You're probably not cleaning your yoga mat as often as you should be using mat sprays, as recommended by professionals.

You're doing yourself a disservice if the last time you cleaned your yoga mat was, well, never. If you don't frequently wipe off your yoga mat after your at-home or studio session, it can become a breeding ground for odor-causing bacteria (due to the excess moisture left behind). As you exercise, they absorb perspiration, grime, and other particles from your body. Cleaning your yoga mat, on the other hand, isn't always as straightforward as tossing it in the washing or spritzing it with your favorite disinfectant.
To begin with, not all yoga mats are cleanable in the same way. Open-cell mats, such as polyurethane foam mats, have a porous structure that helps them to absorb perspiration and moisture more effectively. While this design is ideal for hot yoga, it allows bacteria to thrive within and cause odors that are difficult to eliminate with wipes or other treatments. Closed-cell mats, on the other hand, are not porous or absorbent, making their surfaces easier to clean.
According to Jessica Gershman, yoga instructor and CEO and founder of The Zen Mommy, cleaning your mat at least once a week is the golden rule, regardless of what mat you use for warrior pose and downward dog. However, if you have a more strenuous yoga practice, once a week may not be enough. "...If you practice every day or in a hot yoga style, I recommend using an all-natural water-based cleanser to clean your yoga mat more frequently." "I usually strive to use cleaners with non-toxic organic chemicals—especially if my face and body will be in close contact with the surface like a yoga mat,"