Exercise Testing (IMAGE) National Jewish Health Caption Tod Olin, MD, conducts exercise testing with Joanna Zeiger, who suffers from long-term symptoms of COVID-19. Through this testing, researchers have found that the virus actually hinders cell function in those who experience post-COVID syndrome. Credit National Jewish Health Usage Restrictions All multimedia is available for free and unrestricted media use with courtesy to National Jewish Health. License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.