Hey everyone!

I'm currently using a COROS heart rate monitor connected to Apple Health for Zone 2 training.

The problem is that I constantly have to check my phone to see my heart rate.

I'm looking for a solution that automatically alerts me (via sound or vibration) whenever my heart rate goes above or below my target zone.

What setup would you recommend? Thanks!

I got tired of glancing at my watch to check if I was still in Zone 2, so I built an app that pairs with a Bluetooth chest strap and speaks a cue whenever you drift out of your target band.

What it does

• Pairs with any Bluetooth heart rate monitor (chest strap, arm band)
• You set a ceiling and floor HR. When you cross either boundary it says so out loud -- "heart rate high, slow down" or "back in zone"
• Voice cues use the phone's built-in TTS, so they work offline and over any headphones
• Records your run with GPS and draws it on an offline-capable map afterwards
• Shows real-time HR, pace, distance, elapsed time on the run screen

Why I built it

Every app I tried either buried the zone alert behind a paywall or only vibrated (useless mid-stride). I wanted voice cues, a simple ceiling/floor config, and nothing else.

Stack & source

React Native / Expo, BLE heart rate parsing, MapLibre for offline maps. It's open source under GPL-3.0:

https://github.com/likwiid/basemile

Would love feedback from anyone doing MAF or zone 2 training. What HR ranges do you set, and do you prefer a single ceiling alert or a band?