Optical sensor light leak under wrist
Wearing a fitness tracker on the underside of the wrist introduces noise because tendons running to the fingers cause light leak in the optical sensor.
Where this was said
Fitbit Air Gets an Official Accessory Ecosystem
At 17:59 · chapter starts 13:30
A social media trend of attaching traditional watches to the Fitbit Air strap — popularized partly by a photo from Dan Seifert, now at Google — has convinced Google to release official Fitbit Air hardware specs. This opens the door for third-party makers to build adapters, straps, and even bicep attachments. The hosts geek out on the potential: Andrew wants notifications from it, Adam is already dual-wristing without drama, and David imagines a future where swappable Fitbit Air bands cost under $30 each. The segment reveals a fundamental tension between minimalist wearables and feature creep that the hosts can't quite resolve.
The Optical Sensor Wrist Science Explained
Wearing an optical fitness tracker on the underside of the wrist introduces significant data noise. The tendons running through your fingers constantly break the light seal the sensor needs, causing light leak — while the top of the wrist offers stable muscle tissue for a clean reading.
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