# Heart Rate Variability Logger vs AI Endurance

The clearest difference is price: AI Endurance at Free against Heart Rate Variability Logger's $9.99. AI Endurance also leads on rating (4.2 vs 3.5) and review sentiment (67% vs 43%). Heart Rate Variability Logger's advantage is in-app purchases (none vs 2) and update cadence (fortnightly vs every 5 months). On ratings volume, ads, device support and iOS requirement there is nothing between them.

AI Endurance is free to download; Heart Rate Variability Logger costs $9.99 up front. AI Endurance sells 2 in-app purchases, starting at $20.00 per month. Heart Rate Variability Logger asks for nothing beyond the download.

AI Endurance holds the better App Store score, 4.2 against 3.5. Both are backed by a comparable volume of ratings — 19 and 25 respectively. Written reviews point the same way: 43% of Heart Rate Variability Logger's written reviews are positive against 67% of AI Endurance's.

Heart Rate Variability Logger ships an update fortnightly, AI Endurance every 5 months. The most recent releases landed on November 6, 2026 and October 30, 2026 respectively.

## The numbers

| Metric | Heart Rate Variability Logger | AI Endurance |
| --- | --- | --- |
| Price | $9.99 | **Free** |
| Rating | [3.5 (19 ratings)](https://appshunter.io/ios/app/heart-rate-variability-logger/id683984776/reviews) | **[4.2 (25 ratings)](https://appshunter.io/ios/app/ai-endurance/id6714485075/reviews)** |
| Number of ratings | 19 | **25** |
| Positive reviews | 43.1% of reviews | **66.7% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Fortnightly** | Every 5 months |
| Monetization | Paid | **Freemium** |
| Size | 10 MB | 3 MB |
| Requires iOS | 15.6 | **15.0** |
| Devices | iPhone, iPod, Apple Watch | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [A.S.M.A. B.V.](https://appshunter.io/developer/1066843463) | [AI Endurance](https://appshunter.io/developer/1544807340) |

## What reviewers say

### Heart Rate Variability Logger

[App page](https://appshunter.io/ios/app/heart-rate-variability-logger/id683984776)

This app records, plots, and exports heart rate variability data, including time, frequency, and non-linear features. It supports experience sampling, RR-interval correction, and activity/location tracking. Requires a compatible Bluetooth heart rate sensor.

**Highlights:** Record and plot HRV data, Extract time and frequency domain features, Experience sampling for event annotation, Compare multiple recordings, Activity and location tracking, RR-interval correction, Export data for Kubios

**Features:** macOS Compatibility, Apple Watch app, Vision Pro support

**In-app purchases:** none


### AI Endurance

[App page](https://appshunter.io/ios/app/ai-endurance/id6714485075)

This AI-powered fitness coach analyzes your personal data to create a customized training plan. It's designed for athletes looking to optimize their performance and achieve superior results by training smarter.

**Highlights:** AI-powered performance analysis, Personalized training plans, Optimized for unique physiology, Trusted by cyclists, runners, triathletes, Train smarter, not harder

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly Subscription | $20.00 | per month |
| Yearly Subscription | $200.00 | per year |


## Frequently asked questions

### Is Heart Rate Variability Logger free?

Heart Rate Variability Logger costs $9.99, with no in-app purchases.

### Is AI Endurance free?

AI Endurance is free to download, with in-app purchases available.

### Which has better reviews, Heart Rate Variability Logger or AI Endurance?

AI Endurance is rated higher. Heart Rate Variability Logger averages 3.5 out of 5 from 19 ratings, while AI Endurance averages 4.2 from 25 ratings.

### Do Heart Rate Variability Logger or AI Endurance have ads?

Neither Heart Rate Variability Logger nor AI Endurance shows ads.

### Which is updated more often, Heart Rate Variability Logger or AI Endurance?

Heart Rate Variability Logger ships an update fortnightly, and AI Endurance every 5 months. Most recently, Heart Rate Variability Logger was updated on November 6, 2026 and AI Endurance on October 30, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*