question: Hi  im 1m84 and 76 kilos and i've been eating unhealthy since mid june and yesterday i discovered well ... its when i sit up i feel a little strain and its in my chest in my heart area that i feel a little strain. Its sort of if i do a sit up if jump up and down i might get it put its doesnt hurt i can just feel it and im worried since im just 15 . i have not exercised so i know its hasn't been strained by over exercise. please help! thanks in advance.