This present invention concerns an impact detection device, as well as a system that includes such a device, and is employed particularly in electronic training systems for a combat sport, or for simulation of such a combat sport, such as boxing, karate, kendo, or fencing in particular, or more generally in a sport in which the user creates an impact by striking an adversary or a support, directly or by means of an object that is liable to transmit the impact. This device includes a sensor that is designed to detect an impact and its intensity, which is mounted on a printed circuit, together with indicating means that are designed to be activated when the detector detects an impact and/or in order to indicate to a user that he must generate an impact, and which is imbedded in a protective covering so that it is located near the surface of this embedding material. The indicating means are mounted directly on the printed circuit, so that the embedding material also covers the printed circuit and the sensor.