Why oh why lord, is there no "toggle run" in this game? My left thumb is killing me and my hand is cramping up.

Well sir I suggest regular breaks if this is the case. That or build up your hand muscles and hold the controller differently? I'm not to sure, never had this problem except on a PC.

On the PC it's the letter Q. I have no idea what it would be on a console controller.
Altho, to be honest, I also don't know if that option was always there or if it was recently added via patch. All I know is I accidentally hit the Q while playing the DLC and found myself auto-running into a White Legs camp. <_<

no run button just always run or hold it softer for walking.sounds like you run alot maybe you should try a nice stroll once in a while.or dont play it all day long without a break.or get a joystick pad

So how many hours in a row are you playing this game in a row exactly? :huh:

Fast travel.

Well... in addition to rest, try Sprint mod and Project Nevada which has sprint mod.

Im playing on xbox, so no awesome mods for me. Not sure why they wouldnt add a toggle run for consoles. svcks

Why would you need a toggle run?
Thats the beauty of an anologue joystick..
Precision control over your speed..