Athalyze vs Vitals Sync
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Athalyze
This platform unifies workout data from multiple devices, creating a single, accurate activity log. It allows users to compare metrics across devices, track personal bests, and visualize training trends for improved performance. Features include gear tracking and multi-device step challenges.
- Combine multi-device workout recordings
- Select best data per metric for accuracy
- Compare metrics across devices on one chart
- Track personal records and best efforts
- Visualize training curves and histograms
- Monitor gear usage and mileage
- Create and join multi-device step challenges
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Athalyze is a training log for athletes who wear more than one device. It runs on iPhone, iPad, Apple Watch and Mac. Run with an Apple Watch and a Garmin, or ride with a bike computer while wearing an Oura ring, and Athalyze merges the recordings into one activity. It works with Apple Watch, Garmin, Whoop, Oura, and Google Health devices like Pixel Watch and Fitbit. For each metric it picks the most reliable data, and it keeps the originals so you can see where every number came from. Multi-Device Merging • Recordings of the same workout are combined automatically • Set device priority for each metric if you prefer one source • Compare devices on one chart, each in its own color. Tap a swatch to show or hide it • Import FIT files, including Garmin developer fields like core body temperature • See when a recording switches source, such as heart rate moving from Apple Watch to AirPods Pro • Press play on the map to fly along your route while the charts follow • Two Apple Watches, or a watch and a sleep app like Pillow or AutoSleep, each keep their own heart rate, HRV, sleep and vitals Vitals • Last night's HRV, resting heart rate, respiratory rate, SpO2, skin temperature and sleep on one screen • HRV is shown as RMSSD, the measure Garmin, Oura and Whoop use, including Recovery HRV from the newest Apple Watch models. You can also view it as SDNN if your devices record it • Each vital is compared with your own normal range, and you get a morning alert when one falls outside it • Steps and blood glucose are charted against your normal range too Training Load • Fitness, Fatigue and Form from every workout, whichever device recorded it • Scored from power, pace or heart rate, with thresholds estimated from your own efforts • Form updates through the day and projects forward to show what a rest day would do Records and Analysis • Best efforts from short intervals to ultra distances, and best power from a few seconds to an hour • Filter by sport and time period • Power and pace curves, with time periods compared on one chart • Correlation heatmaps show how two metrics relate, like pace and stride length, and how that has changed between two periods • Histograms show how your pace, power, stride length or temperature is distributed, and how that shifts over time Apple Watch • See today's steps against your typical day, plus daily, weekly and monthly trends • Check last night's vitals against your normal range • Follow your training load Fitness, Fatigue and Form • Browse recent activities, activity trends and your personal records • Check challenge leaderboards • Put Form on your watch face as a number or a gauge, and follow a challenge from the Smart Stack Gear and Devices • Track mileage on shoes, bikes and other gear, and see which workouts used each one • See every device you've used and the activities it recorded • Follow battery levels, and get a notification when a battery runs low Challenges • Step challenges with friends and family, whatever device each person wears • Switch devices during the day and your total stays right. Wearing two at once doesn't count steps twice • Get a notification when your place changes Terms of service: https://www.athalyze.com/terms Privacy policy: https://www.athalyze.com/privacy
Vitals Sync
This app imports key health metrics from your Garmin device that are not automatically synced to your phone's health app. It securely transfers HRV, Respiration, SpO₂, and VO₂ Max data directly from your device.
- Syncs HRV, Respiration, SpO₂, and VO₂ Max
- Automatic background sync
- No duplicate entries
- Secure token-based authentication
- On-device processing
- No app account or tracking
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Vitals Sync imports four metrics your Garmin records but does not send to the Health app: HRV, Respiration, SpO₂, and VO₂ Max. Everything runs on your device. You sign in with your Garmin Connect account. The app reads the data your Garmin watch already recorded and writes it to the Health app on your iPhone. Most syncing tools cover only HRV. Vitals Sync does all four. WHAT YOU NEED • A Garmin Connect account • A Garmin watch that records these metrics, like the Forerunner, Fenix, Venu, vívoactive, Instinct, Epix, or Enduro series, and more WHAT IT SYNCS • Heart Rate Variability (HRV) • Respiration rate • Blood oxygen (SpO₂) • VO₂ Max FEATURES • Automatic background sync • No duplicates. Every reading is written once. • Your password is not stored. Only secure tokens, kept in the iOS Keychain on your device. • No account for this app, no tracking, no analytics, no servers PRIVACY Vitals Sync has no backend. It talks directly from your iPhone to your own Garmin account and to the Health app. We never see, collect, or store your data. Vitals Sync is an independent product and is not affiliated with, endorsed by, or sponsored by Garmin Ltd. or its subsidiaries, or by Apple Inc. Garmin® is a registered trademark of Garmin Ltd.
Screenshots
Verdict
The clearest difference is review sentiment: Athalyze at 100% against Vitals Sync's 0%. Athalyze also leads on rating (5.0 vs 1.0) and ratings volume (5 vs 1). Vitals Sync's advantage is in-app purchases (none vs 2). On price, update cadence, ads and iOS requirement 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. Athalyze sells 2 in-app purchases, starting at $9.99 per month. Vitals Sync asks for nothing beyond the download.
Athalyze holds the better App Store score, 5.0 against 1.0. That said, the two scores are not equally well evidenced: Athalyze has 5 ratings behind it against 1, so its average is the more settled of the two. Written reviews point the same way: 100% of Athalyze's written reviews are positive against 0% of Vitals Sync's.
Athalyze ships an update every 2 weeks, Vitals Sync every 11 days. The most recent releases landed on October 2, 2026 and September 19, 2026 respectively.
| Parameter | Athalyze | Vitals Sync |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (5 ratings) — better | 1.0 (1 ratings) |
| Positive reviews | 100.0% of reviews — better | 0.0% of reviews |
| Number of ratings | 5 — better | 1 |
| Update frequency | Every 2 weeks | Every 11 days — better |
| Ads | No | No |
| In-app purchases | Yes | No — better |
| Monetization | Free with in-app purchases | Free — better |
| Devices | iPhone, iPad, Mac, Apple Watch — better | iPhone |
| Requires iOS | 17.0 | 17.0 |
| Further details — not scored | ||
| Size | 71 MB | 4 MB |
| Age rating | 4+ | 4+ |
| Developer | Perimint LLC | UMUR GOKALP |
Customer experience
Athalyze
Vitals Sync
In-app purchases
Athalyze
- Athalyze Pro (Monthly)1 Month trial$9.991 Month
- Athalyze Pro (Annual)$99.991 Year
Vitals Sync
No in-app purchases









