Do running shoes have a shelf life? If they are new, in the box, sheltered from UV rays and swings in temperature, do they just sit waiting for the day they make their debut, or do they ‘go bad’ or expire somehow? I have heard 1 year in the past, but can’t confirm…
Can’t answer your question, but I usually buy 3-5 pairs at a time and I’ve never noticed any degradation by the time I use them. Sometimes I’m buying last years model, which means they might be a year old when I buy them and then on pair might sit in my garage for 8-10 months before I wear them.
Plasticizer migration (the same reason you shouldn’t drink commercially bottled water or anything else that comes in plastic) will eventually cause the materials in the soles to cross link and become stiff and/or brittle, but I wouldn’t know what that would mean in terms of actual shelf life. Again, I’ve used shoes that were potentiall two years old and never noticed any compromise in function.
I’ve noticed that when I buy a pair of shoes and store them, that they don’t last as long when I start using them as the ones I started wearing right away. Usually it’s the EVA midsole that tends to compress more quickly.
a friend who works for nike said around 2 years before the rubber starts to degrade or depends on what your mileage is he said. i did write them an email about a racing flat i only used for racing which broke during a race-- the whole sole tore off and the rubber was crumbling like sponge cake. it was more than 2 years but looked perfect, bacteria eats the rubber he said in time. no direct sunlight and always aerate them he said
Can only give you 2nd hand info from the girl who works at my local running store: shoes do age when sitting in a box, even when sheltered from light, moisture, high temps etc because the material used for cushioning (foam?) compacts over time, thus diminishing its functionality. Her rule-of-thumb advice was to not let new shoes sit around unused for more than three month, assuming that they haven’t been sitting on the shelf in the store or at a warehouse for more than their “usual” time (and I don’t know how much that is) as could be the case with shoes that aren’t that popular…