Zone 2 AI: Vo2 Max & Endurance

Name: Zone 2 AI: Vo2 Max & Endurance
Rating: 4.5 (30 reviews)
Author: Unbounded Technologies LLC

Fat Burn Zones Coach

Free · In‑App Purchases

30 Ratings
Ages

9+
Years
Category

Health & Fitness
Developer

Unbounded Technologies LLC
Language

EN
English
Size

65.9
MB

Build the Engine. Raise the Ceiling. Zone2AI is the complete longevity protocol. We combine steady-state Zone 2 training (to build mitochondrial efficiency) with the science-backed Norwegian 4x4 Sprint Protocol (to maximize VO2 Max). Whether you follow Peter Attia, Andrew Huberman, or Inigo San-Millán, you know that "exercise is the most potent longevity drug." Zone2AI is the only app that prescribes the exact dosage, validates your effort, and projects your future health. INTRODUCING ZONE2AI 2.0 - The Sprint Protocol (Norwegian 4x4): Zone 2 builds the foundation; Sprints build the skyscraper. Unlock "Sprint Credits" by completing your Zone 2 base, then redeem them for guided High-Intensity Interval Training (HIIT) designed to spike your VO2 Max. - Zone2AI Power Score: Are you becoming more metabolically efficient? We calculate your unique Power Score (Watts/kg) to measure exactly how much power your body can generate while remaining in a fat-burning state. - The Path (Future You): Don't just track today; visualize tomorrow. See how your current training trajectory impacts your predicted biological age and VO₂ Max over the next decade. - Incline Calibration: Training on a treadmill? Our new calibration tool helps you find the perfect incline to hit your metabolic peak without running. From "Restoration" to "Performance," choose the path that fits your biological reality. We build a custom weekly prescription based on your age, gender, and resting heart rate. CORE FEATURES - True Zone 2 Validation: We don't just log minutes. We filter your Apple Health data to find *actual* Zone 2 sessions: steady-state cardio in your personal biosignal range, sustained for as long as your personalized plan calls for. No false positives. - Apple Watch Haptics: Stay in the zone without looking at your wrist. Get subtle, real-time haptic feedback when you drift out of your target range during Zone 2 or Sprint sessions. - The Weekly Dose: Track your progress toward the ideal scientific benchmark of 180–240 minutes/week. - Total Privacy: No ads. No selling data. We use on-device logic and anonymized processing to generate your insights. Your biological data belongs to you. - Universal Sync: Works with your Apple Watch, Polar, Garmin, Strava, WHOOP: anything that writes workouts to Apple Health. Zone2AI is built for anyone seeking to build a real zone 2 habit. From beginners to high-performance individuals: biohackers, endurance athletes, and anyone optimizing for mitochondrial health and longevity. This is not a general fitness tracker. This is a precision tool for a longer life. Train in Zone 2. Sprint for VO2 Max. Defy your age. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

Ratings & Reviews

4.5

out of 5

30 Ratings

Not Attia’s Zone 2
08/29/2025

cruiseandresort
Conceptually, I like this app. But it’s suggesting that I work out above my lab-measured lactate threshold and there’s no way for me to adjust so the metrics. My lactic threshold is 118 bpm but the app recommends 113 to 125 BPM to reap the benefits of Attia’s Zone 2 training. Five stars if I could set my own lactate threshold in the app.

