I started running long distance, my toe got bruised (under my toe nail) how do i prevent this from happening?

Uhh it depends on how you bruised it. If you smashed it or stubbed it, running on it will make the healing process slower. Ice it a lot. You'll get over it fast. if it is getting bruised from running itself, I'm not sure what to tell you. I would say that it may be trying to push up through your shoe right before your foot hits the ground. When it does this, it's probably hitting the brim of the top of your shoe. Or it could be something as simple as your shoe it too loose or small. RUN AND TELL THAT, HOMEBOI