Best For: Training The TrailTrainer LS Crew is a breathable, durable long-sleeve built to keep you cool and dry during high-output field training and ruck sessions. Quick-drying 100% polyester with antimicrobial treatment fights sweat and odors so you stay fresh longer. Strategic durable knit fabric delivers abrasion resistance where it counts for backpack training. Underarm gussets, raglan sleeves, and laser-cut venting between the shoulder blades maximize unrestricted movement and airflow. Laminated flat-lock seams on the front deliver chafe-free comfort and a seamless feel. Wear it solo in warm weather or layer over it when temperatures drop—this is the training tee that performs from the trail to the gym and beyond.