Originally posted by MP ARREOLA:
... but I have a big problem running
Why? If its a weight thing, I'd work on losing it. If its because you haven't done it much then you just need to get started. You could ease into it by starting a "run/walk" program. For instance, run for 30 seconds and walk for 1 minute. Keep doing this and try to increase you're run time while decreasing (or eliminating) walk time.
If you live close to a good running-shoe store (like Fleet Feet) you might want to consider talking with a salesperson. They can help you pick out the right shoes and can probably help you with starting a running program. The shoes might be a little pricey but one place you DO NOT want to skimp is running shoes. The wrong shoes can really mess you up.
As for the sit-ups and push-ups, it sounds like you got the right idea; just keep doing 'em.
Just make sure you do it at a comfortable pace and avoid injury. The last thing you want to do is get hurt before BCT.
Just my 2 piasters...