how do you know when youre in shape?

Question

how long can you run before you get tired how many push ups can you do non stop you know that kinda stuff

Answer 1

work out till it hurts

Answer 2

Well, first of all you have to set goals for yourself. Make them realistic, and talk to someone that knows what they're talking about when it comes to fitness. Take a look at this site and use it to compare yourself with what they think. These are the Navy fitness standards.
http://usmilitary.about.com/od/navy/l/blnavyfitness.htm