• Daily Mail, Friday, January 8, 2016 11:18 AM

The world's bestselling fitness tracker manufacturer is facing a US lawsuit against claims that its wristband can monitor owner's heart rates are wildly - and potentially dangerously - inaccurate. Claims have been made by fitbit owners from several US states, with one saying that fitbits 'do not and cannot consistently and accurately record wearers' heart rates during the intense physical activity for which Fitbit expressly markets them'. One claimant described how her personal trainer measured her heart rate at 160 beats per minute but her Fitbit Charge HR recorded a rate of 82 bpm