How to connect a chest strap to your watch

Put the strap on before you do anything else. The makers' pages keep pointing at two culprits: a strap that isn't awake, or a strap already talking to something else.

I don't test devices and I haven't paired any of these myself. The steps below come from each maker's support pages, checked as of 3 November 2026. Menus change with firmware, so if yours doesn't match, your watch's manual wins.

ANT+ and Bluetooth, briefly

They're two wireless standards. Your strap may have both, and your watch may not.

The practical bit is the Bluetooth limit. A strap only has so many Bluetooth connections. Once your phone app has taken one, your watch or Zwift may not see the strap at all. If a strap has ANT+ and your watch or trainer setup does too, ANT+ is the easy way to avoid that clash.

Wake the strap

The strap needs skin contact to start. Garmin's Forerunner 570 manual says to wake the sensor first, and Polar says you must moisten the strap and wear it to pair it. Moisten the electrode areas, fasten it snugly and check they sit firmly against your skin.

Pair with a Garmin watch

From the Forerunner 570 manual. Other models may word it differently.

1. Stand within 3 m (10 ft) of the strap, and 10 m (33 ft) from other wireless sensors. A gym can be a poor place to do this.
2. From the watch face, hold the middle-left button.
3. Select Watch Settings, Connectivity, Sensors & Accessories, Add New.
4. Choose Search All or your sensor type.
5. Wait for the status to change from Searching to Connected.

After that, it connects by itself when you start an activity and the sensor is in range.

Pair with a Polar watch

Polar's support page gives this route:

1. Go to Settings, General Settings, Pair and sync.
2. Choose Pair sensor or other device.
3. When it finds your strap, with an ID like Polar H10 xxxxxxxx, press OK.
4. Wait for Pairing completed.

Polar's H10 manual also says to pair the strap with the Polar Flow app first, for firmware updates, and to do it through the app and not your phone's Bluetooth settings. Want it serving two Bluetooth devices at once? Polar's FAQ says you can usually use it with one at a time, but in Flow you can tap the cogwheel and turn on "2 Bluetooth devices".

Pair with a Coros watch

Coros's support site refused my plain requests, so I read its Heart Rate Monitor FAQ only through search results. Treat this as less firmly checked than the rest.

Go to System, Accessories, Add Bluetooth, and select the sensor while wearing it. Coros says the data field shows "EXT" when the external sensor is connected, and that a paired strap disables the watch's optical sensor for that activity. The table above shows what the Pace 4 takes. Check your own model before you buy a strap for it.

Strava: two routes

If you record on a watch, you don't pair the strap with Strava at all. The strap talks to the watch, and the activity syncs later. For Garmin, Strava's support page says: in the app, open Settings on the You tab, select Connect an App or Device, then Garmin, then sign in and accept the permissions. If an activity doesn't appear, check that the Activities permission is on in Garmin Connect.

If you record on your phone, Strava (version 169 or higher) supports Bluetooth Low Energy heart-rate monitors.

1. Select Record.
2. Slide the menu up and select Add a Sensor.
3. Wake the strap, tap it when it appears, then select Done.

Strava says it has no plans to add ANT+ to its app. So an ANT+-only strap won't work there, and all three straps in the table above do have Bluetooth. Strava's advice if it won't connect: toggle Bluetooth off and on, check the strap's battery, and make sure it hasn't paired with another device in range.

Zwift

Zwift's support page, updated in September 2026, says you can connect any monitor that broadcasts over Bluetooth Low Energy or ANT+.

1. If connecting manually, connect your trainer, power meter or speed sensor first.
2. On the Paired Devices screen, select Heart Rate.
3. Select your strap from the list.
4. On the Sensor Data Consent screen, select I Consent, then Close.

Zwift warns that a strap connected to another app or device may not be detected. If you see the Trainer Bridge icon, your trainer can relay the heart rate, and you can pick either route.

If it still won't show up

Work down this list:

• Are you wearing it, with damp electrodes?
• Is the phone's Bluetooth holding on to it? Close the other app, or turn Bluetooth off for a moment.
• Do you still have a free connection on the strap?
• Is the battery alive?
• Does your watch actually support that standard? A Bluetooth-only watch won't use a strap's ANT+.

Is it worth the bother?

For steady runs, perhaps not. For intervals, lifting and hard bike sessions, I think so. In Gillinov's 2017 peer-reviewed study of 50 healthy adults (abstract read, funding unchecked), a Polar H7 chest strap reached rc 0.996 against ECG, while wrist and forearm devices ran from 0.92 down to 0.67. Those are old models and the ranking doesn't transfer. I found no equivalent figure for current watches. Why wrist heart rate fails in hard sessions goes through it.

To choose a strap, see Polar H10 vs HRM 600 vs Wahoo TRACKR or the gym and cycling picks.