Wearing a mask reduces the spread of Covid-19. This is not debatable. Some have suggested that wearing a mask is necessary when exercising because heavy breathing while exercising by asymptomatic infected individuals can result in significant spread of the virus. Is this true? And what of all the naysayers (aka Karens) who insist that wearing a mask makes it harder to breathe and impairs oxygenation and ventilation? I review the evidence. Lance Panigutti of Without Limits Sports joins me to discuss the impacts of race cancellations on his business and the possibility of moving forward.