John has spent years training to become a Pararescueman, a member of Air Force Special Warfare tasked with recovering downed military personnel around the globe. He has pushed himself past countless obstacles and trials, except one — holding his breath in the pool. On this episode of How To!, co-host Carvell Wallace is joined by free diving expert and founder of the Performance Free Dive Academy Kirk Krack. Kirk has spent decades mastering the art of lowering his heart rate and increasing his capacity to hold his breath. He has advised everyone from Navy SEALs to the cast members of Avatar 2: The Way of Water. He even helped Sigourney Weaver go without a gulp of air for over 6 minutes! Kirk gives John tips for extending his breathholds under water and explains why all of us should be more conscious of how we breathe. If you liked this episode, check out: “How To Withstand Pain” Do you wonder how to push yourself past your limits? Send us a note at howto@slate.com or leave us a voicemail at 646-495-4001 and we might have you on the show. Subscribe for free on Apple, Spotify or wherever you listen. Podcast production by Derek John, Rosemary Belson, Kevin Bendis and Jabari Butler. If you enjoy this show, please consider signing up for Slate Plus. Slate Plus members get an ad-free experience across the network and exclusive content on many shows—you’ll also be supporting the work we do here on How To!. Sign up now at slate.com/howtoplus to help support our work. Make an impact this Earth Month by helping Macy’s on their mission to bring more parks to more people across the country. Go to macys.com/purpose to learn more. Learn more about your ad choices. Visit megaphone.fm/adchoices