Comparison

Athalyze vs Vitals Sync

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

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.

Highlights
  • 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
Features
Read full description

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

About

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.

Highlights
  • 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
Features
Read full description

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

Athalyze4 screens
Vitals Sync4 screens

Verdict

The call

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

CostPrice · In-app purchases · Ads · Monetization

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.

ReceptionRating · Positive reviews · Number of ratings

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.

UpkeepUpdate frequency

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.

Scorecard6 real differences · 4 level
Athalyze versus Vitals Sync: the parameters behind the verdict, then further details
ParameterAthalyzeVitals Sync
PriceFreeFree
Rating5.0 (5 ratings) — better1.0 (1 ratings)
Positive reviews100.0% of reviews — better0.0% of reviews
Number of ratings5 — better1
Update frequencyEvery 2 weeksEvery 11 days — better
AdsNoNo
In-app purchasesYesNo — better
MonetizationFree with in-app purchasesFree — better
DevicesiPhone, iPad, Mac, Apple Watch — betteriPhone
Requires iOS17.017.0
Further details — not scored
Size71 MB4 MB
Age rating4+4+
DeveloperPerimint LLCUMUR GOKALP

Customer experience

Athalyze

All ratings5 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews1 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

Vitals Sync

All ratings1 ratings
Positive0.0%
Neutral0.0%
Negative100.0%
Written reviews1 reviews
Positive0.0%
Neutral0.0%
Negative100.0%

In-app purchases

2 purchases

Athalyze

Subscriptions2
  • Athalyze Pro (Monthly)1 Month trial$9.991 Month
  • Athalyze Pro (Annual)$99.991 Year
None

Vitals Sync

No in-app purchases

Questions

Is Athalyze free?
Athalyze is free to download, with in-app purchases available.
Is Vitals Sync free?
Vitals Sync is free to download, with no in-app purchases.
Which has better reviews, Athalyze or Vitals Sync?
Athalyze is rated higher. Athalyze averages 5.0 out of 5 from 5 ratings, while Vitals Sync averages 1.0 from 1 ratings.
Do Athalyze or Vitals Sync have ads?
Neither Athalyze nor Vitals Sync shows ads.
Which is updated more often, Athalyze or Vitals Sync?
Athalyze ships an update every 2 weeks, and Vitals Sync every 11 days. Most recently, Athalyze was updated on October 2, 2026 and Vitals Sync on September 19, 2026.

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