A portable device (1), method and program product eneratea parameter related to the physical activity of a user. The device (1) includes a sensor (2) configured to measure information representative of the movement of the user. The sensor (2) is configured to generate, on the basis of such information, values of physical activity data. A data processing unit (3) operatively connected to the sensor (2), is configured to generate at least one physical activity rate parameter on the basis of the values of physical activity data generated by the sensor (2). The data processing unit (3) generates the at least one physical activity rate parameter in a first reference time instant on the basis of a portion of values of the values of physical activity data generated by the sensor (2) in a set period of time preceding the first reference time instant.
