POLAR H9 Heart Rate Sensor Chest Strap M-XXL — Bluetooth, ANT+, Waterproof

The POLAR H9 is a waterproof chest-strap heart rate sensor that delivers accurate heart-rate data to phones, watches and gym equipment via Bluetooth, ANT+ and 5 kHz.

Compact and reliable, the POLAR H9 pairs a soft, adjustable strap with a removable sensor module to provide continuous heart-rate monitoring for training, classes, and everyday activity. Compatible with the Polar Flow app and a wide range of third-party apps and devices, H9 supports multiple wireless protocols simultaneously so you can stream your pulse to more than one receiver. With a long-lasting CR2025 battery included and sizes for most torsos, H9 is designed for consistent performance and easy integration into existing fitness setups.

How does the POLAR H9 connect to my phone and gym equipment?

The H9 supports Bluetooth Low Energy, ANT+ and legacy 5 kHz transmission so it can pair with smartphones, multisport watches, bike computers and gym machines. Multiple protocols can be active at once, making it easy to stream to an app and a gym display simultaneously.

• Bluetooth for smartphones and many modern fitness apps (Polar Flow, Strava, etc.).
• ANT+ for bike computers and compatible training devices.
• 5 kHz for legacy gym equipment that still uses analog wireless signals.
• Simultaneous multi-protocol streaming to more than one receiver.

What accuracy and battery life can I expect from the H9?

The chest-strap design places the sensor close to the heart for high-quality R-R interval detection, which many users and researchers prefer over wrist sensors. H9 runs on a replaceable CR2025 button cell that offers roughly 400 hours of use under normal conditions, and the battery is included with the sensor.

• Chest-strap placement for consistent heart-rate signal and R-R interval data.
• Approximately 400 hours of battery life with the included CR2025 cell.
• Replaceable battery—use CR2025 only to avoid damage or malfunction.
• Protective film over the sensor must be removed before first use for accurate readings.

How do I fit, wear, and care for the POLAR H9 chest strap?

The H9 strap is soft and adjustable with two size options to fit most torsos: XS–S for 20"–26" and M–XXL for 26"–36". Fasten the strap snugly below the chest line so the sensors maintain contact with the skin, rinse the strap after sweaty sessions, and detach the sensor for drying and charging or battery replacement.

• Choose strap size: XS–S (20"–26") or M–XXL (26"–36").
• Wear snugly under the pectoral muscles for best signal contact.
• Remove sensor module before washing the strap; rinse and air-dry the textile band.
• Waterproof sensor allows use in rain and sweat, but remove after swimming if pool chemicals require it.

What apps and devices are compatible with the H9?

Because H9 broadcasts standard heart-rate protocols, it works with Polar Flow, popular third-party apps (such as Zwift, Strava and MyFitnessPal-compatible apps), most gym machines, and many multisport watches or bike computers that accept chest-strap HR input.

• Polar Flow for training summaries, program syncing and activity history.
• Third-party fitness apps that accept Bluetooth or ANT+ heart-rate input.
• Gym equipment and indoor bikes supporting 5 kHz or ANT+ reception.
• Ability to pair to multiple apps or devices simultaneously for flexible tracking.

Who is this for: The POLAR H9 suits athletes and everyday exercisers who want reliable chest-based heart-rate data without a high price tag. It's ideal for runners, cyclists, gym-goers and coaches who need accurate pulse and R-R interval readings, multi-device compatibility, and a comfortable strap in a choice of sizes. If you use smartphone apps, compatible watches, or gym equipment and want a straightforward, research-backed heart-rate solution, the H9 is built to integrate into those workflows.