Unless you've found a secure building or nuclear bunker to stay in during the Zombie Apocalypse, where you can put on as much weight and be as lazy as you like, you'll need to be physically healthy if you want to survive.

~ Always maintain moderate levels of fitness. Even if you've found what you think is a secure base, you need to make sure that you're prepared to run or to fight.

~ You won't have a very good chance of surviving if you're overweight or obese, but it doesn't mean that it's impossible. It's more likely that someone who's overweight, but physically active to survive, compared to someone who isn't overweight and does no exercise.

~ Your stamina and strength are the main areas that you should focus on improving. Having good stamina will not only allow you to run further and faster, but it will also improve how you fight. And the benefits of improving your strength are quite self-explanatory.

~ If you're bored with nothing to do, either at home or at your base, doing simple exercises such as pushups, crunches, sit-ups and squats, will improve your health, mentality, and it will give you something to do.