Mats

Even if you remain fully clothed, you probably place your hands on your yoga mat or press your cheek or forehead against it during resting positions. This is a breeding ground for MRSA or methicillin-resistant staphylococcus aureus, a bacterium responsible for several difficult-to-treat infections in humans. It’s also called oxacillin-resistant staphylococcus aureus. Your best bet is investing in your own mat, and wiping that down when you get home as bacteria could be on the gym floor.

Towels

Gym towels are usually cleaned and even sterilized, but you can invite bacteria and viruses onto them depending on how you use them. Bring two towels to the gym: one to wipe down your equipment, and one for your face and body. Never use the same towel you used on equipment on your body. A dirty towel can quickly transfer germs from another person onto you, or even from you onto your own body (if you sweat or spit into the towel).

The sauna

That relaxing, rewarding sauna isn’t as safe as it seems. Always sit on a towel in the sauna or steam room so there’s something between your skin and the seat. Sauna and steam room seats often carry candida fugus, or tinea – a fungal infection of the skin.

Locker room floor

Breezing around on tippytoes doesn’t protect you: if there are bacteria on the floor, your bare skin can quickly pick up a fungal infection or even warts.

Your workout clothes

Be sure to change into a new pair of underwear as soon as possible after exercising. Excessive moisture can cause irritation or even infection, and is often the cause of urinary tract infections. But infection isn’t the only risk: hanging out in wet workout clothes can actually cause butt acne. If this does happen, use anti-bacterial, antimicrobial wash to treat the affected areas.

Your gym bag

This is a tragically overlooked bacteria breeding ground. You probably carry your moist, dirty gym clothes in this bag several times a week without cleaning out the inside of it. The bacteria left in there from your dirty clothes can transfer onto the clean ones you plan on wearing, and onto your body. Be sure to wash the bag at least once a week and never re-wear workout clothes without washing them first.

Water bottle

When you flip open the sports top of your water bottle, you instantly transfer germs from your hands to your bottle, and eventually your mouth. Always wash your hands thoroughly before touching your water bottle. You also introduce germs into your bottle every time you refill it through the air stream. Be sure to wash out your water bottle after each use. If possible, fill it up as far away from the locker room as possible.

Workout classes

When you’re exercising, you’re taking deep, prolonged breaths, making it easier for you to inhale airborne bacteria. So when you’re taking a fitness class, you’re doing that in close proximity to dozens of sweaty bodies. Try to keep at least six feet between yourself and anyone who is coughing or might be contagious in a workout class.

The remote control

If your workout time is also when you catch up on “The Food Network,” then you’re probably flipping the channel on those built-in remotes on your machine. But these can carry everything from MRSA and E. coli (a common foodborne illness that can cause serious infection) to the flu and even norovirus – aka stomach flu or viral gastroenteritis. If you touch the remote, be extra careful not to touch your face until you’ve washed your hands. If you can, just ask a staff member with the main remote to change the channel for you.

Bathroom soap dispenser

Yes it’s ironic and even evil: the device meant to protect you against germs can be passing them along to you. Soap dispensers can carry some nasty bacteria, like members of the genus pseudomonas, an organism that can attack various parts of your body. Be wary of soap that’s leaked out of the dispenser. A biofilm of bacteria can grow on alcohol-based substances.