Sense won't track my heart rate accurately

[Dave313]

Whereas my charge 2 gives bpm agreeing with manual watch check, my Sense 3 always gives much higher result . Why?

Moderator Edit: Clarified subject

[JohnnyRow]

For one thing, there is no Sense 3.  Might have meant Sense 2 or Versa 3 (or Charge 3,4,or 5), but common complaint in any case.  I have no good answer.

[MarreFitbit · Accepted solution]

Hello there, @Dave313. Thanks for stopping by in the Community Forums and sharing the details about the issue with your Sense. @JohnnyRow hanks for trying to help!

At times, you might notice slight variations between your heart-rate reading on your Fitbit device versus on another device (such as a chest strap or another wrist-based heart-rate tracker) due to the differences in technologies.

Differences between heart-rate readings on your device and on exercise equipment are likely due to wrist or hand position. Make sure the back of your device is in contact with your wrist and that your band is snug.

Regarding your inquiry about taking into consideration your heart rate while sleeping, please see: What should I know about Fitbit sleep stages?

Additionally, keep in mind that several factors can affect heart rate, including air temperature, stress level, alcohol or caffeine intake, immune response to illness, and medication use (source).

Exercising in cold weather can make it more difficult for your device to track your heart rate, as environmental conditions can affect skin perfusion (the amount of blood that flows through your skin). Spikes in your heart rate during sleep may be caused by sudden movements (for example, waking up and getting out of bed), or a weak signal due to wrist placement. 

As with all heart-rate tracking technology, accuracy is affected by personal physiology, device location on your arm, and type of movement. For a more accurate heart-rate reading:

• Wear your Fitbit device on top of your wrist, and make sure the back of the device is in contact with your skin.
• When you’re not exercising, wear your device a finger’s width above your wrist bone.

• During exercise, wear your device a bit tighter and higher for an improved fit. The band should be snug but not constricting (a tight band restricts blood flow, potentially affecting the heart-rate signal). Many exercises such as bike riding or weight lifting cause you to bend your wrist frequently, which could interfere with the heart-rate signal if the watch is lower on your wrist.

To resolve common issues, see our troubleshooting steps in What factors can affect my heart-rate reading on my Fitbit device?

I've moved your post to the Sense board for organization purposes. 

Hope this helps.