine is a training tool, not a medical device. Talk to your doctor before starting a new exercise program.
Android?
Coming soon. Zone2 Engine launches first on iPhone and Apple Watch, with Android on the way. Want a heads-up when it's ready? Email us and we'll let you know.
Coming soon to the App Store
Slow down.
Slow down.
Build up.
Zone2 Engine is almost ready for iPhone and Apple Watch. Questions or want early access? Drop us a line.