Rep The Set

Connecting a heart-rate monitor

Rep The Set reads heart rate from any standard Bluetooth sensor — a chest strap, an armband, or a Garmin watch set to broadcast. Here is how to connect one, and what to do when it will not.

What works

The app is a standard Bluetooth Heart Rate Profile client. In practice that means it works with anything built to the same standard as every other fitness app: chest straps such as the Polar H10 or Garmin HRM-Dual, optical armbands, and Garmin watches with heart-rate broadcasting switched on. There is no list of approved devices and no account to link — if it speaks the Bluetooth heart-rate standard, it works.

Connecting a strap

  1. Put the sensor on first. A chest strap only starts transmitting once it detects skin contact. Damp the electrodes — a dry strap often will not appear at all.
  2. Open Settings, then Heart Rate Monitor. The app asks for Bluetooth permission the first time. It needs it to find the sensor; there is no other way in.
  3. Wait for the name to appear, then tap it. The list refreshes live and sorts by signal strength, so the sensor on your chest should rise to the top within a few seconds.
  4. Watch for the first reading. Pairing is only confirmed when a heart rate actually arrives. If nothing comes through within about twelve seconds, the app gives up rather than showing a device that is connected but silent.

Using a Garmin watch

A Garmin watch can act as the heart-rate sensor, but not by default — it has to be told to broadcast. On the watch, open the controls menu and turn on Broadcast Heart Rate before pairing. Some models list it under Sensors and Accessories. The watch shows a broadcast icon while it is on.

Two things catch people out. Broadcasting usually stops when the watch starts its own activity or goes to sleep, so turn it on again if the connection drops. And a watch that broadcasts only over ANT+ cannot be used at all: the older Forerunner 935 and 235 are the common examples, and they are particularly confusing because they appear in the device list and then fail to pair. Newer models — the Forerunner 945 and 245, the Venu 2 and later — broadcast over Bluetooth and work.

Apple Watch

Apple Watch cannot currently be used as a heart-rate source. This is not an oversight: watchOS does not let a watch broadcast live heart rate over Bluetooth to a third-party iPhone app the way a strap or a Garmin does. Reading it live would need a companion watch app, which is on the list but not built.

If you train with an Apple Watch today, a chest strap paired to the phone is the way to get live heart rate and time in zone in Rep The Set.

When it will not connect

The name is in the list but pairing fails

Appearing in the list only means the device is advertising over Bluetooth. It does not mean it can send heart rate. The app checks for the heart-rate service after you tap, and reports a failure if the device does not have one. Older Garmin watches are the usual cause — see below.

It paired once and will not reconnect

The app remembers the sensor and scans for it on the next workout, but gives up after about thirty seconds so it is not draining your battery searching for something that is switched off. Put the strap on, then reopen the screen. For a watch, turn broadcasting on again — most models stop broadcasting when the workout ends or the watch sleeps.

It connects to my watch but not the phone

Most chest straps hold one Bluetooth connection at a time. If a watch or bike computer has already claimed it, the phone will not see it. Disconnect it there, or turn that device off, and try again.

Readings stop partway through a workout

Usually the strap drying out, the battery going, or the phone moving out of range. Bluetooth range drops sharply through a body, so a phone on the floor behind you is a harder path than one on a bench in front.

What you get once it is connected

Live heart rate on the run screen, and a recording of every second of the session. That is what the zone breakdown, the heart-rate trace and the pacing analysis are all built from — see what your heart-rate zones mean for how to read them, or the full feature list.