Scientists reveal why some fabrics trap in the sweat smell – and how to get rid of the stench

Workout clothes are designed with durable materials to withstand the most challenging exercises, but these fabrics also trap in smells that linger after washing.

A new TikTok video revealed your body odor soaks into certain textiles like polyester because they are hydrophobic, meaning they are oil-based and attract such substances.

Polyester, spandex and nylon, widely used to design clothes, repel moisture and dry faster, but little notches in these fabrics soak up sweat molecules.

However, experts have shared cleaning tips to banish the stench, such as pre-soaking them in vinegar and avoiding tossing them in a hamper.

Most avid gymgoers notice their workout clothes do not smell clean even after being washed

Most gym clothes are designed with polyester, spandex and nylon because they are cheap, durable, lightweight and fast drying – all the things avid gymgoers look for when choosing the right gear.

If you are unsure what your clothes are made of, the collar tag usually answers that. 

And the three are usually combined to make stretchy, durable designs.

Scientists at the University of Alberta found odorants-smelly compounds more attracted to polyester than other fabrics like cotton and do not completely wash out.

Mukhtar Abdul-Bari, who conducted research in 2021 for his master’s degree in textile and apparel science, said in a statement: ‘We found that polyester is not easily releasing those sweaty-smelling compounds, and repeated wearing puts more of them into the fiber, so over time there’s this buildup of odor.’

Polyester is a non-polar fiber meaning it repels water-which is why it dries quickly, but that also means it naturally attracts oil from our skin, which can lead to body odor, Abdul-Bari said. 

Nylon is a synthetic polymer first developed in the 1930s to replace silk. 

A 2018 study conducted by Abdul-Bari and colleagues asked eight participants to wear shirts made of polyester and shirts made of nylon to asses which trapped more odor.

The reason is most workout gear is designed with polyester, nylon and spandex, which trap odors. These synthetic fabrics have tiny notches that collect bacteria and oil

‘Overall, no differences were found in odor intensity between nylon and polyester,’ reads the study published in SAGE journals.

‘Any differences found between the two fabrics were likely dependent on the individual who wore the fabric.’

The team did find the odor reduction rate was higher with nylon.

And spandex usually smells because of bacteria in body oils because it is a non-absorbent material. 

How to get rid of the stench

Skip the hamper and let your gym clothes air dry, but first, turn them inside out.

Leanne Stapf, chief operating officer at The Cleaning Authority, told NBC that the bacteria and oil are more concentrated on the inside of close and the smell can escape by turning them inside out.

‘Bacteria feed off the darkness, and heat can also magnify the smell from residual bacteria, so you really should avoid tossing gym clothes into a hamper,’ she explained. 

And placing dirty gym clothes in a hamper does not let the light or airflow in.

Pre-soaking your workout gear in a mixture of vinegar and water for 30 minutes will also rid them of the smell.

CleanMySpace suggests a solution that is one part vinegar and five parts water.

And washing them in hot water after every wear will also help rid them of body odor.