Developer Response
Thanks for the thoughtful review, and for sharing your lab-measured lactate threshold data (the holy grail of zone 2 data). That level of precision shows you're serious about getting Z2 right, and we respect that.You're absolutely correct: while the app currently calculates your range using age, max HR, and 30-day resting HR average, it doesn’t yet allow users to manually input a lab-tested LT1 (lactate threshold). That’s a feature we agree is important for more advanced users, and it’s on our roadmap.We recommend trying our Apple Watch companion app, which makes it easier to stay aware of your live Zone 2 minutes during a workout. And we’ll keep you posted as we build out the ability to fully personalize ranges, including by setting your own lactate threshold.Thanks for using Zone2AI and helping us improve. this kind of feedback pushes us forward.best, Rod & Zone2Ai team
Not Attia’s Zone 2
08/29/2025

cruiseandresort

Conceptually, I like this app. But it’s suggesting that I work out above my lab-measured lactate threshold and there’s no way for me to adjust so the metrics. My lactic threshold is 118 bpm but the app recommends 113 to 125 BPM to reap the benefits of Attia’s Zone 2 training. Five stars if I could set my own lactate threshold in the app.
Developer Response 09/15/2025
Thanks for the thoughtful review, and for sharing your lab-measured lactate threshold data (the holy grail of zone 2 data). That level of precision shows you're serious about getting Z2 right, and we respect that.You're absolutely correct: while the app currently calculates your range using age, max HR, and 30-day resting HR average, it doesn’t yet allow users to manually input a lab-tested LT1 (lactate threshold). That’s a feature we agree is important for more advanced users, and it’s on our roadmap.We recommend trying our Apple Watch companion app, which makes it easier to stay aware of your live Zone 2 minutes during a workout. And we’ll keep you posted as we build out the ability to fully personalize ranges, including by setting your own lactate threshold.Thanks for using Zone2AI and helping us improve. this kind of feedback pushes us forward.best, Rod & Zone2Ai team
5 Stars - Game Changer for My Fitness Journey!
04/16/2025

cesarfierro1
Zone 2 AI has completely transformed the way I train. I’ve always struggled with staying in the right heart rate zone during my cardio sessions, but this app makes it so easy and effective. The AI-driven insights are incredibly accurate and personalized — it feels like having a virtual coach right in my pocket.What I love the most is how intuitive the interface is. It tracks my progress, adjusts to my fitness level, and keeps me motivated with real-time feedback. I’ve noticed major improvements in my endurance, fat-burning efficiency, and overall performance.If you’re serious about optimizing your training and want an app that’s both smart and supportive, Zone 2 AI is a must-have. This isn’t just another fitness app — it’s a total game changer!
5 Stars - Game Changer for My Fitness Journey!
04/16/2025

cesarfierro1

Zone 2 AI has completely transformed the way I train. I’ve always struggled with staying in the right heart rate zone during my cardio sessions, but this app makes it so easy and effective. The AI-driven insights are incredibly accurate and personalized — it feels like having a virtual coach right in my pocket.What I love the most is how intuitive the interface is. It tracks my progress, adjusts to my fitness level, and keeps me motivated with real-time feedback. I’ve noticed major improvements in my endurance, fat-burning efficiency, and overall performance.If you’re serious about optimizing your training and want an app that’s both smart and supportive, Zone 2 AI is a must-have. This isn’t just another fitness app — it’s a total game changer!
Game-changer for my Zone2 training!
03/16/2025

Stanford Palmtrees in Sarasota
I’ve been trying to build a solid Zone 2 habit for years, but tracking it manually was always frustrating. Since using Zone2 AI, I’ve logged over 240 minutes of real Zone 2 per week for the last 5 weeks—and the results speak for themselves! 🚀🔥 My VO2 Max has jumped from low to above average—all because I finally have a simple, automated way to track my Zone 2 time. The app syncs effortlessly with Apple Health, and once you set it up, you’re good to go. No extra steps, no manual inputs—just train and let the app handle the rest.If you’re serious about improving endurance and cardiovascular health, this is the must-have app. 💪💙
Game-changer for my Zone2 training!
03/16/2025

