Heart Rate Alerts: High & Low Thresholds

Beat Watcher lets you set both a high and low heart rate threshold on your Apple Watch. When your BPM crosses either limit, you get instant haptic vibration and audio feedback. Here’s how to set them up.

Setting your high threshold

The high threshold alerts you when your heart rate goes above a BPM you choose. This is the main threshold you see on the Beat Watcher home screen.

1

Open Beat Watcher

Your current heart rate and threshold are displayed on the main screen.

2

Turn the Digital Crown

Turn the Digital Crown to adjust the threshold to your desired level. Range: 30–250 BPM.

3

Done

Your threshold is saved automatically. Beat Watcher will provide haptic and audio feedback when your heart rate goes above it.

Beat Watcher showing 72 BPM with threshold set to 80

Adding a low threshold

Low Alerts notify you when your heart rate drops below a value you set. Useful for monitoring bradycardia or staying aware of significant heart rate drops during rest or sleep.

1

Open the menu

Tap the top part of the screen that shows your heart rate and threshold.

2

Enable Low Alerts

Tap Settings, then tap Low Alerts. Turn on the Low Alerts toggle.

3

Set your level

Use the Digital Crown to adjust between 30–110 BPM. You’ll receive haptic and audio feedback when your heart rate drops below this value.

Beat Watcher Low Alerts editor

Choosing the right thresholds

The best thresholds depend on what you are using Beat Watcher for:

Medical monitoring

For POTS or ME/CFS pacing, consult your doctor. Common starting points are resting HR + 30 BPM for POTS, or (220 – age) × 0.6 for ME/CFS.

Stress awareness

For stress monitoring, set your high threshold 15–25 BPM above your resting heart rate.

Fitness and sauna

Set it to your target zone ceiling. For sauna sessions, 140 BPM is a common exit threshold.

Dual coverage

Set a high threshold of 120 BPM and a low threshold of 50 BPM to be alerted when your heart rate goes outside that range in either direction.

How it compares to Apple’s built-in notifications

Apple Watch has built-in high and low heart rate notifications, but they check periodically and are delayed. Beat Watcher provides:

  • Instant alerts with continuous monitoring in Background Mode
  • Fully customizable thresholds (any BPM you choose, vs. Apple’s preset options)
  • Persistent Alerts that repeat every few seconds while past threshold
  • Haptic + audio feedback directly on your wrist
  • Phone Alerts that forward threshold crossings to your iPhone, with Critical Alerts to cut through Do Not Disturb

Try Beat Watcher on your Apple Watch

Requires Apple Watch Series 3 or newer (watchOS 8+).

Download on the App Store
Beat Watcher on Apple Watch

Frequently Asked Questions

What range can the high threshold be set to?

The high threshold can be set from 30 to 250 BPM using the Digital Crown.

What range can Low Alerts be set to?

Low Alerts can be set from 30 to 110 BPM using the Digital Crown.

Can I use both high and low thresholds at the same time?

Yes. The high threshold and Low Alerts work simultaneously. For example, you might set your high threshold to 120 BPM and your low threshold to 50 BPM to be alerted when your heart rate goes outside that range.

What happens when my heart rate crosses a threshold?

Beat Watcher will provide haptic and audio feedback when your heart rate goes above or below the set threshold. If Persistent Alerts are enabled, the feedback repeats every few seconds as long as your heart rate remains past the threshold.

How is this different from Apple Watch’s built-in notifications?

Apple Watch’s built-in heart rate notifications check periodically and are delayed. Beat Watcher provides instant alerts with fully customizable thresholds and works continuously in Background Mode. You can set the exact BPM level that matters to you.

Does the threshold persist after closing the app?

Yes. Your threshold is saved automatically and will be the same when you open Beat Watcher next time.

Related: Background Mode Guide · Phone Alerts Guide · POTS Heart Rate Monitor