The paper shows the design of an athlete performance measurement system for combat sports, which are still characterized by traditional training methods that give the athletes rules to reach effective shots, but without any objective measure. This work aims at a new instrumentation to measure the effectiveness of athletes' training, their moves, their shots, with lower cost than expensive devices available at state of art, whose measures are hard to correlate with useful human parameters. To serve also the market of non-professional athletes a cheap measuring system, based on accelerometers and strain gauges, operating in real time, has been developed and experimentally tested in real-world scenarios. It is organized as a distributed network of three node types: 2 battery-powered wireless sensing nodes to be worn by the athletes and 1 master node managing signal acquisition, processing for statistics, visualization either in real-time during a combat training session or off-line for post-training performance analysis.