Choose carefully. Pick a mat from the bottom of the pile before class starts. The mats at the bottom are the gym mats least likely to have been used by the previous class. Choose the mat that is the least moist.
Clean the mat. Carry a small towel and spray bottle with a solution of one part vinegar to three parts water. Spray the towel and wipe the surface area of the mat. Do not spray the mat because it will make the mat too moist. Be sure to wipe the mat well.
Sanitize the mat. Carry a small container of Lysol, and spray the surface of the mat lightly but thoroughly. You may need to take the mat outside of the main room to do this.
Let dry. If the class does not require you using the mat immediately, try to allow the mat to dry for the majority of the class period until it is needed.
Use a towel. Put a clean towel that you bring from home down on the mat before beginning your activity. This will help you to avoid contamination from any areas that were not thoroughly sanitized.
Consult the staff. Ask gym staff how often they sanitize the gym mats. Be sure they clean them nightly to avoid any bacteria or germ buildup. You can clean the gym mat to ensure it is safe to use, but it is up to the gym staff to ensure the equipment is sterile for their guests. Be sure to talk to the management at your gym if you feel the gym equipment is not being cleaned properly.