Differences of dri-fit & cotton

From what is seen on the streets and in the races, perhaps more than 90% of people wear “special” running shirts: fast-drying, super-ventilated, moisture-reducing and almost even with built-in air conditioning, as suggested by recent publicity. And it’s okay; the truth is that Dri Fit shirts are tasty but are they better than plain cotton?

Two recent investigations tested the benefits of exercise with Dri Fit type shirts, compared to standard 100% cotton shirts. Dri Fit is a Nike material, containing polyester, cotton and spandex. But it is not the only brand that has fabrics that claim to optimise sports performance; each brand has its own distinct name: Clima cool, Heat gear, Play dry, etc. Not to bother with details, we will generally talk about Dri Fit fabrics, whose main component is polyester.

Although it is widely accepted and used by sportsmen, none of the research has shown that running with Dri Fit shirts has a positive effect on performance. The first study, from 2013, put eight well-trained men to run with different types of polyester, as well as cotton shirt, in 32 degree Celsius (rather warm) environment. The test consisted of running 30 minutes at a relatively comfortable pace (70% of maximal oxygen consumption), followed by an increase in intensity to exhaustion.

Moisture levels in the chest and back were lower when they wore polyester shirts, and the feeling of heat and sweating were also lower compared to when they wore the cotton shirt. Athletes’ body temperature was also lower when using polyester, but only during recovery. While running there was no difference in temperature. There were also no differences in heart rate, oxygen consumption, lactate levels, ventilation and heat perception. But most important of all: there was no difference in performance.

That is, wearing Dri Fit shirts in a hot environment did not make any difference in performance. Based on this, it could well run Sol and Arena with his old gardening shirt and it would go as well (or just as bad, I do not know) if he used his shirt with aerospace technology that cost him $ 100.

Another study compared the performance of six men and six women while wearing white cotton shirt, black cotton shirt, white polyester shirt and black polyester shirt. They put them to run 10km with each shirt and made several measurements. They saw no difference in athletes’ pace, heart rate, or differences in rectal temperature or skin temperature, regardless of the colour or material they used.

It was only found that the black cotton shirt had a higher temperature than the others, but this did not affect the performance of the participants. In short, neither the colour of the shirt nor the type of material influenced performance.

Based on these two investigations, one could say that the advantages of Dri Fit shirts are limited to a theme of perception and comfort (not in all cases), rather than to a performance theme.