Unlike long-distance running on flat surfaces, trail running is running on a variety of trails, from roads covered with sand, rocks and mud to grass, streams and slopes. To get through some of the tracks, runners even have to squeeze through dense trees or run through caves. So, to help keep you safe on challenging trails, we've compiled a list of five essential trail running accessories below. The type of accessories you need will depend on the difficulty of the run. If you're new to trail running, you should avoid roads with lots of slopes and choose routes of lower difficulty, with grass, sand or small gravel surfaces, such as stages 5-6 on the Palace run the famous MacLehose in Hong Kong (note the distance shouldn't be too long either).