I bought these shoes to replace a pair of NB that I totally wore out.  The first pair of NB that I had took me all over Disney World, the western United States and Europe.  Absolutely loved them.  These were a higher number, therefore, I figured they would at least last as long as the other ones did.  I'm a walker not a runner, but the fact that these are a fitness conditioning shoe I knew they would work for me.  They needed no breaking in as they were very comfortable from day one.  These should work for me perfectly.