How often do you replace running shoes?

I just got new running shoes this week (same kind as my old ones) and by the time I finish breaking in the new ones, the old ones will have around 300 miles.  All of a sudden the shoes just didn't feel as comfy as they used to, so I replaced them.  The old ones will be worn for the New Year's resolution 5k run, as the finish is a jump, fully clothed and shod, into freezing Lake Washington.  I don't want my new shoes to go through that.  I will also use my old shoes as my trail running shoes to keep the new ones clean. I wore much older (never really comfy) running shoes for my last trail run and got the worst blisters that lasted for weeks.  Lesson learned.

I don't know if you need to replace shoes earlier if you are heavier.  I do know my husband, who is a big guy, wears through his regular shoes about twice as fast as I do.  I say listen to your body, it will tell you.  If you are someone who changes their oil in the car the minute it hits 3000 miles then you will probably want to change shoes at 300.  Otherwise, it's your call.  Some people talk about having two pairs and rotating them.

Yeah, the numbers vary wildly, but I hear 300-600. I have definitely noticed that when I was heavier, it was much closer to 200-250, and now (40 lbs lighter) it's more like 400.

RUNNING SHOE TIPS:

1. write the date you got them in Sharpie on the side, and log ALL miles religiously (do you walk in them? Go to the store?). That way, you know for sure when you're getting to several hundred miles on them.

2. Better yet, if you like the shoes, get a second pair while that model is still available.

3. When you've put a couple hundred miles on the first pair, plan a run now and then when you can be home (or at your car) with just a little bit left to go (say, cool-down). Swap the pairs and do the final part of the run in the second pair. You'll break them in easier, AND you will feel without a doubt when the old ones just aren't giving you the same support the new ones are--then it's time to chuck 'em.

I find they last me between 250 and 300.  I start to get twinges/nags etc. in my knee and lower legs when they get in that range especially on the long runs.  I log every mile and dont do anything but run in my shoes.  No trips to the store, just running.  I assume that the heavier you are the lower the life expectancy of a shoe is.  I tend to run right around 200# for what its worth.   

-Mark 

I've been told between 250 - 300 miles (depending on the sales person) on average, light folks will get longer life out of their shoes than guys my size (245). I've got almost 250 miles on these shoes and I'm sure they need replacement...knees, ankles and feet get REAL angery after my longer runs. I think thats a darn good sign.