I made that a while ago for a DeviantArt meme, but it perfectly illustrates the point of this post.
Reason #1: ZOMBIES CHASE YOU.
There are two kinds of people in the world. Those that will survive the zombie apocalypse, and those who will not. You probably know which kind you are.
Zombie preparedness is important. One must always have a zombie plan, and that plan will always be better served by good cardiovascular/musculoskeletal* fitness on your part.
It is highly likely, at some point during the apocalypse, that you will have to run. Run from zombies, run from other survivors who have lost their minds and/or realized that killing you would remove one competitor for dwindling food supplies, run from the inevitable packs of very hungry dogs who think you have or are kibble... There's probably going to be lots and lots of running.
And you should be ready. You should already know how to run, and be able to do it at a decent speed for a good distance (zombies are persistent and have a lot of time to chase you).
There are other elements to zombie preparedness that you should at least be aware of. The most important - more important than physical fitness - is mental preparedness. You have to be ready to face the reality of zombies. You can't waste a lot of time caterwauling and crying and saying, "Dave! Dave! It's me! Why are you trying to eat my brains?!" You wake up in the morning and the zombies are on your lawn. Don't waste the few precious seconds you have to plant sunflowers before the first wave approaches.
If you're prepared, you already have a plan in place, and you stick to the plan. I have a plan**. Running is part of the plan.
And if you think my zombie preparedness is silly, then you belong in that second category of people. The ones who won't believe the zombie apocalypse has happened until it's too late.
*Google spellcheck says this is not a word, but I beg to differ.
**I also have a Robot Apocalypse plan and a Giant Flaming Meteor Plan***, but running does not factor into either of those. Robots are rather faster than me, and you can't outrun the destruction of the entire planetary ecosystem.
***My Alien Plan involves volunteering to be in a human zoological exhibit on their home planet. So it's not really so much a plan as a logical means of avoiding the inevitable extermination of my species.