Downhill mountain biking is a challenging sport. You need to warm up and practice well before the race. The main problems that you might face are injuries, so if you escape with just cuts on your hands and knees, it is okay. You may also face more severe consequences like fracturing your hand or leg or even your jaw. When you go mountain biking you need to be well stacked with your medical kit, knee pads, elbow pads, helmets and goggles to avoid any serious damage. Be safe and follow your instructor's instructions well. Also make sure that the bike is fitted out well and does not have any loose parts.