There are many extreme sports out there that could lead to the participant's death or serious injury, most sports vary in the ways that you can violently break any one of your limbs. One of these sports is mountain biking which brings significant risks for the thrill of going right next to the edge. However, one needs to remember that this significant danger can easily end in death or permanent disfigurement, nobody should ever go mountain biking without ample preparation. This includes at least one form of communication with emergency services, a method for navigation, the proper safety gear and some supplies for the worst case scenario. Having all of the above listed things is simple enough you just need to pack them up put them on your back and forget about them till you need them, except for the safety gear.
Navigation and communication are also fairly important when it comes to mountain biking, if you don't have a form of communication with you then you could end up stranded in the middle of nowhere with nobody to contact for help. And having a phone with you could save your life, as for navigation you could use a bike GPS which attaches to your bike's handlebars. The bike GPS could potentially save your life if you get lost during the biking trip. Having at least two to three people with you would also go a long way for staying safe while on a trail. The number of ways that you can prepare for emergencies are numerous, you could have a vehicle with you for extreme situations. A radio would give you more range giving you more ground that you can cover while also staying in contact range of the emergency services in that area.