At the time of physical activity, is it better to use cotton or polyester? If you don’t like the smell your clothes give off after a workout, the correct answer is cotton. The conclusion has a scientific basis: a study published in revista applied and environmental microbiology I previously investigated why synthetic clothes smell worse than cotton after a fitness session.

It all started with volunteers who were willing to smell two T-shirts, one made of cotton and one made of polyester, that healthy people would wear during an hour-long rotation exercise.

The analysis was performed 28 hours after the end of the physical exercise, to allow time for the bacteria to break down the fatty acids present in sweat into smaller air molecules. This is what makes you feel bad.

The volunteers had no doubts: polyester shirts smelled more badly than those made of cotton.

Then the researchers looked for explanations. Looking at the fabric under a microscope, they found that bacteria called micrococcus reproduce better on polyester, possibly because cotton doesn’t absorb much moisture.

The result is that bacteria are better stored among the synthetic fibres.

So, here is a tip for lovers of physical activity: it is preferable to wear cotton clothes during training.