I always get hurt the index toe of my right foot when doing my long run, the nail is black and very thick. In my last run I applied a little vaseline, it was better but still the index toe get hurt. How can I protect better that toe. I bought new shoes, one size bigger. My long run is for 18-20k
I saw Anton Krupicka to take of something from his toes when he was running with Kilian Jornet (Kilians' Quest)
Blackened and/or losing toenails is very common among very long distance runners (half marathon and longer). One of the primary causes is the foot being too loose in the shoe, and being rammed into the front of the shoe repeatedly.
Oddly enough, buying shoes one size bigger can lead to worse problems, and still not solve the original problem, as the toe/foot now have even more room to move and slide around, and will promote bad practices such as tying the laces too tight to try and prevent it.
Get proper fitting shoes, and if possible, get a gait analysis done. It is possible that your natural running motion is promoting the smacking of your toe against the front of the shoe, and changing your stride/plant pattern slightly can help alleviate any damage.
