A method of counting steps of a user employs a first device, e.g. a personal activity monitor 1) and a second device, e.g. a smartphone 2) which communicate with each other. The method includes detecting and counting the steps of the user by the first device, detecting and counting the steps of the user by the second device, transferring step data from one of the two devices to the other of the two devices, and identifying at least a first time period (Tw) for which a difference in the number of steps counted by the first device and by the second device is greater than a predetermined threshold (S). The method further includes supplementing the step data recorded for the first time period in one of the two devices with the step data from the other of the two devices.