Running is the most dangerous sport. That sounds like a ridiculous statement, but when you consider that 80% of runner are injured every year, it sounds more like an epidemic than a sport.
It doesn't need to be that way, though. Human beings are built to run, but our modern lifestyle has set us up for failure. Between our high-heeled shoes, commuter lifestyle and sub-par nutrition, it is hard to handle any sort of running volume without complications.