Stanford Palmtrees in Sarasota

I’ve been trying to build a solid Zone 2 habit for years, but tracking it manually was always frustrating. Since using Zone2 AI, I’ve logged over 240 minutes of real Zone 2 per week for the last 5 weeks—and the results speak for themselves! 🚀🔥 My VO2 Max has jumped from low to above average—all because I finally have a simple, automated way to track my Zone 2 time. The app syncs effortlessly with Apple Health, and once you set it up, you’re good to go. No extra steps, no manual inputs—just train and let the app handle the rest.If you’re serious about improving endurance and cardiovascular health, this is the must-have app. 💪💙
Too literal
09/09/2025

mad dog.
All this app really does is screen your workouts for any that meet its very strict definition for zone 2 and then provide you with some AI babble to go along with it. My main complaint is that if you do a 50-55 minute steady state workout with an average HR in the dead center of your zone 2 range, it likely won’t count as it usually takes a few minutes at the beginning to ramp up to your target range and if there is any noise in your HR data (common with wrist mounted monitors like Apple Watch, garmin, etc) you won’t end up with the minimum 45 minutes in range that it requires. Also, if there is a way to customize the Zone 2 HR range, I couldn’t find it.

Developer Response
Thanks for the feedback. We hear you.Zone2AI uses a rigorous definition of Zone 2 because the research (including from Dr. Peter Attia) shows that you need at least 45 continuous minutes in your true Zone 2 to unlock the full mitochondrial and metabolic benefits. Were not strict for the sake of it; we do it to helping you hit the threshold that matters for long-term health and performance.We understand your frustration. Especially when ramp-up time makes it hard to get credit for the work you’re doing. We're actively working on ways to make the experience more friendly while staying true to the science.We invite you to try our Zone2AI Apple Watch companion app, which shows you in real time how many minutes you've logged in valid Zone 2. That way, there's no guesswork, and you’ll know exactly when you’ve hit that 45-minute mark.Our next release will include the ability to customize the HR range, and guidance on incorporating Zone 5 / VO2 max sessions, which help you unlock the full benefits of the aerobic training "pyramid"Thanks again for your support and for being part of this early journey. We're building Zone2AI to be the simplest, smartest way to train for health and longevity. Your feedback helps us get there.
Too literal
09/09/2025

mad dog.

All this app really does is screen your workouts for any that meet its very strict definition for zone 2 and then provide you with some AI babble to go along with it. My main complaint is that if you do a 50-55 minute steady state workout with an average HR in the dead center of your zone 2 range, it likely won’t count as it usually takes a few minutes at the beginning to ramp up to your target range and if there is any noise in your HR data (common with wrist mounted monitors like Apple Watch, garmin, etc) you won’t end up with the minimum 45 minutes in range that it requires. Also, if there is a way to customize the Zone 2 HR range, I couldn’t find it.
Developer Response 09/15/2025
Thanks for the feedback. We hear you.Zone2AI uses a rigorous definition of Zone 2 because the research (including from Dr. Peter Attia) shows that you need at least 45 continuous minutes in your true Zone 2 to unlock the full mitochondrial and metabolic benefits. Were not strict for the sake of it; we do it to helping you hit the threshold that matters for long-term health and performance.We understand your frustration. Especially when ramp-up time makes it hard to get credit for the work you’re doing. We're actively working on ways to make the experience more friendly while staying true to the science.We invite you to try our Zone2AI Apple Watch companion app, which shows you in real time how many minutes you've logged in valid Zone 2. That way, there's no guesswork, and you’ll know exactly when you’ve hit that 45-minute mark.Our next release will include the ability to customize the HR range, and guidance on incorporating Zone 5 / VO2 max sessions, which help you unlock the full benefits of the aerobic training "pyramid"Thanks again for your support and for being part of this early journey. We're building Zone2AI to be the simplest, smartest way to train for health and longevity. Your feedback helps us get there.

Bug fixes and performance improvements.

Version 2.1.9

Feb 24

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Fat Burn Zones Coach

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Version 2.1.9

App Privacy

Data Used to Track You

Data Not Linked to You

Accessibility

Information

Supports

Family Sharing

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