Picking out the proper running shoe is one of the most important decisions you'll make in marathon preparation. All of your miles will not make a difference if you come down with a bad blister or rub spot on race day.
You should have 2 pairs of shoes- one for training, and one that you'll be doing the race in. While there are no hard and fast rules, the general consensus is that heavier runners (for arguments sake we will use 170 lbs as a threshold) cannot afford to sacrifice cushioning over weight.
Regardless, make sure to do 3-4 runs longer than 2 hours in the shoes you will be racing in, and that's it. You'll want maximum support without having to worry about fit.
According to runnersworld.com, you can run one second per mile faster for every ounce lighter your shoes are. In shorter distances, you can get away with wearing very little support, but over 26 miles the increased trauma from lack of cushioning may not be worth it.
Lighter, faster, efficient runners can probably get away with lighter weight shoes, but you should practice a few race simulation long runs in them to be sure.
I remember reading years ago about how Frank Shorter was up the night before his Olympic victory in Munich shaving extra rubber off of his shoes anywhere he could to save weight.
Tips for buying shoes:
- wear your running socks
- bring inserts if you use them
- make sure the fit is good- one finger width of space at the toe, no sliding in the heel, and no potential "hot" spots
How to buy the right running shoe- some good links here. When in doubt, seek out expert advice.
NEVER RUN A MARATHON IN BRAND NEW SHOES
(c) Dave Elger 2008 All rights reserved