By — William Brangham William Brangham By — Claire Mufson Claire Mufson By — Madison Staten Madison Staten By — Satvi Sunkara Satvi Sunkara By — Juliet Fuisz Juliet Fuisz By — Alexa Gold Alexa Gold By — Zoie Lambert Zoie Lambert Leave your feedback Share Copy URL https://www.pbs.org/newshour/video/horizons/2026/02/the-science-behind-exercise-and-why-its-good-for-our-bodies Email Facebook Twitter LinkedIn Pinterest Tumblr Share on Facebook Share on Twitter Story This will come as a surprise to no one, but exercise is really good for us. But why it works and how it works are far less understood. Horizons moderator William Brangham explores that with Stanford University's Euan Ashley. He's a professor of genomics and cardiovascular medicine and is part of a team trying to understand, at the very molecular level, how exercise changes our bodies, and why. By — William Brangham William Brangham William Brangham is an award-winning correspondent, producer, and substitute anchor for the PBS News Hour. He also serves as the host of Horizons from PBS News. @WmBrangham By — Claire Mufson Claire Mufson Claire Mufson is a journalist and general assignment producer at PBS News Weekend. She produces stories on a wide range of topics including breaking news, health care, culture, disability and the environment. Before joining PBS News, she worked in Paris for French public broadcasting channel France 24 and for The New York Times. By — Madison Staten Madison Staten By — Satvi Sunkara Satvi Sunkara Satvi Sunkara is a producer for PBS News. By — Juliet Fuisz Juliet Fuisz By — Alexa Gold Alexa Gold Alexa Gold is an associate producer for PBS News. By — Zoie Lambert Zoie Lambert Zoie Lambert is an associate producer for PBS News.