Running is very popular among professional and amateur sportsmen. To achieve good training results it is necessary to evaluate training effectiveness. Running dynamics, as indicator for effectiveness measure, typically computed from heart rate and trajectory data. Available on market non-expensive devices do not provide enough accuracy and may not include all necessary sensors. In this paper, we discuss the prototype of the non-expensive system for computing running dynamics. The accurate and smooth trajectory is crucial to compute that characteristics with enough accuracy. In order to achieve it the new method of integration GSNS and IMU measurements is used.