Heart rate measurements on my HUAWEI wearable device are inaccurate

How the wearable device measures your heart rate

Your heart rate is measured with the optical heart rate sensor on the back of your wearable device, which measures the blood flow changes in your wrist by emitting light on your skin, and receiving how much light is reflected back.

Inaccurate measurements during daily use

1. Wear your watch/band in a correct manner.

   

   1. Wear the device with the screen facing upwards.
   2. Wear the device one-finger width above your wrist bone.
   3. Do not wear the device too tightly or loosely, to ensure a comfortable fit and ensure that the sensor works as normal. If the skin under the device moves when you move the device, this indicates the right tightness.
   4. Ensure that your wrist does not shake during a heart rate measurement. Otherwise, the receiving of optical signals by the sensor will be affected, resulting in inaccurate heart rate measurements.
   5. If you are interested in fitness and exercise frequently, it is recommended that you use a soft rubber strap (fluoroelastomer, silicone, or TPU). This can ensure optimal contact between your wearable device and your wrist, to achieve optimal performance when using the optical heart rate sensor.
2. Enable Continuous heart rate monitoring.

   For optimally accurate heart rate data, go to Health monitoring in the Huawei Health app, enable Continuous heart rate monitoring, and enable Real-time mode. (If your wearable device does not support Continuous heart rate monitoring in Real-time mode, it will measure your heart rate periodically based on your activity.)

   

3. Physical condition

   The sensor may fail to receive the reflected light if your fitness level is low, or you suffer from a weak heartbeat, clogged blood vessels, or heart disease. As a result, the heart rate data display may be abnormal, or inaccurate heart rate measurements may occur. It is recommended that you tighten the strap or use a medical device to conduct heart rate measurements.

   

   All monitoring data and results from your watch/band are for reference only, and should not be used as a basis for medical diagnosis or treatment.

4. Body features

   The light may fail to reach the sensor if there are tattoos, scars, or a lot of hair on your wrist. As a result, inaccurate heart rate measurements may occur. For optimal performance, wear the watch on an arm without tattoos or scars.

Inaccurate measurements during workouts

1. Wear your watch/band in a correct manner.

   For precautions on watch wearing, please refer to here.

2. Select the correct workout type.
   • Select the same type of workout as the one you are engaged in. The heart rate calculation method varies for each workout type and is most accurate when the workout type matches your actual workout.
   • Workouts involving wrist-bending actions, such as jump roping, strength training, push-ups, weightlifting, and racket sports, may compress blood vessels, affecting the accuracy of the heart rate sensor. You can wear your watch slightly above your wrist, or use a heart rate strap during these workouts.
   • You can obtain more accurate heart rate measurements during regular workouts (such as running, walking, and cycling).
   

   The displayed data may change significantly after you complete a workout. This is because your heart rate tends to decrease significantly in this scenario, which is normal and does not indicate any issue with your wearable device.

3. Make sure that the optical heart rate sensor is clean.

   The optical heart rate sensor is vulnerable to fragments and accumulated objects, and therefore, may fail to receive the reflected light, affecting data accuracy. It is recommended that you clean the wearable device after each workout, especially when you use sunscreen, lotion, or insect repellent. Use warm water and a soft cloth to wipe the optical heart rate sensor. Rinse the watch to remove residues, and let it dry, before putting it on again. For more cleaning and maintenance information, please refer to Cleaning and maintenance guide for wearables.

4. Winter or low-temperature scenarios

   When the temperature is lower than 15°C, the capillaries on your wrist narrow, which may lead to reduced blood flow in the back of your wrist. This may occur in the early stages of workouts when the blood flow is low, making it hard for the heart rate sensor to obtain valid data. It is recommended that you warm up for about 10 minutes before starting a workout. You can also use a heart rate strap in this scenario for optimally accuracy if needed.

5. Restart your watch.

   Restart your watch regularly, and once a week is recommended.

6. Update to the latest versions.

   Newer versions feature better algorithms. Please update your wearable device and the Huawei Health app to their latest versions at your earliest convenience.

Inaccurate measurements compared to medical devices

HUAWEI wearable devices are generally compared against the gold standard (ECG) with an error range of ±10 bpm. If your heart rate is lower than 37 bpm, your wearable device's heart rate monitoring will not be useful. In this case, it is recommended that you use a medical device to check your heart rate.