The invention relates to wearable electronic equipment and method for measuring heart rate or muscular activity of a person. The equipment comprises one or more heartbeat or muscular activity sensors for providing a heartbeat or muscular activity signal, respectively, and a motion sensor for providing a motion signal corresponding to movement of the person. In addition, there are provided processing means for detecting from the heartbeat or muscular activity signal first events corresponding to individual heartbeats or muscle activations, respectively, and from the motion signal second events corresponding to movement changes stronger than a predefined threshold. The processing means are further programmed to form a first time series of said first events, and to determine the heartbeat or muscular activity parameter using the first time series. According to the invention, the processing means are programmed to omit from said first time series those first events that coincide with and/or take place at the same frequency as the second events. The invention helps to remove motion-induced artifacts from ECG and EMG signals for more accurate sports performance monitoring and characterization.
