It a difficult question to answer really, and i suppose can only be answered as 'as long as you find them comfortable'. How you done much running in them before, and have you ever got blisters running in them?
I wouldnt worry too much about buying a really decent pair for PRMC, but if you are wanting a decent pair then i would go to a shop. I did a ultra marathon last year and had no idea about the effects different shoes have. there are loads - arch support, front, back support, bubbles, gel bloody loads! If they're not giving you any grief then i'd stick to the silver shadows, but if your wanting a pair shop about abit!
Best of luck!
Don't even bother reading any post here other than this one. Go and get your gait checked, they will advise you on a pair of runningvshoes to suit your style of runing which is highly important. Don't buy any running shoes without comparing them to your running style and trying them on and running in them first!
Anyone who tells you differently is wrong, your feet are the most crucial part of your body to keep clean and injury free!
A good pair of running shoes are vital in my opinion. I had a pair of asics too, recently got some new ones in the Nike Air variety. I prefer them to my asics up to now but then that could be because my asics were a size 11 or 12 and I tried on a size 10 with the nike's and they fit perfectly!
agree with Ash on this one, i only discovered i had a proper running store in my city centre AFTER i spent £60 on a pair on ascis online! *text deleted*
i called in to have a nosey and they have everything, they told me to bring along my old running shoes, and they would put me on the GAIT analysis machine (basically a treadmill with some sort of computer software hooked up)
i havent got it done yet, as i have just forked out £60 for these ascis, but if i hada known sooner it woulda saved me alot money, and Possible injury in the long run