The doctor asked me if I smoked?

After checking my breathing patterns the doctor was positive I was a smoker. I do not smoke, but I have realized that I can't holdmy breath near as long as my peers after a class respiratory test. I also didn't have near the capacity they did. I'm in really good shape and exercise all the time, but I wheeze a lot when I run or jog. I have a lot of chest ache too, but my family has a history of heart disease and heart murmurs. Like I said I don't smoke, but both of my parents do. What's wrong with me?