NPR's science podcast Short Wave talk about how ultrarunning affects the body, the trend of intermittent fasting and how to protect people's mental health when they talk with chatbots.

Time now for our science news roundup from Short Wave, NPR's science podcast. And we have the show's two hosts here, Regina Barber and Emily Kwong. Hello. REGINA BARBER, BYLINE: Hey. EMILY KWONG, ...