Incidentally, you should not put your running shoes in the washing machine, nor use very hot water to clean them. The hot water damages the shoe, especially the mid-sole, and leads to distortion in the shape of the shoe. For the same reason, you should avoid drying wet shoes on a very hot radiator.
You sometimes see inexperienced runners looking at the bottom of their running shoes to see if it needs replacing, for example by seeing whether it has much 'tread' left. This is a mistake: the main determinant of the longevity of a shoe is not the wear to the outer sole; it is the compression of the mid-sole, which is the spongy layer between the outer sole and your feet.
The material that is usually used to make mid-soles is light and absorbs shock well, but it gradually compacts as it is used, which reduces its shock absorbency and gradually distorts the shoe.
