Did you know that sweat doesn’t smell? That nasty scent actually comes from bacteria. The same bacteria that makes your armpits smell (extra when you sweat) can also make your running shoes smell. This is because our feet are covered with sweat glands, so all that sweat and bacteria get trapped in our running shoes and socks.
The Cause Of The Smell
“Just as with all other organisms, bacteria need fluid to thrive, and your foot sweat does that job perfectly,” explains Sara Landvik, who works at Novozymes and is an expert in bacteria and other microorganisms.
Our skin is covered with bacteria, including staphylococci, micrococci and corynebacterium—and that’s quite normal. When your feet sweat, corynebacterium and micrococci break down the sweat into a fatty acid called isovaleric acid, which causes the smell in your running shoes.
But bacteria can do much more than make your shoes smell—they can do good things, too. They are extremely important in ecosystems, where they are crucial to maintaining life and breaking down materials such as plants. Today bacteria are used as a natural fertilizer in agriculture, for the production of flowers, vegetables and crops such as soy. Microbial solutions protect crops against diseases and help plants grow better.
Three Steps To Fresher Running Shoes
Freeze: Put your shoes in the freezer to kill the bacteria, as they cannot endure cold temperatures.
Dry: Bacteria and microorganisms thrive in damp conditions, so keep your shoes dry, for example, by stuffing them with newspaper after a run.
Neutralize: Because the smell in your shoes comes from isovaleric acid, you can neutralize it with an alkaline compound like baking soda. Sprinkle half to a whole tablespoon of plain baking soda into each shoe and leave them overnight.