The dirtiest, most bacteria-infested places in the gym

Cardio equipment is particularly loaded with germs. In 2017, a company that reviews fitness equipment, called Fit Rated, conducted an investigation where it analyzed bacteria samples from 27 pieces of equipment across three different gyms. Fit Rated found the largest number of germs on treadmills, where there was 1,333,432 colony forming units (CFU) per square inch. This is 74 times more bacteria than is found on a bathroom sink faucet, according to the report.

The most prevalent bacteria were gram-positive cocci, a category that can cause skin infections, pneumonia, and sepsis, among other infections.

Another study published in 2014 in the International Journal of Environmental Research and Public Health found that treadmills also harbor bacillaceae, another type of gram-positive bacteria that can cause infections like meningitis.

The Fit Rated experiment found stationary bikes to be almost as germy as the treadmill, with 1,333,418 CFU per square inch. Like the treadmill, the most prevalent bacteria was gram-positive cocci.

The elliptical also carries a lot of germs. According to the study in the Journal of Environmental Research, the most prominent type of bacteria found on ellipticals is staphylococcus, which represented 52.7% of the bacterial load. This kind of bacteria is responsible for staph infections, which lead to skin abscesses. Enterobacter was also prominent, which can cause respiratory infections and urinary tract infections.

A 2019 study published in BMC Infectious Diseases, analyzed bacteria samples from 288 surfaces across 16 fitness facilities in Northeast Ohio and found that weight balls were the germiest surface. 62.5% of weight ball samples tested positive for staph.

According to Mark Dalman PhD, associate professor at Kent State University and leader of the study, staph bacteria was the focus of this study since MRSA -—staph bacteria that is resistant to antibiotics — tends to be found in high contact businesses such as athletic centers and gyms.

The Fit Rated study found free weights to harbor high amounts of bacteria, with 1,158,381 CFU. That's 362 times more germs than a toilet seat, according to Fit Rated.

But instead of gram-positive bacteria like that found on treadmills and ellipticals, researchers found gram-negative rods. Certain strains of gram-negative bacteria can cause pneumonia, skin infections, and blood infections.

Dalman's 2019 study in BMC Infectious Diseases also found weight plates and cable-driven curl bars to be high in staphylococcus germs, meaning that weight-related equipment in general is very germy.

It's not just exercise equipment. The 2019 study published in BMC Infectious Diseases found gym water fountains to be loaded with germs, too. The study concluded that there was more staphylococcus present on the water fountain than bathroom doors and bathroom sink handles. Dalman says this could be related to the fact that there are far more patrons than water fountains, so there's higher contact. "One or two central water fountains with potentially 50 or more people who aren't washing their hands before taking a swig of water is an issue," says Dalman.

Most strains of bacteria are harmless. However, there are a few that can cause illness and disease. It's nearly impossible to tell if the strains on your treadmill or gym weights are pathogenic, or not. So, it's better to be safe than sorry. Moreover, it comes down to the facility and the individual's hygiene practices, says Dalman.

Gym-goers are urged to wipe down whatever equipment they used after they are done exercising. Most gyms will provide wipes or disinfecting sprays to decontaminate surfaces. But you should still wipe down any equipment before you use it, just in case the person before you did not. For example, a survey of 1,004 gym-goers found that 34.9% of men and 24.5% of women admit to not wiping down weights and weight machines after using them.

If you're going to be sitting or lying on a surface like a weight bench or yoga mat, you should put a towel down to protect yourself from germs on those surfaces. And if you're nervous about the cleanliness of the gym towels, bring your own with you to the gym.

Dalman also says that you should cover any cuts, abrasions, or skin openings when you hit the gym in order to protect yourself from infections.

Other tips include general advice you already use to stay healthy. Wash your hands for 20 seconds with soap and water before and after working out. Avoid touching your face, especially your eyes, nose, and mouth while you work out.