When the Zombie Apocalypse comes what will determine whether you join the Walkers or end up joining the rugged bands of humans will depend on your speed, agility and lower-body strength. Survival here requires speed, strength and endurance. You need to be able to run fast, run long, jump high and be capable of doing it all, all over again as a fresh flesh-rending horde appears around the next corner. Whether you go for the theory that zombies plod along after flesh or run like Gazelles in a pack the only thing that is certain is that those who will survive the onslaught are not going to be slow on their feet.