How to avoid heart rate inaccuracy?

1) Not wear it properly

Inaccurate heart rate readings appears to be due to the fit of the device band itself. A loosely fitting band that moves around at all, or that has notable gaps between the device and the skin, can easily cause an inaccurate reading. For the most accurate heart rate readings, you will want to be sure you’re wearing the device on the top of your wrist and it's fairly snug against your skin.

2) irregular movements

Rhythmic movements, such as running or cycling, give better results compared to irregular movements, like tennis or boxing. We advises tightening your watch band for workouts to reduce any chance of false readings, then loosening it when you’re done.

3)Skin perfusion/environment affect performance

As the heart rate sensor is basically a pulse oximeter which monitors the perfusion of blood to the dermis, it’s prone to inaccuracies.That’s because skin perfusion — a measure of how much blood flows through your skin — varies significantly from person to another.

Especially the ones who have dark skin, hairy wrists, tattoo, and scar.

4)Light sensors on the back of the device are obstructed

If you’re seeing a reading that doesn’t look quite right, please check the following:

1)Take a second measure if you thought the reading isn't right. 

2) Keep it close to your skin

3) Clean the heart rate sensor

Soak a cotton swab with rubbing alcohol and clean the surface of the sensor on the back of the device.

Make sure that no debris from the swab is left behind.

Wipe with a dry cloth or tissue.