Marines.

I believe Delta Force is the elites of the elites, am I correct? You have to be the best at... Everything but also completely specialize on one task but be ready to start something completely new if your commander dies or whatever you gotta be ready to take that on.
I didnt get much sleep last night so I may not make a lot of sense.
Anyway, pullups are where there is a bar high over your head, you grab onto it with both hands and pull yourself up until your chin is higher than the bar. They're a lot harder than they seem. O_o
... You Grunt.
Join the Marines son, be a man. =P
Err, unless you're joining the Army Rangers... In which case you're a crazy fucker.