# Norwegian 4x4 Protocol — BEST VO2 & HR MAX TRAINING APP

> HIIT interval training app for VO2 max and heart rate improvement. (iPhone/iPad app by Nikita Yampolski.)

- Source: https://appshunter.io/ios/app/norwegian-4x4-protocol/id6499464775 (this page in markdown: same URL + `.md`)
- Developer: [Nikita Yampolski](https://appshunter.io/developer/1441915166)
- Category: Health & Fitness, Sports
- Price: $5.99 (on sale, was $6.99)
- Rating: 4.40/5 from 49 App Store ratings · 13 written reviews indexed
- Age rating: 4+
- Requires: iOS 17.6 · 5 MB
- Languages: American English
- Released: 2024-05-01
- Data updated: 2026-08-24
- Monetization: paid
- User reviews in markdown: https://appshunter.io/ios/app/norwegian-4x4-protocol/id6499464775/reviews.md

## What is Norwegian 4x4 Protocol?

Norwegian 4x4 HIIT Timer — Interval Training & VO2 Max

BOOST VO2 MAX WITH NORWEGIAN 4X4 PROTOCOL WORKOUTS

Train smarter with the Norwegian 4x4 protocol, one of the most studied HIIT methods for improving cardiovascular performance and endurance. A precise, distraction-free timer guides every interval so you can focus on the effort.

KEY FEATURES:

- Norwegian 4x4 Timer - Precision 4min work / 3min rest cycles
- Heart Rate Training - Track 90-95% max HR zones
- VO2 Max Improvement - Scientifically proven results
- HIIT Interval Timer - Multiple workout protocols
- Progress Tracking - Monitor your fitness transformation
- Universal Training - Running, cycling, rowing, any cardio, you name it
- Offline Ready - No internet required during workouts
- Haptics Feedback and Vibrations
- Countdown before the start
- Customizable Warmup session length
- Customizable Cooldown session length

WHAT IS NORWEGIAN 4 BY 4 TRAINING?

The Norwegian 4x4 protocol is a revolutionary HIIT method featuring:

- 4 intervals of 4 minutes at 90-95% max heart rate
- 3 minutes active recovery between intervals
- Proven results: Increase VO2 max by up to 10% in 8 weeks
- Elite approved: Used by professional athletes worldwide

WHY CHOOSE NORWEGIAN 4X4 INTERVAL TRAINING?

- PROVEN RESULTS: Sports science research shows significant cardiovascular improvements
- BEGINNER FRIENDLY: Complete guide for Norwegian 4x4 workout beginners
- CUSTOMIZABLE: Adapt the Norwegian 4 x 4 protocol to your fitness level
- COMPREHENSIVE: Includes warm-up, cool-down, and recovery protocols
- VALIDATED: Mention in Tim Ferriss' Blog

PERFECT FOR:

- Athletes seeking performance gains with Norwegian 4x4 workouts
- Fitness enthusiasts wanting efficient HIIT interval training
- Anyone improving cardiovascular health through proven protocols
- Runners, cyclists, rowers using Norwegian 4x4 interval training

HOW OFTEN NORWEGIAN 4X4?

- Our app includes guidance on optimal training frequency and recovery for maximum VO2 max gains.

START YOUR NORWEGIAN 4X4 TRANSFORMATION

Join thousands who have revolutionised their fitness with the Norwegian 4x4 protocol training. Download the ultimate Norwegian 4x4 workout app now!

Download today and start training with the Norwegian 4x4.

## Key features

- Precision 4min work / 3min rest cycles
- Heart rate zone tracking (90-95% max HR)
- VO2 Max improvement tracking
- Multiple HIIT workout protocols
- Progress monitoring
- Universal cardio training support
- Offline functionality

## Chart rankings

- #46 in Top Paid · Health & Fitness (US App Store)

## Recent user reviews (10 of 13)

All indexed reviews: https://appshunter.io/ios/app/norwegian-4x4-protocol/id6499464775/reviews.md

### 1/5 — No Details

*2026-03-15*

This app is essentially a timer, there is no guided instruction, which is difficult as a beginner. Also, when the app went in the background, it closed and kept starting over again during my workout. Do not recommend.

**Developer response:** Thanks for the stars, ErnLantry. We have never promised any guided instruction, indeed. It was always meant to be a perfect, simple customer 4x4 timer app with colour-coding.

### 2/5 — Meh

*2026-03-02*

I see why a trial period was not an option, I wouldn’t have purchased. I was expecting a linkage to target heart rates and the Apple Watch pulse reading.

**Developer response:** Thanks for your stars, Meh.
We do connect to Apple Health. Did you allow it on prompt? We really focus on timer and not HR (can be read in your watch). As our triathlon adviser says: “you are not doing a real HIIT if you can still follow the HR rate readings”.

### 3/5 — Why?

*2026-02-03*

I’m not really sure what the point of this app is. It’s a glorified timer. Doesn’t have a watch app and doesn’t give live heart data.

**Developer response:** Thanks for your stars, Alarcahu. Yep. It is a simple timer app, tuned for Norwegian 4x4 protocol with customization.

### 2/5 — User

*2025-12-19*

It has the right times, but no tracking history and goes out when have to use your electronic for  either a phone call or email etc

**Developer response:** Thanks for your stars, Lacypoo! You may click on calories on top of the home screen of the app to see history of the workouts. 

Also get the latest 2.2 version with improvements. 

Merry Christmas and Happy New Year!

### 5/5 — Awesome App with great tech support

*2025-12-06*

Great app backed up with awesome support. I had and issue which was addressed and resolved within 24 hours. That’s top tear performance.

**Developer response:** Thanks for your stars and feedback, Ozorbas! Happy it has solved an issue which surely others will benefit from too. We can make our app better only based a real feedback like yours!

