Running out of energy from stabbing is a bigger problem I think. you can always sprint away when out of bullets. you cant sprint when yo are already exhausted from swinging knives everywhere.
Knives? KNIVES? Who the hell said I was going to use a freaking knife? Please~! Don't go making assumptions on my chose of armerment. For your information I'm most likely going to be carrying two katanas, a wakazashi, and also a spear of some kind for a little more reach~!. Also, how are you going to sprint anywhere, when you've been surrounded by zeds, that you've been drawing in for miles all around you?