If you want to check your fitness level the follwoing physical
fitness test (PFT) is a good way to evaluate you level and determine
what you need to work on.

500 yard swim using breast and/or side stroke in less than 12 miuntes
30 seconds.
10 minute rest
Perform a minimum of 42 push-ups in 2 minutes.
2 minute rest
Perform a minimum of 50 sit-ups in 2 minutes.
2 minute rest
Perfrom a minimum of 6 pull-ups, no time limit.
10 minute rest
Run 1.5 miles in 11 minutes 30 seconds or less or run 2 miles in 16
minutes or less.
Flexed arm test for 10 seconds.

These levels are very obtainable. They do require work and a bit of
practice but the average person can reach these levels with out too
much of a problem. And just to make you feel great if you do reach
these levels they are the same the US military uses as its minimum
requirements. While these are the requirments to be accepted to
BUD/S (Navy SEAL training) they are not unrealistic as all Army
soldiers need to meet these same requirments (except for the swim) in
order to complete basic training (boot camp). You shold work to
imprve your over all fitness level. You would have a much better
chance of surviving an encounter the better the shape you are in.
Also the flexed arm test is being int he pull-up UP position and hold
that position for the full 10 seconds. The felxed arm test is only
required for Airborne paratroopers.

Just a personal note: When I got out of infantry school at Fort
Benning, GA I was able to run 2 miles in just over 12 minutes, do 50
push-ups in 2 minutes and do 80 sit-ups in 2 minutes and do over 20
pull-ups. So yes it can be done if you work hard and you can even do
much better than the above goals.