When your chect tightens, does it become worse very quickly and become a warm ache, by any chance? See an allergist, ENT or your general practitioner. If they think you might, get a Rx for a cheapie like albuterol(sp).
Having had to use inhalers before I got asthma (given family and personal history, it was a matter of when, not if), if you don't have it, inhalers like advair(sp) and albuterol(sp) will do nothing for you. If you do, they will begin to open you up in a matter of seconds, though which one does best will vary by person.
Being very much out of shape most of my life, having trouble breathing has little to do with being in shape or not (you should be able to breathe fine, just get to panting and such much quicker). Until last year when sealant was put down in the bathroom, I had no troubles breathing aside from allergies (in that case, it was a reflex issue--I have trouble actually relaxing my diaphragm(sp) around flowers and such--nothing like an asthma attack). As of that time, things that normally triggered that, or just getting a bit of dust, cause it to feel like my lungs are closing up.
Oh yea, obligatory
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