Valt Relay

Robert Kinsella

About this app

Valt Relay broadcasts your watch's heart rate over Bluetooth, using the same standard heart rate service a chest strap uses. Anything that reads a chest strap can read your watch instead: training apps, gym equipment, bike computers. Nothing at the other end needs to know what Relay is.

It keeps broadcasting when the screen turns off. Relay shows on your watch face while it runs, so you can see it is still going.

It does not give you heart rate variability or RR intervals. HRV needs the gaps between individual heartbeats, which a wrist sensor cannot measure precisely enough. If HRV matters to you, a chest strap is still the tool for it.

With the screen off, readings update every five seconds rather than every second. That is as often as the watch will deliver them while it sleeps.

Reading the sensor and broadcasting continuously both use power, about as much as tracking a workout does.

There is no account, no sign-in and no phone app. Relay collects nothing and has no internet access: your heart rate goes to the device you paired with and nowhere else.

What’s new

- New: the broadcast stops itself after 15 minutes with nothing listening, so a forgotten one does not drain the battery. Turn it off in Options.
- New: if something on the watch closes Relay mid-broadcast, it says so next time you open it.