I voted for "could'nt sprint".
I think this should be added to the game,you should be able to sprint.
Maybe endurance could effect how long you can run,sprint..& may agility could effect how fast you could sprint & jump also.
Obviously weight would have to taken into account aswell.
You could have a sprint meter..imagine being chased by a death claw & you are trying to sprint to cover,knowing your meter is getting all the lower & eventually you gunna slow down.
If your endurance is high you may reach safety,if your endurance is lower you may fall short of the safe area/building etc. something like this could make it more interesting.
Also if you use all your energy from sprinting maybe it will effect you accuracy or fighting,because your tired. I just think i could add more to the game ,thrill wise & tactical wise

Just my opinion