Frank Pernett is originally from Colombia. He has been freediving his whole life and been involved in the deep freediving and freediving competition scenes for many years. He is currently based in Sweden where he is working towards his PhD under the watchful eye of freediving scientist Erika Schagatay Frank is a wealth of knowledge about freediving science and physiology and today we discuss some of the traditional topics of freediving science that interest us most as well as some new approaches to understanding the dive response and we talk in detail about what can cause lung squeeze and what protocols we might follow to prevent them. In this episode we discuss: Frank is from a Columbian island, San Andres in the Caribbean Sea. Frank has been freediving since he was a kid. He moved to Sweden to work on his Phd with Erika Schagatay. How Vertical Blue has changed over the years. What makes freediving such a unique sport? Frank's main interests and areas of research. Common misconceptions about freediving Deep dive into the dive response (bradycardia and vasoconstriction). A description of vasoconstriction. The relation between vasoconstriction and depth. Is a lower resting heart rate better for freediving? CO2 and CO2 tolerance. About early contractions and stretch receptors. How is CO2 actually measured in the  body. Hypoxia and black out. How oxygen and CO2 are affected by fasting and diet. Lower temperatures to reduce O2 consumption. Franks experience with squeezes and how he overcame them. What would Frank research with unlimited funds? Why does Frank freedive?