CardioEngine vs Zone2 Autopilot
Price, ratings, monetisation and update history for both apps, side by side โ with what reviewers say about each.
CardioEngine
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CardioEngine builds your heart rate zones from your aerobic threshold, not your age. Most cardio apps tell you to "aim for 60โ70% of max HR." That number is derived from your age and tells you almost nothing. Your aerobic threshold is the actual boundary between fat-burning aerobic work and glycolytic effort. CardioEngine finds yours and builds five zones around it. ZONE-BASED LIVE COACHING Once your workout starts, CardioEngine watches your heart rate and tells you when you drift out of your target zone. Too high? Ease off. Too low? Push a little. No guessing, no manual math. WORKS WITH YOUR HR MONITOR Connect your Polar, Garmin, Wahoo, or any Bluetooth chest strap. Pair your Apple Watch. CardioEngine reads from whichever source is most reliable โ if your watch drops out mid-run, it switches to your chest strap without missing a beat. YOUR WEEKLY TRAINING PICTURE Set a weekly cardio volume target. CardioEngine totals your zone 2 minutes across every session and shows how far you are from your goal. The dashboard marks each training day so you know exactly where you stand heading into the weekend. ZONE PROFILE BUILT FOR YOU Your five zones are calibrated from your estimated aerobic and lactate thresholds, not a population average. Your zones update as your fitness changes. A confidence score tells you how solid the estimate is โ low score just means you need more workout data. FASTED CARDIO Fasting raises your heart rate at any given effort level. CardioEngine accounts for this by shifting your zone ceilings down a few beats, so your targets stay meaningful when you're training before breakfast. WHY ZONE 2 Zone 2 is where mitochondrial adaptations happen. Maffetone and Attia have both written on why most people train too hard and get too little from it. CardioEngine keeps you in that range. โข Live zone coaching during workouts โข Bluetooth HR monitor + Apple Watch support with automatic failover โข Personalized zone profile from your aerobic threshold โข Weekly volume tracking with session history โข Fasted cardio mode โข Treadmill, stationary bike, recumbent bike, rower, stair stepper, and elliptical โข watchOS companion app
Zone2 Autopilot
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The usual way to ride Zone 2 is a fixed power target, but fixed watts can't account for how your heart rate responds or drifts as you warm up and tire. Zone2 steers by heart rate instead. It adjusts your smart trainer's power in real time to help keep you inside the Zone 2 band you set - no FTP test, no workout to pick, no numbers to chase. Press start and pedal. As an early tester put it: "That was my best Zone 2 workout ever. No joke. I get distracted and usually end up way too high." What you get: - One-tap start after setup - Automatic trainer adjustments to help hold your saved heart-rate band - Live cadence with a spin-up nudge when you start to grind - Time inside your saved Zone 2 band to see how much of each ride stayed in range - Auto-pause and resume when you stop and start - Works with FTMS smart trainers that support Bluetooth ERG target-power control, plus Bluetooth heart-rate straps (developed and validated on a Wahoo KICKR and Polar H10) - Apple Health sync - No trainer yet? See a demo ride and stats with no hardware Free. No ads, no subscriptions, no tracking. Your data stays on your device unless you choose to export it or connect Apple Health.
Screenshots
Verdict
The clearest difference is in-app purchases: Zone2 Autopilot at none against CardioEngine's 1. Zone2 Autopilot also leads on iOS requirement (17.0 vs 26.0). On price, update cadence, ads and device support there is nothing between them.
Scored on Price ยท Rating ยท Positive reviews ยท Number of ratings ยท Update frequency ยท Ads ยท In-app purchases ยท Monetization ยท Best chart rank ยท Devices ยท Requires iOS
Both are free to download. CardioEngine sells 1 one-off in-app purchase. Zone2 Autopilot asks for nothing beyond the download.
CardioEngine ships an update every 9 days, Zone2 Autopilot every 8 days. The most recent releases landed on October 19, 2026 and October 10, 2026 respectively.
| Parameter | CardioEngine | Zone2 Autopilot |
|---|---|---|
| Price | Free | Free |
| Update frequency | Every 9 days | Every 8 days โ better |
| Ads | No | No |
| In-app purchases | Yes | No โ better |
| Devices | iPhone, Apple Watch | iPhone, iPad |
| Requires iOS | 26.0 | 17.0 โ better |
| Further details โ not scored | ||
| Size | 9 MB | 10 MB |
| Age rating | 4+ | 4+ |
| Developer | Feeling Mindful Labs LLC | Brad Richardson |
In-app purchases
CardioEngine
- CardioEngine Full Access$29.99
Zone2 Autopilot
No in-app purchases
Questions
Is CardioEngine free?
Is Zone2 Autopilot free?
Do CardioEngine or Zone2 Autopilot have ads?
Which is updated more often, CardioEngine or Zone2 Autopilot?
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