ASK THE GOAT: Running shirts

May. 02, 2013 @ 05:00 AM

Goat: “Is there really a difference between the tech shirt and a cotton tee? I’ve heard that ‘cotton is rotten’ and that the polyester tech shirts are the way to go. Is there any truth in this?” Mary Cotton


Mary: I have long searched for truth as applied to running gear materials. For three years, I have tried, tested and scrutinized various types of fabrics. Here is what I have found so far.

As far as feel while running, tech shirts (which are a synthetic blend almost identical in composition to the polyester shirts of the 1970s) are lighter than cotton ones. This can be a mixed blessing.

For instance, I ran a trail race in a tech singlet that was loose and light. It literally felt like I had no top at all as I was pounding the trails and flying through the course. As I crossed the finish all eyes were on me. Unfortunately, it was because my bright yellow tech shirt was saturated with blood streaks from nipple chaffing. I had no idea it was even happening. I will add, though, chaffing is one of those maladies you rarely notice until you hit the shower.

So, even though tech shirts are lighter and they breathe well, you must make sure they either fit perfectly to avoid undue chaffing, or take precautions. Some folks place adhesive strips in high-chafe areas. I wear a small hydration pack over the shirt that keeps everything seated and stationary. Ironically, cotton shirts have never caused me a chaffing issue while running. Granted, they are a heavier material and they do get soaked with sweat.

Tech shirts are great at pushing some of the heat and all of the moisture from perspiration away from the body. Unfortunately, this also has its pros and cons. The first is the salt residue left behind; the second is the stench.

When the water portion of sweat evaporates, it leaves behind those sweat salts from the digested electrolytes that made running possible. These salts can act as a gritty sandpaper as you run. They can literally file areas of your skin into reddened open sores.

Sweat also leaves behind burned up carbohydrates, proteins and body fat. Similar to how perfume companies concentrate products for maximum effect, the tech shirt creates a highly effective stench film that you will carry throughout the race.

Even so, I have been moving more towards tech shirts for competitions. As long as I ensure the fit is correct and the weather is as I planned, I usually tend to feel better in my tech gear. I have arm sleeves, singlets, shirts, calf sleeves, compression pants and more made from synthetic tech material. I was long a staunch proponent of the cotton shirt and still wear them regularly to train; but as for competition day, I find a nice tech can make me feel a bit more competitive. They usually are custom-made for racing and often have more useable features, such as convenient pockets. Also, they are coming down a bit in price and are highly customizable.

So, Mary, it is completely up to you. Try both in every conceivable situation and see how the two materials stack up. Cotton is far from rotten, but you may hate running in it just the same.