# N4x4 vs VO2Max Training

The clearest difference is in-app purchases: N4x4 at none against VO2Max Training's 2. N4x4 also leads on update cadence (every 3 days vs every 11 days). VO2Max Training's advantage is review sentiment (75% vs 67%). On price, rating, ratings volume and ads there is nothing between them.

Both are free to download. VO2Max Training sells 2 in-app purchases, starting at $4.99 per month. N4x4 asks for nothing beyond the download.

On the App Store both sit at effectively the same score — 4.4 for N4x4 against 4.5 for VO2Max Training. Both are backed by a comparable volume of ratings — 17 and 8 respectively. Written reviews are what separate them: 67% of N4x4's written reviews are positive against 75% of VO2Max Training's.

N4x4 ships an update every 3 days, VO2Max Training every 11 days. The most recent releases landed on October 4, 2026 and October 17, 2026 respectively.

## The numbers

| Metric | N4x4 | VO2Max Training |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.4 (17 ratings)](https://appshunter.io/ios/app/n4x4/id6686407796/reviews) | **[4.5 (8 ratings)](https://appshunter.io/ios/app/vo2max-training/id6751254440/reviews)** |
| Number of ratings | **17** | 8 |
| Positive reviews | 66.7% of reviews | **75.0% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Every 3 days** | Every 11 days |
| Monetization | **Free** | Freemium |
| Size | 15 MB | 28 MB |
| Requires iOS | **17.5** | 18.2 |
| Devices | iPhone, Apple Watch | iPhone, Apple Watch |
| Age rating | 4+ | 4+ |
| Developer | [Jan van Rensburg](https://appshunter.io/developer/1688121173) | [Hesam Andalib](https://appshunter.io/developer/6780282869) |

## What reviewers say

### N4x4

[App page](https://appshunter.io/ios/app/n4x4/id6686407796)

This app guides you through the scientifically-backed Norwegian 4x4 HIIT protocol to efficiently boost your VO2 Max and cardiovascular health. It offers set-and-forget workouts with visual and audio cues, suitable for all fitness levels.

**Highlights:** Norwegian 4x4 HIIT protocol, Set-and-forget workout structure, Visual and audio interval cues, Real-time heart rate zone display, 5-minute warm-up, 4 rounds of 4-minute intervals, 3-minute recovery periods

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

**In-app purchases:** none


### VO2Max Training

[App page](https://appshunter.io/ios/app/vo2max-training/id6751254440)

Improve your cardiovascular fitness with science-backed training protocols and real-time coaching. Track your progress, visualize trends, and receive AI-powered insights to enhance your body's oxygen utilization for better health and longevity.

**Highlights:** Science-backed training protocols, Real-time Apple Watch coaching, Progress tracking and visualization, AI-powered personalized insights, Fitness age monitoring, Workout history

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| VO2Max Premium Monthly | $4.99 | per month |
| VO2Max Premium Yearly | $49.99 | per year |


## Frequently asked questions

### Is N4x4 free?

N4x4 is free to download, with no in-app purchases.

### Is VO2Max Training free?

VO2Max Training is free to download, with in-app purchases available.

### Which has better reviews, N4x4 or VO2Max Training?

VO2Max Training is rated higher. N4x4 averages 4.4 out of 5 from 17 ratings, while VO2Max Training averages 4.5 from 8 ratings.

### Do N4x4 or VO2Max Training have ads?

Neither N4x4 nor VO2Max Training shows ads.

### Which is updated more often, N4x4 or VO2Max Training?

N4x4 ships an update every 3 days, and VO2Max Training every 11 days. Most recently, N4x4 was updated on October 4, 2026 and VO2Max Training on October 17, 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.*