VO2 Max vs Train.Red APP
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
VO2 Max
Track your body's oxygen absorption at peak effort with detailed insights and performance estimates for running and cycling. Visualize trends, compare personal bests, and understand your cardio fitness level with a redesigned dashboard and Apple Watch integration.
- VO2 max estimation for running and cycling
- Performance estimates (W/kg, FTP)
- Redesigned dashboard with trends and personal bests
- Interactive charts with customizable date ranges
- Apple Watch complications and iPhone widgets
- Cardio fitness level comparison by age and sex
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VO₂ Max shows how much oxygen your body can absorb at peak effort. The redesigned dashboard puts the latest measurement, rolling averages, and your personal best in one view so you immediately see how training affects cardio fitness. ESTIMATES FOR RUN & BIKE - New tab turns VO₂ max + weight + power into W/kg and FTP estimates for running and cycling. - Compare modeled race times and power against your actual HealthKit FTP/power. NEW DASHBOARD - Trend cards highlight the 7-day average, any selected range, and your best value with percentage deltas. - The interactive chart responds to 1W, 2W, 1M, 3M, 1Y, or All filters and animates every new HealthKit reading. - Entry tiles list the test type, source, and timestamp so you can compare prediction and max-exercise tests. INSIGHTS & GUIDANCE - The info sheet matches your value with the correct age and sex bracket to explain whether it is poor, good, or superior. - Manual refresh, HealthKit warnings, and empty states keep permissions and sync issues obvious. - Trial countdown and subscription access stay a tap away. APPLE WATCH + WIDGETS - All complication families are supported, so your latest VO₂ max is available on every watch face. - iPhone Home Screen and Lock Screen widgets follow the dashboard range you selected. - The Widget Showcase walks you through pinning widgets or complications and previewing layouts. HOW VO₂ MAX IS CAPTURED 1. Wear Apple Watch for at least 24 hours, then record several Outdoor Walk, Outdoor Run, or Hiking workouts with heart rate and GPS. 2. Apple may need several qualifying workouts and passive measurements before the first VO₂ max estimate appears. 3. Give this app read access to Cardio Fitness (VO₂ Max) in Apple Health so the dashboard, widgets, and complications can display the data. Requires Apple Watch Series 3 or later. VO₂ Max makes it easy to see if your cardio fitness plan is working today, over the last weeks, and all time. Terms and conditions: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
Train.Red APP
This app monitors muscle oxygen saturation to provide real-time physiological insights for athletes and coaches. It helps optimize performance, track recovery, and analyze training data with actionable metrics.
- Muscle oxygen saturation monitoring
- Real-time physiological insights
- Performance and recovery tracking
- Workout analysis and data export
- Team/organization structure
- Live data overlay
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About this app The official app for the Train.Red muscle oxygen sensors, the new metric for performance. To move, your muscles need energy. The most efficient way to get this energy requires oxygen. We measure the oxygen saturation in your muscles to help you improve. Not every athlete has a team of scientists helping them with their physiological data, we measure data from your muscle and translate this into useable insights, in real-time. - Monitor your physiological power and perform easy exercise tests as an endurance athlete. - Know when your muscle is fully recovered and ready for the next set when doing strength. What’s more? - Cloud functionality to allow workout analysis at home, even when you perform in the gym. - A Team/organisation structure that allows multiple athletes to use the sensors. - Actionable insights after your training or scientific analysis with access to raw data. - Live view with data overlay to match measured fatigue with movement patterns. - Muscle States, Protocols, Dashboard, Training Menu, Muscle Stress Score, and much more. How to start with Train.Red: Create a user profile and connect your sensor. No sensors yet? The Train.Red app requires the Train.Red sensors for full functionality (https://train.red/). Connected your FYER or PLUS? Nice, you are ready to BE AHEAD. What does Train.Red do for me: Whether you’re an athlete, coach, scientist, physio, or anyone involved in sport, Train.Red has something to offer you. Simply because your muscles play a key role in human movement. We track your muscle oxygenation, more specifically, the hemoglobin concentration changes. The Train.Red sensors measure: - SmO2, Muscle Oxygen Saturation (%) - O2Hb, Oxyhemoglobin (mM) - Hhb, Deoxyhemoglobin (mM) - Thb, Total hemoglobin (mM) - HbDiff, the Hemoglobin Difference (mM) If this sounds like Abracadabra, no worries. We display the oxygen saturation in your muscle live and use the other metrics to provide you with actionable insights in real-time. Our AI and advanced analysis options translate this data into 5 different muscle states showing you if your muscle is recovering, or approaching its limits. If this physiological data sounds familiar, perfect. We allow exporting your data to .csv or .fit files for an in-depth analysis of all your data. Every single training session is stored in our cloud and can be analyzed or exported afterward. How do I use Train.Red? The Train.Red sensor is a light-based wearable that you wear directly on your skin. You’re free to place the sensor anywhere on your body but know that this is a hyperlocal metric that will only tell you something about the exact location you place the sensor. We recommend wearing the sensor on a primary involved locomotor muscle, a place on your body that is active during the activity you’re performing. e.g. on your thigh during cycling or squats, the middle part of your upper leg during running, or on your lower arm during climbing. Of course, you are free to use more than one sensor! You can connect up to 4 sensors simultaneously and measure multiple areas at once. You’re not bound to this smartphone application. The Train.Red hardware is integrated into 3rd party apps allowing you to easily synchronise your data from multiple sources. Train.Red sensors can be connected to most Wahoo’s, Garmin’s, Suunto’s and several other devices. More information can be found on our website https://train.red/
Screenshots
Verdict
The clearest difference is rating: Train.Red APP at 5.0 against VO2 Max's 3.8. Train.Red APP also leads on in-app purchases (none vs 3) and iOS requirement (13.0 vs 18.0). VO2 Max's advantage is ratings volume (127 vs 1) and update cadence (every 10 days vs every 3 weeks). On price, ads and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. VO2 Max sells 3 in-app purchases, starting at $2.99 per month. Train.Red APP asks for nothing beyond the download.
Train.Red APP holds the better App Store score, 5.0 against 3.8. That said, the two scores are not equally well evidenced: VO2 Max has 127 ratings behind it against 1, so its average is the more settled of the two.
VO2 Max ships an update every 10 days, Train.Red APP every 3 weeks. The most recent releases landed on September 21, 2026 and July 30, 2026 respectively.
| Parameter | VO2 Max | Train.Red APP |
|---|---|---|
| Price | Free | Free |
| Rating | 3.8 (127 ratings) | 5.0 (1 ratings) — better |
| Positive reviews | 26.6% of reviews | — |
| Number of ratings | 127 — better | 1 |
| Update frequency | Every 10 days — better | Every 3 weeks |
| Ads | No | No |
| In-app purchases | Yes | No — better |
| Monetization | Free with in-app purchases | Free — better |
| Devices | iPhone, iPad, Apple Watch | iPhone, iPad, iPod |
| Requires iOS | 18.0 | 13.0 — better |
| Further details — not scored | ||
| Size | 10 MB | 101 MB |
| Age rating | 4+ | 4+ |
| Developer | Bernhard Hering | Train.Red B.V. |
Customer experience
VO2 Max
Train.Red APP
In-app purchases
VO2 Max
- Monthly Subscription$2.991 Month
- Yearly Subscription$17.991 Year
- Lifetime Access$79.99
Train.Red APP
No in-app purchases









