After a workout, many people don't think twice about putting their dirty, sweaty clothes back in their gym bag. But in doing so, you may be exposing yourself to hazardous bacteria.

Inside Edition went to Gravity Fitness in New York City, where we linked up with model Alissa Bourne as she was wrapping up a vigorous workout. As always, she put her sweaty clothes back in her gym bag after getting changed. 

Asked about the last time she cleaned the bag, Bourne told Inside Edition Chief Investigative Correspondent Lisa Guerrero that she doesn’t think she's ever washed it in the two years she's owned it.

Guerrero took a swab and swiped it across the inside of the bag. She repeated the process with 15 more people and their bags. Then, all the swabs were sent to a lab to be tested for bacteria and fungi.

While Bourne’s test came back pretty clean, the results left others feeling queasy.

Business student Colin Lee, who agreed to have his bag swiped, was shocked when he learned he was carrying around two types of bacteria, one of them E. coli.  

Small business owner Cristina Laverde's results grossed her out. 

“We found Staph aureus in your gym bag," Guerrero said. "Cristina, Staph aureus could cause skin infections, bone infections and joint infections."

“Oh my God, that's not good, that's doesn't sound good, oh my God,” a shocked Laverde said. 

So what can you do to keep your gym bag clean?

Take a plastic bag along for your dirty clothes — some gyms stock them for members — and throw your gym bag in the wash every once in a while to keep those germs away.

RELATED STORIES

Investigation Explores Alarming Trend of GPS Devices Attached to Cars of Unsuspecting Women

Does the Purple Mattress Live Up to the Hype? Investigation Puts It to the Test

Beware: Tow Truck Drivers Could Be Lurking Just Around the Corner, Waiting to Haul Your Car Away