There are two sides to the debate of cotton versus synthetic clothing for me. One, which I will address in this post, is physiological and psychological responses to exercise when wearing the different types of clothing. The second, which will hopefully be a future post is on the environmental side.
Every backpacker knows that cotton kills. This may sound like an over exaggeration, unfortunately it is not. Cotton, and other natural fibers are known for holding onto moisture. This means that if you sweat or you get wet from the environment (humid air, fording streams, rain, snow), cotton clothes are going to hold onto all of the moisture. As you cool down, or the air temperature drops, the moisture in your clothes cools down and you get cold, really cold.
Okay, fine, so despite the durable protection they offer, jeans may not be the best option for backpacking, but surely going for a run in a cotton shirt isn’t that big of a deal. Brazaitis et al (2010) studied the difference between intense exercise in hot and humid environments while wearing a long sleeved cotton or polyester shirt. During exercise, the polyester shirt allowed for greater sweating efficiency and it held less moisture compared to the cotton shirt. There weren’t really any differences between the two in terms of the psychological comfort and how warm the participants got overall. During recovery however, skin temperature returned to normal faster and rates of shivering/sweating perception were lower in the synthetic shirt versus the cotton one.
De Sousa, Cheatham, and Wittbrodt (2014) found similar results with the addition that rectal temperature (woohoo what fun) was significantly lower during the last 15 minutes of a 45 minute work out in individuals wearing the synthetic shirt.
So, as someone who grew up skating in short sleeves in an ice rink and therefore struggles to go for a run in the heat, I’m going to keep plugging away in my synthetic clothes, at least until I look into the environmental side of things.