# Heart Rate Zones: Underdog

> Zone 2 Training & Leagues

Canonical page: [https://chrome-stats.com/d/id6758392759](https://chrome-stats.com/d/id6758392759)

## Overview

- **ID:** `id6758392759`
- **Platform:** Apple
- **Type:** Apple app
- **Status:** Available
- **Publisher:** Ignas Velza
- **Category:** Health & Fitness
- **Version:** 1.6
- **Last updated:** 2026-08-18
- **First published:** 2026-03-03
- **Size:** 24 MB
- **Data as of:** 2026-09-05
- **Store listing:** [Apple App Store](https://apps.apple.com/us/app/heart-rate-zones-underdog/id6758392759)
- **Website:** [https://tryunderdog.com](https://tryunderdog.com/)
- **Privacy policy:** [https://tryunderdog.com/privacy](https://tryunderdog.com/privacy)

## Description

Underdog turns your Apple Watch heart rate data into a game. Every minute you spend in Zone 2 — the sweet spot for endurance and fat burning — earns you points. Compete in weekly leagues with friends and climb from Bronze to Diamond.

No manual logging. No ads. Just open the app once and your workouts sync automatically from Apple Health.

WHY ZONE 2?
Zone 2 training (60–70% of your max heart rate) is the foundation of every elite endurance program. It builds your aerobic base, improves VO2 max, and burns fat — without burning you out. The catch: most people train too hard to actually be in Zone 2. Underdog shows you exactly when you're in the zone.

FEATURES
* Automatic Apple Watch sync — workouts appear in seconds
* 5 heart rate zones (Z1–Z5) calibrated to your max HR
* Weekly leagues: Bronze, Silver, Gold, Platinum, Diamond
* Points for every Zone 2+ minute
* Achievements, streaks, and personal records
* Friend leagues — invite via link
* VO2 max tracking from Apple Health
* Works with running, cycling, rowing, hiking, and 40+ workout types

FREE
Underdog is free to use. Optional Underdog Pro unlocks unlimited friend leagues, advanced stats, and custom zones.

TERMS & PRIVACY
Terms of Use (EULA): https://tryunderdog.com/terms
Privacy Policy: https://tryunderdog.com/privacy

Subscriptions auto-renew unless cancelled 24 hours before the end of the current period. Manage in Settings → Apple ID → Subscriptions.

## Rankings

- #2,275,858 — Overall

## Similar extensions and apps

- [Zone 2 – Heart Rate Trainer](https://chrome-stats.com/d/id6761515338)
- [Zone 2 Training Coach](https://chrome-stats.com/d/id6762536918)
- [Zone2 — Heart Rate Zones](https://chrome-stats.com/d/id6775402534)
- [Zone 2: Heart Rate Training](https://chrome-stats.com/d/id6444690892) — 4.60 / 5
- [Zones for Training](https://chrome-stats.com/d/id1139688415) — 4.80 / 5
- [Zone2 Pulse](https://chrome-stats.com/d/id6759531935)
- [Zone2 Fitness](https://chrome-stats.com/d/id6444166065) — 3.00 / 5
- [Zone 2 Training App](https://chrome-stats.com/d/id6776123744)
- [Orange Zones Workout Companion](https://chrome-stats.com/d/id1482990976) — 4.40 / 5
- [Cardio Zones.](https://chrome-stats.com/d/id1103232564) — 4.30 / 5
- [RunnersHeart](https://chrome-stats.com/d/id6758222219) — 5.00 / 5
- [Zone 2 - Fat loss & Endurance](https://chrome-stats.com/d/id6749857232)

---

Source: [Chrome-Stats](https://chrome-stats.com/d/id6758392759)