This applies on to Moov HR Sweat. No, you do not have to keep your phone with you during a HR Recording workout. Prior to the workout, connect your Moov HR Sweat™ with the Moov Coach app and press “Start Workout”. HR Recording can record up to 2 hours, or 120 minutes, of heart rate data. End the workout using the Moov app on your phone, and upload the data to generate a workout report.
Note: This does not apply to Moov HR Burn. For Moov HR Burn, you need to have your phone with you at all times because the Burn doesn't store memory or data, unlike the Sweat. So you'll need your phone with you while working out and wearing the Burn in order for your heart rate data to be recorded and displayed in real time.