Tuberculosis is an infectious disease that causes major deaths worldwide and is a major global health threat for the last 25 years. Pulmonary tuberculosis is characterized by damage and necrosis of lung tissue,unlikeotherlunginfectionswhichmainlyaffecttheairwayswhichcancausedamagethatcauses a decrease in lung resistance in meeting the body's needs, including in meeting the capacity of the respiratory system in supplying oxygen to meet the needs of the lungs. Therefore, this study aims to analyze the factors that influence the Cardiorespiratory Fitness Index in pulmonary TB patients of productive age in Palembang City so that they can predict lung tissue damage that has occurred. This typeofresearchisaquantitativeobservationalanalyticstudywithacrosssectionaldesign.Theresearch wascarriedoutinSeptember2022intheworkingareaofthePalembangCityHealthCenter.Theresults of this study indicate a significant relationship between Index Cardiorespiratory Fitness (VO2Max) and age (p=0.019), body mass index (p=0.016) and HDL levels (p=0.019) but there is no significant relationship to other research variables .