73k this week. Sunny Sunday so opted for a 32k long run. 10th Feb 10k tempo 4.08/km 11th Feb 11k lap of Richmond Park 12th Feb 10k 4.37/km 15th Feb 10k 5x1k intervals average 3.50/k with 30 second rolling recovery 16th Feb 32k 2h39m 4.57/km - all was going well until the final 7k...poor pacing.
So when do you change shoes?
Changing shoes is like a haircuts for me. It something you should do reasonably regularly but there's always an uncomfortable transition period once it's done. With a haircut it's itchy neck from the hair that finds it's way down your shirt and with new shoes it's the breaking in period that can limit the amount of miles you can run, increase pressure on the feet as they adjust to the new shoe and pick up the occasional blister when the new rough material rubs on it.
As a result, I don't change my shoes every 300-500 miles as seems to be the common suggestion. I have been unable to find any research that points to the need to change shoes that often. 6-10 weeks of wear does not sound like much to me. I admit my current favourite shoes were probably past there best before date a few months ago but they were very comfortable and seemed to provide me with sufficient support and the soles were intact.
Unfortunately when I upgraded to the recent model of the same shoe it was on a 16.5 mile day which was a bit too much for a new shoe and was left with an aching foot where the laces rubbed for a few days.
So whilst there does not seem to be much research as to why you change your shoes the suggestion seem to depend on firstly your weight and secondly your style of running as to how you quickly you break down the shoe structure. Obviously the material makes a difference too, lighter race shoes tend to be constructed of a less durable material so will wear quicker.
Anecdotal evidence suggests that rotating 2 pairs will prolong the life of the shoes as there is more time between the runs to allow the compression to recover.
I personally run with 3 different styles of shoe. One is dependent on terrain, so is a bit more durable. One is my race shoe which I will do most of my runs in and the other is my old race shoe which I will use occasionally just to give my other shoe a rest.