White and crusty after a run?

So a while ago I noticed that my forehead was a little white after playing racquetball on a Saturday morning.  I didn't think much about it at the time.  Some time passed and it happened again.  So I started doing some reading and wondering if it was something to worry about or not.  

I'm not worried about it, but now I'm aware of it.  Here's an article at Runner's World that talks about salt intake.