Arm sleeves can help with muscle fatigue and soreness by improving blood flow and oxygen delivery to the muscles. The pressure from the compression can also help reduce muscle vibration and damage during exercise, leading to less soreness and fatigue after the workout. However, the extent to which arm sleeves can help with muscle fatigue and soreness may vary from person to person, and the benefits may not be significant for everyone. It's essential to try out arm sleeves during training runs to see if they work for you and if they provide any noticeable benefits.