What type of fitness training will be the best?

[Terro]

Been thinking this for a while but if the shtf and you need to bug out then obviously you'd need to b fit?
But what would be the best fitness training to do?
There's the common just go running as far as possible and keep trying to better it
But there is also training like high intensity interval training which I think would be good because you might have to increase the pace of your walk or run if hunting or being chased ect?
What does everyone think?