### 5/5 — Simplify 4 x 4

*2025-11-02*

This app handles the timing for 4 x 4 intervals. It is quite simple and works effectively. I have sometimes in the past lost track of which interval I was on this app solves the problem.

**Developer response:** Thanks, Michael. Your stars mean a lot to us! Send us a feedback via website or email on AppStore page for ideas and further improvements. And keep rocking, stay healthy!

### 2/5 — Please don’t bill me again for this

*2025-10-12*

I am not using this app any more. Instead I found a HIIT routine that is a far more effective calorie burner. Also I hate being chained to a timer.

**Developer response:** Thanks for the stars, NikonJunkieGirl! Looks like you just need another product for another use-case. Stay healthy and fit, whatever you choose!

Billing again is a title — well, you pay only once, as you may have noticed — there is no subscription.

### 3/5 — Ok

*2025-08-25*

HR doesn’t fully sync.

**Developer response:** Thanks for your stars, Bellinghamster!

### 1/5 — Doesn’t work

*2025-08-22*

Was excited to use this app but quickly became disappointed when I learned the heart rate doesn’t not sync with app when using Apple Watch.  It remains frozen on the reading for heart rate, which defeats the purpose for this app.  Supports response is they don’t control 3rd party apps.

**Developer response:** Thanks for your stars! As discussed in another channel we have released 1.33 version of the app to fix the issue. It looked like you were ok with an outcome but already wrote this review. Anyway, thanks for trying!

### 5/5 — Jimmy Maher

*2025-07-23*

Love it ! Big help in getting me back to a state of fitness after years of neglecting my wellness

**Developer response:** Jimmy, it means a world to us! Thanks for support! We are also working on an updated version, more modern design, but still same amazing simplicity and sport-agnostic focus. Drop us a line at 4x4@norwegian4x4.com - what triggered you to come back? What sport you do?

## Frequently asked questions about Norwegian 4x4 Protocol

### What is the Norwegian 4x4 Protocol app?

The Norwegian 4x4 Protocol app is designed to guide users through the specific 4-minute work, 3-minute rest interval training method. This protocol is scientifically proven to increase VO2 max by up to 10% in 8 weeks and is used by professional athletes.

### How does the Norwegian 4x4 Protocol app help improve VO2 max?

The app focuses on the core Norwegian 4x4 training method, which involves four intervals of 4 minutes at 90-95% of your maximum heart rate, with 3 minutes of active recovery between each interval. This intense but structured approach is highly effective for boosting cardiovascular capacity.

### Can I use the Norwegian 4x4 Protocol app for different types of workouts?

Yes, the app supports universal training, meaning you can use it for running, cycling, rowing, or any other cardio activity. It provides a customizable warmup session length and haptic feedback for a seamless workout experience.

### Is the Norwegian 4x4 Protocol app suitable for beginners?

The app is beginner-friendly and includes a complete guide for those new to Norwegian 4x4 workouts. It allows for customization to adapt the protocol to your current fitness level, making it accessible for a wide range of users.

### Does the Norwegian 4x4 Protocol app require an internet connection?

No, the app is offline ready, meaning you do not need an internet connection during your workouts. This ensures uninterrupted training sessions regardless of your location or connectivity.

### What is the price of the Norwegian 4x4 Protocol app?

The Norwegian 4x4 Protocol app is available for a one-time purchase of $5.99. This provides full access to all features without any ongoing subscription fees or in-app purchases.

### How often should I use the Norwegian 4x4 Protocol app?

The app includes guidance on optimal training frequency and recovery protocols to help you achieve maximum VO2 max gains. Following this guidance will help you structure your training effectively for best results.

### What devices support the Norwegian 4x4 Protocol app?

The Norwegian 4x4 Protocol app is supported on iPhones and iPads. It is designed for users within the 4+ age rating demographic.

## Version history (last 5 releases)

### 2.5 — 2026-06-10

Visual improvements and fixes based on your feedback. Same focused simplicity for your Norwegian 4x4 sessions. Cooldown 4x4 session wrapper added on users feedback (optional, as warm-up).

### 2.4 — 2026-03-19

Visual improvement and fixes based on feedback from users. Same amazing simplicity and focus on your Norwegian 4x4 HIIT workout.

### 2.3 — 2026-02-24

Visual improvement and fixes based on feedback from users. Some amazing simplicity and focus on your HIIT workout.

### 2.2 — 2025-12-20

Improvements of the background locked-screen mode (thanks, Chris, for the feedback). Same simplicity.

### 2.1 — 2025-12-05

Improvements of the background mode (thanks Chris for a feedback). Same simplicity.

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## More apps by Nikita Yampolski

- [PELMEN](https://appshunter.io/ios/app/pelmen/id1441915167)
- [ncradio.fm](https://appshunter.io/ios/app/ncradiofm/id1507938178)
- [Healing Sounds Therapy](https://appshunter.io/ios/app/healing-sounds-therapy/id6692626903)
- [Mantra Meditation Timer](https://appshunter.io/ios/app/mantra-meditation-timer/id6753276834)
- [InfiniChat AI](https://appshunter.io/ios/app/infinichat-ai/id6755243891)

All apps by Nikita Yampolski: https://appshunter.io/developer/1441915166

## Related topics

[norwegian 4x4 protocol](https://appshunter.io/ios/topics/norwegian-4x4-protocol) · [norwegian 4x4 heart rate](https://appshunter.io/ios/topics/norwegian-4x4-heart-rate) · [norwegian 4x4](https://appshunter.io/ios/topics/norwegian-4x4) · [norwegian 4x4 workout](https://appshunter.io/ios/topics/norwegian-4x4-workout)

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-24.*