<human>: I am currently training for a marathon on 1/9/11.  Today, I ran 20 miles for the second time.  The run was fine overall, except around mile 15 my feet started to hurt real bad.  I recently got fitted for shoes (Brooks adrenaline) at Fleet Feet, and my shoes are a big upgrade from the $40 nikes I bought at Academy I had been running in previously.  I have ran in these shoes for the majority of my training, and I have never had any problems other than my feet hurting after doing long runs over 14 miles.  Has anyone else had this problem? Is there something I can do to make my feet stop hurting/not hurt as bad? It's really frustrating because other than my feet hurting, the rest of my body feels great and like I could keep running another 10 miles or so.  I have asked for five fingers for Christmas, and I think that will help.  However, my marathon is just a little over a month away, so it is too late to re-train in five fingers.  

Other information that may or may not be relevant:  I'm female, 5'1", 110lbs, around 12% body fat.  In addition to running, I  strength train twice a week, do yoga, swim, and ride my bike as my primary mode of transportation.  I have a short stride when I run and I do not heel strike. I use non-cotton running socks and I have never had problems with blisters or any other issues or injuries.  My feet just hurt.  Bad.

Give me the gist of the text in a nutshell
<bot>: My feet hurt after long runs.  I have been fitted for shoes. It's too late for five fingers at this point.  Please suggest anything that might make my feet not hurt as bad.