True haha! From what the Warrant Officer I spoke to recently said, its basically situps, pullups, dips, crunches and running. So thats what I focus on, just with more intensity regarding the running!
Guy's focus on your breathing too (Learn how to breath properly Search up elevation Training Mask's But don't go out and buy them and use them unless you have someone with you who is able to help you if you faint or anything else but try breathing only through a straw while exercising!)