A "trail runner" refers to someone who enjoys running specifically on trails or in off-road environments, rather than on paved roads or tracks. Full definition
They really do fill a niche between a dedicated trail runner and a road running shoe without sacrificing quality or performance for either activity. (businessinsider.com)
Being a regular trail runner and someone who tends towards the clumsy side, it just happens. (bellymindsoul.com)
Devon About Blog Trail runners and organisers of the Wild Night Run race series in the South West. (blog.feedspot.com)