Wearing polyester clothes makes the sweat smell more obvious after exercise. A new study says that this may be because polyester materials are more suitable for the growth of some bacteria.

Researchers from Ghent University in Belgium and other institutions reported in the new issue of Applied and Environmental Microbiology that some T-shirts worn by healthy volunteers during exercise were collected and left for 28 hours. By contrast, the sweat smell on polyester clothes is really bigger than that on cotton clothes.

Further analysis shows that some bacteria on polyester clothes grow faster, such as a micrococcus that can decompose long-chain fatty acids. Long-chain fatty acids in sweat are not volatile, but after bacteria break them down into smaller volatile compounds, the smell of sweat is more likely to appear on clothes.

As for why polyester materials are more suitable for the growth of these bacteria, researchers continue to experiment. One view is that compared with the fibers on cotton-padded jacket, polyester fibers have poor water absorption, and the water retained between fibers promotes the growth of bacteria.