Take it from me, the Physical is a pain in the butt... I did it about 4 months ago. You WILL be there ALL day.
1st you get yo walk around the MEPS center and get your eyes, ears, and blood pressure taken.
then you get a personal examination by a Doc... those guys are hilarious... just watch how they interact with eachother.
Next your Doc puts you in a room with a few other guys (depending on the load they have for the day)... the next part you get to do in your underwear.
You are weighed, measured, and tested for flexibility... simple stuff, like turn your palms up/ down... and some more painful stuff, like walking across the tile floor on our knees (sucks when you have a bruised knee)...
Next you get to take a blood test... we only had one guy pass out (he must have been going Air Force or something)
.
Finally you get to pee in a cup with some other guys in a bathroom... I hope you're a public performer.
Then you get to take your paperwork to the USMC (or whatever service you join) offices... where you wait around and they decide when you should leave for boot.
Now you finally tell some office-jockey that you understand you are going to enlist, get finger-printed, and swear in.
Last but not least, you will probably get to do the pre-IST (initial strength test). At this point, it does not matter what you get on your IST. Passing for entering the USMC is 3 pull-ups in 2 mins and 40 crunches in 2 mins, but that's something you will have to do during recieving (the days before BASIC begins). You will also have to run 1.5 miles in somthing like 13:00 mins...
If you fail your IST when you get to USMC basic training, you get to go into PCP (the physical conditioning program), which is 21 days of fun (or so I have heard).
Ohh, BTW, all of this is after you take your ASVAB.
Anyways, if you have any other question pertaining to the proceedure of entering the USMC, I should be able to help you... or just talk to the recruiter...