tydaddy-
The key to getting a fast run time is to run consistently 3-4 times a week for at least 3 miles. At least half of these runs should be doing intervals, that is, running at a much faster than normal rate for about 3-4 min then dropping down to a comfortable, but not slow rate for 3-4 mins and repeating 3 times. Also dont forget to stretch and to warm up at a slow pace before starting the intervals or you are likely to get injured.
If you are 8-10% bodyfat that is not much at all. The reason I would guess why you feel you are too heavy is because you are "muscular". Having a big body-builder type physique can actually be a big disadvantage. This is because body-builders have conditioned themselves for lifting weights, which you will do none of at OCS or during a PFT. Dont get me wrong, there is definitely some cross over, but the type of activities important at OCS and important on the pft are strength-to-bodyweight ratio exercises like (situps, pull ups, dips, pushups, etc). The extra muscle that is gained by high weigh/low rep lifting is often not used during the necessary activities. In my opinion, the best workout schedule is one where you focus first on the core types of exercises you need for the PFT and OCS. Get on one of the pull up programs and do it religiously (5X a week). Do three sets of abs until it really stings and then force yourself to do 10-20 more (5X a week). Run every other day and do the interval training. Finally mix in some push-ups (which will help w/ your pullups and prevent injury (100-150 a dayX 5 days).
If you feel that extra muscle is a disadvantage (which it probably is) forget about weighlifting for a while, I promise you, you'll keep the muscle you need. (Also dont take weight-gainer or any of that other crap, you dont want it and you dont need it). Different routines work for different people, but I pretty much stopped weight lifting last spring to focus on these core exercises and scored a 300 pft at the beginning of last summer. I am not 200+ lbs but I know a guy who is and could run well under 18:00, so it is definitely possible to get a good time with hard work. Anyway good luck, I am sure you will do fine!
