What should be the aim of physical fitness?

Your goal for physical fitness should be to always get better at what your trying to achieve. This doesn't mean if your bench press max is 150 to jump straight to 200 the next day. That's a good way to hurt yourself. It simply mean if you can do 10 push ups this week, try to increase to 14 next week. That is a good way to cause muscle confusion and always make your body work a little harder.