A device for monitoring breathing activity of, e.g., athletes while exercising includes a breathing activity sensor configured to be worn by a wearer and to provide a breathing activity signal indicative of the breathing activity of the wearer. A motion sensor is configured to be worn by the wearer and to provide a motion signal indicative of the motion activity of the wearer. A processing arrangement is coupled to the breathing activity sensor to process the breathing activity signal and produce a processed breathing activity signal. The processing arrangement includes filter circuitry having a first filtering bandwidth and a second filtering bandwidth. The first filtering bandwidth is larger than the second filtering bandwidth. The filter circuitry is coupled to the motion sensor and operates with one of the first filtering bandwidth and the second filtering bandwidth selected as a function of the motion signal from the motion sensor.