This is not the run of the mill “How long will my running shoes last” question. I know the standard answer, “depending on the shoes and on the runner 300-600miles yadda, yadda, yadda”. I have often heard, read and then passed on to my patients and friends the statement that running shoes will “degrade” with the passage of time. Meaning that if you own your shoes long enough, regardless of how many miles you have run in them, they will lose some of their cushioning/stabilizing/motion controlling properties just with the passage of time.
I was thinking about this last night as I was running in a pair of Asics Gel Racers that I have had for 2 years and they probably have less than 100 miles on them. They felt great, no discernable difference from how the felt 2 years ago.
Also, the back of every running magazine is filled with advertisements for companies selling discontinued running shoes, some from 10+ years ago. Certainly if it is true that running shoes can’t last more than a year in your closet, then after 10 years in a warehouse they should be completely worthless.
So, is this statement that running shoes lose their oomph just with the passage of time a myth that was perpetuated by running shoe companies to get us to replace our shoes several times per year regardless of how much we are running?
UV light, heat and oxidation will all degrade any plastic over time but the degradation is going to be tiny compared to that from running. I used to fix up “vintage” Nike’s for a guy who sold them to Japanese hipsters for $400 a pair. Most of the old waffle sole shoes he had were still good as new. Some of the foams used over the years became really brittle and crumbly. Most glues used in shoes release their bond at about 140F which is achievable in a hot car. This kills a lot of shoes.
As far as I can tell this is a myth – the component that’s likely to degrade over time is the “foam” that’s used to create the midsole. The chemicals that are used to create that foam have varied over time, and still vary from company to company, but they’re certainly more stable compounds than they were 20-30 years ago. Direct sunlight will probably degrade them, but I don’t see a likely scenario where shoes are exposed to direct sunlight and not used.
The other myth that running shoe companies perpetuate is that you should have two pairs of the same shoe, and that you should alternate them to reduce the wear. That’s a crock. You’ll get the same amount of use buying 1 pair, running x miles in it, then buying another pair and running x miles in it. There are two reasons to have two pairs of running shoes: 1)different shoes for different purposes, such as long distance, tempo, or track work, and 2)if you run more than 4 days a week and it’s likely that your shoes may still be soaking wet from yesterday’s run, then having more than one pair does make sense. In that case, alternating them will keep the wear about equal between the two shoes.
Lee Silverman
JackRabbit Sports
Park Slope, Brooklyn
Unless someone gives me really good evidence otherwise, yes, that’s my conclusion. Makes no difference if the shoe sits in the manufacturers warehouse, in the basement of your local running store, or in your closet. It’s in new condition until you run on it. That said, if you just let it sit there for a year or two it might get a little stiff. And if you expose it to significant temperature variations you might decrease the life of the shoe a bit.
Lee Silverman
JackRabbit Sports
Park Slope, Brooklyn
That’s pretty much what I thought. I guess I had never really gave it that much thought before, just went on what I read or was told. Now that I have pondered it, it just doesn’t make sense that they would degrade significantly over time without use.