A method for providing a personal training data service with Bluetooth devices, the method comprising: associating each personal training data item with a unique identifier and associating each unique identifier of said each personal training data item with a handle identifier specifying location of the personal training data item in a database of the personal training data service; initiating, in a first Bluetooth device (102, 104, 106, 110, 120, 122) connection establishment with a second Bluetooth device (102, 104, 106, 110, 120, 122); carrying out a service discovery procedure with the second Bluetooth device, during which at least one unique service identifier associated with the personal training data service is exchanged between the first Bluetooth device and the second Bluetooth device, wherein the personal training data service comprises at least one personal training data item processed by the first Bluetooth device and/or the second Bluetooth device during a physical exercise; exchanging a unique identifier of the at least one personal training data item during the service discovery procedure so as to determine the at least one personal training data item associated with the personal training data service; exchanging a structure of the database during the service discovery procedure by exchanging said handle identifiers of the at least one personal training data item stored in the database; after the service discovery procedure, transferring at least one frame with the second Bluetooth device, wherein the frame comprises an information element specifying personal training data and a command information element specifying a data processing operation, wherein the at least one frame is arranged to comprise a handle identifier specifying a personal training data item referred to by the data processing operation. associating each personal training data item with a unique identifier and associating each unique identifier of said each personal training data item with a handle identifier specifying location of the personal training data item in a database of the personal training data service; initiating, in a first Bluetooth device (102, 104, 106, 110, 120, 122) connection establishment with a second Bluetooth device (102, 104, 106, 110, 120, 122); carrying out a service discovery procedure with the second Bluetooth device, during which at least one unique service identifier associated with the personal training data service is exchanged between the first Bluetooth device and the second Bluetooth device, wherein the personal training data service comprises at least one personal training data item processed by the first Bluetooth device and/or the second Bluetooth device during a physical exercise; exchanging a unique identifier of the at least one personal training data item during the service discovery procedure so as to determine the at least one personal training data item associated with the personal training data service; exchanging a structure of the database during the service discovery procedure by exchanging said handle identifiers of the at least one personal training data item stored in the database; after the service discovery procedure, transferring at least one frame with the second Bluetooth device, wherein the frame comprises an information element specifying personal training data and a command information element specifying a data processing operation, wherein the at least one frame is arranged to comprise a handle identifier specifying a personal training data item referred to by the data processing operation.