Heart Rate Monitor for Zwift: How to Fill the Empty HR Box

Short answer: to get your heart rate into Zwift you need a monitor that broadcasts over ANT+ or Bluetooth to whatever actually runs Zwift — your PC, Apple TV, iPad or phone. A sports watch usually only sends its reading to its own app, which is why the heart-rate box in the Zwift pairing screen stays blank. A dual-band chest strap fixes that in seconds.

Why is the heart-rate box empty in Zwift?

It is the most common first-session frustration: power and cadence light up from the turbo trainer, but heart rate stays blank. On a dark, wet October evening when you have finally got the bike on the trainer in the garage or spare room, that empty box is the last thing between you and your first structured session. The usual cause is simple — a wrist watch broadcasts its heart rate to its own phone app over a private connection, not out to Zwift. Zwift can only show data from a sensor it can pair with itself.

A chest strap is designed to broadcast openly, so Zwift sees it straight away in the pairing screen. Damp the electrodes, put it on, open Zwift, and the heart-rate box fills.

ANT+ or Bluetooth for Zwift?

Both work, and this is exactly where a dual-band strap earns its keep. On a Windows PC, ANT+ (via a small USB dongle) is rock solid and lets several devices read the same strap at once. On an Apple TV, iPad or phone, Bluetooth is the route — Apple TV in particular has a limited number of Bluetooth channels, so pairing the strap directly (rather than through extra bridges) keeps things simple. A strap that speaks both protocols means you are never stuck because your platform prefers one over the other.

Do you actually need heart rate for Zwift?

For just riding around, no. For training with intent, yes. ERG workouts and plans lean on heart rate to confirm you are actually loading the right system, and an FTP test is far more meaningful when you can see your heart rate climbing alongside the watts. If you have spent a winter "only watching power", heart rate is the missing half of the picture — it tells you whether an easy day is genuinely easy.

What to look for in a Zwift strap

• Dual-band ANT+ and Bluetooth so it connects to a PC, Apple TV or phone without a rethink.
• Fast, stable pairing that does not drop out when you stand up for a sprint.
• Sweat resistance — indoor sessions are brutal for moisture, so an IP67 rating matters.
• A replaceable coin-cell battery you can buy in any supermarket.

Is a budget strap as good as a Polar H10?

For Zwift, the honest answer is that a well-made chest strap gives you the thing that matters most — a clean, responsive heart-rate trace — at a fraction of the price. The premium straps add extras like on-board memory and multi-connection headroom that most indoor riders never touch. If you want to fill the HR box, follow a plan and stop guessing your effort, an affordable dual-band strap does the job. If you are choosing purely on connectivity, our guide to an ANT+ Bluetooth heart rate monitor goes deeper, and if you are still weighing the wrist against a strap, see chest strap vs wrist heart rate monitor.

The CardIQ strap: made to fill the Zwift HR box

The CardIQ heart rate monitor chest strap is built for exactly this. It is a dual-band strap that broadcasts on both ANT+ and Bluetooth, reads your heartbeat from an ECG-type electrode sensor rather than estimating it from the wrist, and is IP67-rated against sweat and rain. It pairs with Zwift, Garmin and Wahoo head units and a free phone app, runs on a common, user-replaceable CR2032 coin cell, and costs £29.33 inc. VAT (£24.44 ex. VAT). It ships the same day from our UK warehouse with free UK delivery, 30-day returns and a 12-month warranty with UK-based support, and is rated 4.8/5 across 200 reviews.

Frequently asked questions

Do I need a heart rate monitor for Zwift?

Not to ride, but you do to train properly. ERG workouts, training plans and FTP tests all use heart rate to confirm you are working the right zone, so a strap turns Zwift from a game into a structured session.

Does a chest strap work with Zwift on Apple TV?

Yes. Apple TV uses Bluetooth and has a limited number of channels, so a chest strap that pairs directly over Bluetooth is the simplest reliable option. A dual-band strap also covers a PC over ANT+ if you switch setups.

Will a budget chest strap be as accurate as a Polar H10?

For Zwift, a good chest strap gives the same thing that matters: a clean, responsive heart-rate trace read from chest electrodes. The premium models add extras like memory and extra connections that most indoor riders never use.

Can my partner and I both use straps on the same Zwift setup?

Yes. Each strap pairs to its own account or app, so two people can train on one turbo setup with a strap each. Pair them one at a time in the Zwift screen so each rider is linked to the right profile.