---
title: "HIIT 4x4 — App Overview"
url: https://marlvel.ai/apps/hiit-4x4
category: Health & Fitness
developer: Eastridge Technology
platforms: ios
rating: 1.0 (1 ratings)
pricing: paid
report_level: overview
generated: 2026-05-04
last_verified: "2026-05-04T14:23:29.741Z"
---

<!-- SECTION: Key Insight -->
> **Key Insight:** The app provides a specific interval training protocol, though users have reported concerns regarding UI distraction and billing clarity.

<!-- SECTION: Quick Facts -->
| Metric | Value |
|--------|-------|
| Category | Health & Fitness |
| Rating | 1.0 ★ (1) |
| Pricing | paid |
| Platforms | iOS |
| Latest Version (iOS) | 1.08 |
| Developer | Eastridge Technology |

<!-- SECTION: Summary -->
## What is HIIT 4x4?

HIIT 4x4 is an Apple Watch application designed to guide users through structured High Intensity Interval Training sessions. The app utilizes a speedometer-style heart rate monitor to track intensity based on a percentage of the user's Maximum Heart Rate (MHR).

<!-- SECTION: Key Features -->
## Key Features

- **4x4 Interval Sequencing**: Provides a guided workout structure consisting of a 10-minute warmup followed by four cycles of 4-minute high-intensity and 3-minute low-intensity intervals.
- **Speedometer Heart Rate Display**: Visualizes current heart rate against target intensity zones on the Apple Watch interface.
- **Real-time Audio Alerts**: Issues warning chimes when the user's heart rate falls outside of the designated interval target range.
- **MHR Customization**: Allows users to calculate their Maximum Heart Rate using the 220-age formula or by observing peak heart rate during all-out exercise.

<!-- SECTION: Target Audience -->
## Who is it for?

Fitness enthusiasts looking for a structured, heart-rate-monitored interval training routine on their Apple Watch.

<!-- SECTION: Links -->
## Links

- [App Store](https://apps.apple.com/us/app/hiit-4x4/id1450845415?uo=4)
- [Full Intelligence Report](https://marlvel.ai/apps/hiit-4x4)

---
*This is an overview report. Sentiment analysis, competitive landscape, and SWOT analysis are available in the [full intelligence report](https://marlvel.ai/apps/hiit-4x4).*
*Generated by [Marlvel.ai](https://marlvel.ai) — Independent app intelligence.*