A foot scan will determine necessary support. When you arrive at the BMT reception center, one of the first things you'll do is step onto the foot scanners. Most running shops have something similar. They measure where you're putting pressure on your feet when you're standing, as well as measure arches. It spits out a report that will state what sort of support you need, your arch height, and your shoe size for all of the military issued shoes.
You are not "issued" running shoes. Nope! These aren't freebies! You'll head over to a building across from clothing issue where you'll be using your EZ Pay card to purchase your new running shoes. We're not shopping either, you won't have a selection. The sales associates will take a quick glance at your printout and quickly ring you up for the ones necessary for your feet. When I was there, the stability shoe being offered for sale was the Asics Gel 1160. They ended up costing approximately $70.
You are not required to buy their shoes. They might suggest it, to maintain uniformity with the rest of your flight members, but it's not required if you've brought an acceptable pair of your own. You must make a decision though. If you buy their shoes and have your own, one pair will need to go in your civilian luggage. You can't have both in your shoe display. Your selected running shoes will be laundry marked, re-laced, and tied off at the ends.
My Experience and Recommendations
I started training four months prior to leaving for BMT. I went and had my gait assessed at a running shop, which I highly recommend. They'll go beyond the analysis that you'll receive at the BMT Reception Center. A good running shop will have you do the foot sensor, as well as video tape you while you run on a treadmill. They'll see how your foot strikes the surface and determine the best shoe for your feet. Did you know that your running shoe needs to be a size larger than your street shoe? Being properly fitted was a great decision that I made. My shoes were pricier than the BMT ones, but I knew that the sales associates spent time finding the best solution for my needs.
If you purchase a shoe that you intend to take down to BMT with you, find something with a subdued color scheme. This is not the time to splurge on those eye-catching, multi-colored kicks. Remember, you don't want to call unnecessary attention to yourself. We had a trainee who brought down her hot pink running shoes. She ended up with a new pair of Asics, needless to say. Mine were New Balances in tones of grey and white, with some darker cranberry accents, and they worked out fine. Another trainee I knew had the Reebok zig-zag ones, in black with white soles and those were acceptable as well.
If you require or prefer to wear a special insert in your shoes, go ahead and put them in your pre-purchased running shoes and you shouldn't have any issues bringing them down to BMT. Many of the trainees in my flight weren't happy with their Asics, and purchased cheaper inserts at the mini-mall when given the opportunity. Better to come to BMT equipped with what you need then to come up short. With my broken-in New Balances that I'd been used to training in, I never had shin splints and never got any blisters (my boots didn't affect my feet either). Blisters can be a significant issue for a lot of trainees, so if you can prevent that, do it!
If you buy your own running shoes, wear them as the only pair you bring with you to BMT. It'll save you space in your luggage, since you're not allowed to check any bags.
If you're a minimalist runner, know that you won't be able to get away with wearing Vibram Five Fingers. You are required to wear the issued, standard PT socks, pulled all the way up. When I got to tech school, I learned that these shoes were authorized, albeit with a white sock of some sort.
Happy trails, runners!