Janos Porszasz, MD, PhD

Janos Porszasz, MD, PhD

Adjunct Professor of Medicine, David Geffen School of Medicine at UCLA
Technical Director, Rehabilitation Clinical Trials Center, Harbor-UCLA Medical Center


Exercise and Pulmonary Physiology, Cardiopulmonary Exercise Testing (CPET), Respiratory and Rehabilitation Medicine

Research Description

Dr. Porszasz’s main research interest is to improve lives of individuals with exercise intolerance primarily of respiratory origin. In observational and experimental work, he utilized a wide variety of tests: continuous monitoring of heart rate during work shifts and monitoring of physical activity under work conditions and under unrestricted living conditions in COPD. He has contributed developing continuous monitoring of breathing activity of patients on supplemental oxygen therapy. He leads the pulmonary and exercise physiology laboratory at the Rehabilitation Clinical Trials Center that served as central core laboratory responsible for the inter-center quality assurance and quality control oversight in numerous multicenter clinical trials. He has developed a linearized treadmill protocol for clinical cardiopulmonary exercise tests (CPET) and a noninvasive method to detect airflow limitation during exercise from spontaneous airflow generated during exhalation by the exercising subject. As an extension of this effort they currently work on calculating fraction of dead-space ventilation on a breath-by-breath basis using volumetric capnography.

Since 1999, as Technical Director he has been involved in all clinical trials that have been performed in the Rehabilitation Clinical Trials Center, among them those conducted under NIH supported COPD Clinical Research Network, LOTT and COPDGene and various pharmaceutical industry sponsored trials.


  • MD, 1976, Medical University of Pécs, Hungary
  • PhD, 1996, National Academy of Sciences, Budapest, Hungary


  • US Patent #7628732: Exercise Test Speed and Grade Modification (December 8, 2009)
  • US Patent #7927251: Exercise Test Speed and Grade Modification (April 19, 2011)

Recent and/or Significant Publications

  1. Porszasz J, et al. A treadmill ramp protocol using simultaneous changes in speed and grade. Med Sci Sports Exerc 2003;35(9):1596-603.
  2. Porszasz J, et al. Physiologic Effects of an Ambulatory Ventilation System in Chronic Obstructive Pulmonary Disease. AJRCCM Published ahead of print: 06 Jun 2013 as doi:10.1164/rccm.201210-1773OC
  3. Porszasz J, et al. Sinusoidal high-intensity exercise does not elicit ventilatory limitation in chronic obstructive pulmonary disease. Exp Physiol 2013;98:1102-1114.
  4. Watz H, et al. An official European Respiratory Society statement on physical activity in COPD. European Respiratory Journal. 2014;44(6):1521-37.
  5. Porszasz J, et al. Biological quality control for cardiopulmonary exercise testing in multicenter clinical trials. BMC Pulmonary Medicine 2016 Jan;16:13. doi 10.1186/s12890-016-0174-8. PMCID: PMC4715309
  6. Puente-Maestu L, et al. Use of exercise testing in the evaluation of interventional efficacy: an official ERS statement. Eur Respir J 2016; 47: 429-460.
  7. Varga J, et al. Relation of concavity in the expiratory flow-volume loop to dynamic hyperinflation during exercise in COPD. Respiratory Physiology & Neurobiology 234:79-84. 2016.
  8. Dilektasli AG, et al. A novel spirometric measure identifies mild chronic obstructive pulmonary disease unidentified by standard criteria. Chest. 2016 Jul 21. PubMed PMID: 27452770. Epub 2016/07/28. Eng.
  9. Porszasz J, et al. Effect of tiotropium on spontaneous expiratory flow–volume curves during exercise in GOLD 1-2 COPD. Respiratory Physiology & Neurobiology 2018: 251: 8-15.
  10. Porszasz J, et al. Equipment, measurements and quality control. In: Palange P, Laveneziana P, Neder JA, et al., eds. Clinical Exercise Testing (ERS Monograph). Sheffield, European Respiratory Society, 2018; pp. 59–81