Fitbit device. Pic courtesy/YouTube

Health and fitness wearables firm Fitbit validated the ability of its wrist-worn trackers that incorporate movement and cardiac sensors to accurately determine sleep stages -- light, deep and rapid eye movements (REM), the company said in a statement on Thursday.

The results demonstrate that the recently launched devices like Fitbit Alta HR, Blaze and Charge 2 can be used to track sleep stages with a reasonable degree of accuracy in normal adult sleepers.