Exercise chest pain not related to heart or lungs. what else could it be?

Costochondritis: If your heart and lungs have been'ruled out' as sources of your chest pain( and this is of paramount importance) than inflammation of the ribs as they attach on the sternum or the rib 'lining' itself can become 'inflamed' occasionally w/ exercise. This is generally treated w/ NSAIDs ( ibuprofen, etc.)A diagnosis can sometimes be made by an examination prior to and after ecersise or bone scan . GL!