For your data to be syncronised after your measurement your tablet or smartphone running Android™ or iOS must be switched on and the Bluetooth® connection must be running.
You then just need to open the    ARCHOS Connected Self application on your device for your data will sync to your smartphone or tablet.

Your connected object has onboard storage for a few measurements, so it can sync a few measurements together. If you don't have your smart device with you for a measurement, don't worry it will sync that measurement next time you have your device on and in rage and take a new measurement.