Zombie Cardio

The zombie pandemic is upon you, and despite what’s been portrayed in TV and Movies, all you can do is run away from them. But running takes up energy - lots of energy. Thankfully there are food items scattered about that you can still consume, but in the process you pack in the pounds. The heavier you are, the more energy is used just to run. So now it’s a matter of balancing the need of energy to gaining weight. How far can you go before the unrelenting zombies take you down?