The BraveShorts - Navy Gym Short 2.0 - Regularbirddogs invented gym shorts with a built in liner. Athletes, marathoners, and everyone else all say the same thing: nothing fits or feels better. A supportive liner that actually stays put with no bunching or wedging. Secure pockets that don't bounce. Fabric that takes a beating. They're the shorts every other brand has been trying to reverse engineer ever since.