What is confidence-gated storage, and does it affect Fitbit Air accuracy?

Confidence-gated storage means the Air only writes a data point to the file when the optical signal meets an internal quality threshold. During wrist sport, the stored interval stretches to approximately 5 seconds, yielding roughly one-fifth as many data points as competing devices. The statistics describe only the data points the device chose to keep.

Does wearing the Fitbit Air on the bicep improve accuracy?

Yes, significantly. Bicep placement improves both signal quality and data storage density, with the storage interval dropping from approximately 5 seconds on the wrist to 2.4 seconds on the bicep. Bias against a chest-strap reference drops to near zero, with a limit of agreement of ±4.9 bpm.

Can the Fitbit Air broadcast heart rate to a Garmin or Wahoo device?

No. The Air uses a proprietary Bluetooth implementation covering Peloton and Concept2. Garmin bike computers and Wahoo head units require the standard Bluetooth HR profile, which the Air does not support.