Alright, let's begin this review with the acknowledgement that there are numerous big name manufactures designing great shirts for fitness activities that wick sweat, incorporate breathable lightweight mesh on the back or sides designed to increase ventilation, and almost seamless to reduce skin irritation. With billions of dollars at stake, most of the major manufactures have developed and produced a great line of performance products; however, none have made a better performance shirt for fitness activities than the Under Armour Raid short sleeve t-shirt. The shirt's composition is polyester and elastane which allows the material to stretch when weight lifting or performing cross fit activities. The shirt dries fast and includes anti-odor capability. The shirt is durable and very comfortable. One important note: this shirt is fitted as such that if you are in good shape it is very flattering....if you are not particular comfortable with your present shape, this is not the shirt for you.