Impact-sensing and measurement systems are disclosed, especially for use in contact sports and related activities that involve exchanges of impacts or blows. The system generally includes at least one impact sensor, a controller, and a feedback device. The controller is in communication with the at least one impact sensor, and includes a microprocessor having a control program software executed thereon at least for processing data from the at least one impact sensor. The feedback device is in communication with the controller and is configured to produce an audio or video output, or combined audio and visual output, based on impact data produced by the impact sensor upon sensing an impact and processed by the first controller. The controller can be programmed to provide specialized training regimens and/or interactive training programs, such as over a computer network.