Don’t machine-wash dirty running shoes
I have a 1970’s memory of my mom using the washing machine to clean my shoes. (Don’t ask me what kind of shoes they were, I didn’t know if I was wearing dirty running shoes or basketball shoes or tennis shoes–as long as they weren’t the dreaded bobo shoes!) They didn’t fit exactly like before but I was too young to dwell on that.
This is what happens when you wash dirty running shoes
I also remember the only time that I washed my dirty running shoes. I was a young adult. Into the washing machine went a pair of good shoes and out came a twisted and mangled mess. Shocked, I threw them in the dryer thinking, if I can call it thinking, that the dryer would straighten them out. Within a few minutes, the smell was a signal that the shoes were in even worse shape.
This is why it happens
Technical running shoes are constructed to withstand moisture from the inside and the outside. Up to a pint of water can collect inside of them and it is common for runners to wear them on rainy or wet days.
But dirty running shoes were not designed for a washing machine’s environment. They’re not supposed to be completely submerged in chlorinated water–with detergent–for up to 60 minutes. These days, a sneaker’s many parts are all glued together. Water, chlorine, and detergents act like solvents—they dissolve adhesives. This is very much the case with detergents, whose molecules act to reduce the force of adhesives.
The washing machine, therefore, is one of the worst imaginable environments to put running shoes in.
Notwithstanding the aforementioned, technical running shoes are very well-designed, well-researched, and well-constructed. They are able to withstand the tremendous forces of a run and still bounce back by the next day. They are probably the most researched and developed athletic shoes in the world.