Dr. Mario Thevis is Vice President of Research, Professor, and Head of the Centre for Preventive Doping Research at the German Sport University of Cologne. He is also Director of the European Monitoring Center for Emerging Doping Agents, a forensic chemist, Editor-in-Chief of Drug Testing & Analysis, and a PCC scientist. He discusses challenges detecting microdosing of prohibited substances, new drug tests being developed using exhaled breath samples, recent breath testing field trials, and more.