The problems arising from the increase number of sporting events held in the natural environment are evident, especially Trail Running events in Protected Natural Areas (e.g., post event environmental damage, consolidation of these Protected Natural Areas as a training arena, widespread growth). Hence, there is a need to provide insigts to this phenomenon. This work has three main objectives: 1) to identify the number of events, its evolution and territorial distribution of Trail running in Spain, 2) to study the incidence of these events on the different Protected Natural Areas belonging to Natural 2000, and 3) to analyze the main characteristics of the incidence on the Protected Natural Areas. Systematizing and georeferencing the 1901 events registered on the website runedia.com, in 2015, we identified a predominance of foot modality, with an 8% of yearly increase rate, and a very heterogeneous distribution by regions. With a margin of error of 5%, we were able to establish a global incidence rate of around 86%. The month, the number of tracks and the intra region pressure, were some of the few characteristics that we could analyze in relation to the 1624 Trail Running events which took place in some of the Natura 2000 areas.