thanks for asking your question I completely understand your question chest pain in the centre can be due to lung disease , cardiac disease and stomach disorders as you have pain during exertion it can be a cardiac pain like angina. u need to visit a cardiologist or a general physician to get some investigations like chest xray and ecg to rule out any organic heart or lung disease meanwhile you can take a analgesic and a proton pump inhibitor like pantoprazole after disscussing with hou physician thanks / regards feel free to ask more questions may god bless you with good health