Transfer of measurement data related to physical exercise

In this document, a system for processing heart rate measurement data measured during a physical exercise of a user is described. The system comprises a server computer configured to: associate, during a registration procedure for a measurement device of a user, a device identifier of the measurement device with a user account of the user stored in the server computer; receive a device identifier and real-time heart rate measurement data over a network connection; identify the user's measurement device from the received device identifier; store the received heart rate measurement data to the user account of the user on the basis of the association between the received device identifier and the corresponding user account;compute, repeatedly during the physical exercise from the received heart rate measurement data, advanced performance data comprising at least one value which accumulates during the physical exercise; and transmit the computed advanced performance data to the equipment interface unit over the network connection during the physical exercise.