An apparatus comprising: a wireless interface configured to provide a wireless device-to-device connection with a heart rate measurement device ; a network interface configured to provide the apparatus with a network connection; at least one processor ; and at least one memory including a computer program code , wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus to: receive , at a beginning of an exercise carried out by a user, a device identifier from the heart rate measurement device attachable to the user's body; receive, from the heart rate measurement device through the wireless interface, a network address of a server computer to which to route heart rate measurement data acquired from the heart rate measurement device during the exercise; receive said heart rate measurement data from the heart rate measurement device through the wireless interface during the exercise; and cause the network interface to transmit the device identifier and the heart rate measurement data through the network connection to the network address of the server computer, wherein the server computer uses the device identifier to store the heart rate measurement data to a correct user account. a wireless interface configured to provide a wireless device-to-device connection with a heart rate measurement device ; a network interface configured to provide the apparatus with a network connection; at least one processor ; and at least one memory including a computer program code , wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus to: receive , at a beginning of an exercise carried out by a user, a device identifier from the heart rate measurement device attachable to the user's body; receive, from the heart rate measurement device through the wireless interface, a network address of a server computer to which to route heart rate measurement data acquired from the heart rate measurement device during the exercise; receive said heart rate measurement data from the heart rate measurement device through the wireless interface during the exercise; and cause the network interface to transmit the device identifier and the heart rate measurement data through the network connection to the network address of the server computer, wherein the server computer uses the device identifier to store the heart rate measurement data to a correct user account. receive , at a beginning of an exercise carried out by a user, a device identifier from the heart rate measurement device attachable to the user's body; receive, from the heart rate measurement device through the wireless interface, a network address of a server computer to which to route heart rate measurement data acquired from the heart rate measurement device during the exercise; receive said heart rate measurement data from the heart rate measurement device through the wireless interface during the exercise; and cause the network interface to transmit the device identifier and the heart rate measurement data through the network connection to the network address of the server computer, wherein the server computer uses the device identifier to store the heart rate measurement data to a correct user account. <EOS>