This week, we find out about survival in extreme environments. We find out how free divers descend hundreds of feet underwater without air, how life thrives beneath the ice in Antarctica, how fighter pilots combat G-forces to avoid blackouts, and how the body copes with exercising at the top of Everest. Also, discover the benefit of breaks between bouts of exercise, how geckos hold the key to underwater post-it notes, and a gene that lets you chat whilst listening to the radio. Like this podcast? Please help us by supporting the Naked Scientists)