Have lower back pain difficulty walking more than 200m shortness of breath..any idea what the problem could be?

DOE w/ LBP: The cause of shortness of breath with activity (dyspnea on exertion) and lower back pain cannot be readily known by a physician unless you are seen by the doctor in person for an evaluation. These two complaints are very general, have a myriad of causes and likely involve more than one body system or organ. Any answer would be speculative. Seek proper medical evaluation when in doubt.