When you say "workout" I'm assuming lifting weights because you were talking about your muscles. Although lifting does help your metabolism, it doesn't really help you lose weight if you don't add cardio workouts to your workout routine. As in some of the previous comments, you can't really reduce access fat in specific areas of the body. Rather you lose % body fat throughout your entire body. Lifting is nice and all, but try to add some running, biking, or some other form of cardio into your workout. You might want to try to run 1+ miles before or after you lift weights. This will get your blood pumping and will help you lose that extra fat. If you only lift, it'll just add muscle to your body underneath all that fat. Running, swimming, biking, etc. can help your cardiovascular system which in return can help reduce chest paid, heart problems, and you'll notice that your breathing will improve immensely.
Edit: I was speaking from experience. My chest would always feel uncomfortable and I would have a lot of chest pain. And I got rid of my belly by running...slowly coming back though so I gotta hit those treadmills! Good luck!