#178 | Marco Altini | HRV4 Training

Marco Altini is a scientist, developer and athletic coach who’s work centres on the intersection of health, technology, and human performance.In 2012 he founded HRV4 Training, a mobile platform that revolutionised physiological tracking by becoming the first app capable of reliably measuring heart rate variability (HRV) using a smartphone camera.In this episode we discuss:Donny has been using  Marco’s HRV4 Training APP for ten years now.First we fill Marco in on what freediving actually is!Marco is originally from Italy but has spend most of 20 years between the USA and the Netherlands.After returning to university to study sport science he became a coach to athletes and advises some companies in the wearable space.As a recreational athlete Marco focuses on trail running.What is HRV/Heart Rate Variability?HRV is an indirect proxy to our nervous system’s response to stress.The optimal range for HRV is determined only for the individual, it is not a range that applies to the general population as a whole.There is a strong genetic component to HRV.How a reading is taken using the HRV4 Training APP.The difference between through-the-night measurements and on-the-spot measurements in the morning.Should you lie or sit to take the HRV reading?HRV trends may help to predict incoming sickness.What is parasympathetic suppression in athletes?What is the difference between rMSSD and SDNN?How are the proprietary scores used by Garmin, Suunto, etc?A question from Patreon supporter Bizo Silva about premature atrial contractions and other kinds of arrhythmia.A question from Patreon supporter Brady.How do ‘recovery’ protocols involving sauna and cold-plunge for example, affect HRV.What are the main stealth stressors affecting HRV?Why does he trail run?For all episodes of The Freedive Cafe Podcast, information about freediving courses, coaching, workshops and retreats in Dahab, Egypt, visit www.truedepthfreediving.comTo support on Patreon: www.patreon.com/freedivecafe

Olavi Paananen is a Finnish entrepreneur who recently broke the CMAS World Record for freediving under ice, without a wetsuit.In this episode we discuss:Olavi lives in Espoo and was born in Iisalmi, Finland. Donny also used to live in Finland!Olavi dived 165 metres under ice with bifins to earn a world record!His dad worked in a swimming pool and Olavi spent hours every week there.He did his first freediving course in Finland and worked up to instructor level and took part in some competitions.The depth season in Finland: Baltic Sea, quarries and lakes.Question from Patreon supporter Frannie about why he does this and also from Michaela Werner.David Blane went to Finland.Olavi explains the set up of the Ice Challenge Finland 2026 competition in which his latest record was set.Video of Olavi diving under ice.Extremely high safety standards for diving under ice.A rescue situation on a 110m under ice DNF dive.About the team that supports Olavi.Talking about Iiris Ala-olla performing static without a suit in freezing water.Olavi explains his pre-dive routine, before getting under the ice.How is he feeling during the surface protocol?Post-dive saunas on skis.How does Olavi train for such a demanding dive?Question from Patreon supporter Emile about the health-benefits of cold-water immersion.Donny reminisces about his time spent in Finland.What kind of complementary training does Olavi do out of the water?About blood-flow restriction training, Kaatsu.How seriously does he take his nutrition and supplementation?Question from Patreon supporter Jack about fundiving in cold water.There will be another Ice Challenge Finland in 2027.DESERT ISLAND QUESTIONS | Patreon Exclusive Content.Why does he freedive?For all episodes of The Freedive Cafe Podcast, information about freediving courses, coaching, workshops and retreats in Dahab, Egypt, visit www.truedepthfreediving.comTo support on Patreon: www.patreon.com/freedivecafe

Kalamata Freedivers is a freediving school and training facility located in Kalamata Greece, run by Nejc Likar and Nikos Gkagkanis.In this episode we discuss:Today we are talking with Nejc Likar from Slovenia and Nikos Gkagkanis from Greece.Nejc was previously in Panglao, The Philippines before Greece.Nikos is from the northern part of Greece and his father was a spearfisher so he started very young with freediving. He spent time on Crete before moving to Kalamata.Nejc was Nikos’ instructor.How is freediving in Crete?Was it easy to get set up in Kalamata?Donny visited the centre in Summer of 2025.The logistics of running such a freediving centre.How long is the freediving season in Kalamata?They have four boats at Kalamata Freedivers!The challenge of getting things done in Greece.What goes in to choosing the team at Kalamata Freedivers?Do Nejc and Nikos also like to dive deep and have competition aspirations?Plans to organise competitions?Plans for the future of the centre, special dive experiences and trips abroad.Desert Island Questions SectionHow to find Kalamata Freedivers.For all episodes of The Freedive Cafe Podcast, information about freediving courses, coaching, workshops and retreats in Dahab, Egypt, visit www.truedepthfreediving.comTo support on Patreon: www.patreon.com/freedivecafe

William Trubridge is one of the most celebrated freedivers of all time, achieving multiple world records, winning multiple world championships and diving 102m in CNF (No Fins).In this episode we discuss:William appeared first on Episode #69 of The Freedive Cafe Podcast and then again on Episode #98.Inkfish organisation and research conducted into freediving physiology.Deepest arterial blood samples every taken at 80m depth.Hyperventilation is good now! Are we all hyperventilating unknowingly before dives?Shout out to Dave Mullins.Shout out to Tom of Get Ecstatic in Singapore for sharing...An Unusual Pool Freediving Accident - Temporary Paralysis of All Limbs and Breathing Muscles.How has William’s recent competition performance been?Does he plan to retake his long-standing CNF world record from Petar Klovar?Deep Water podcast recommendation by Lydia Gard.The 2023 Vertical Blue doping controversy in freediving involving Petar Klovar, Vitomir Maricic and Sanda Delija.Donny’s own part in the controversy with regard to his initial insulting comments made towards the Croatians which he followed up with an apology video, and William’s belief that he flip-flopped on the issue and muddied the waters.William’s opinions on the Enhanced Games, the multi-sport event where the athletes are allowed to use performance enhancing drugs.How do we move forward in the sport of freediving to improve doping control to the satisfaction of all the athletes?FAIR - Freediving Athlete Integrity Regulation and Multi-modal Deception Detection.His thoughts on a recent viral video of Petar Klovar blacking out and a bad squeeze (lung barotrauma).About The Mental Immune System. What is the deeper dimension of freediving?For all episodes of The Freedive Cafe Podcast, information about freediving courses, coaching, workshops and retreats in Dahab, Egypt, visit www.truedepthfreediving.comTo support on Patreon: www.patreon.com/freedivecafe

Jack Webb is an up and coming deep freediver from Far North Queensland in Australia. He recently dived 113m in competition in Dominica.In this episode we discuss:Jack just wrapped up a retreat up in Far North Queensland.Jack has been spearfishing since he was a kid.Jack’s school Freediving Far North Queensland is doing its depth sessions in two 65m deep lakes, Lake Eachem and Lake Barrine.About the crocodile in the lake.Jack and Donny met in Dahab in 2022 when there were both diving in the 70m range.How Jack got stopped by a squeeze and other health issues and how he overcame them.Shout out to Julia Mouse in at Apnea Bali.Pepsin, silent reflux, Costochondritis.Shout out to Jack’s coach Dean Chaouche who appeared on episode #95 of the podcast.Journey to the nineties and his first national records. Shout out to Federico Mana who appeared on episode #84 of the podcast.Shout out to Matt Yang from China.How was the  first 100m dive?Jack’s transformational trip to Dominica where he dived 113m.How does his training routine work?How he structures his deep dive routine and his deep dive sessions.Has he had any trouble with hypoxia so far?What does he do for his mental game?Jack’s nutrition and supplement strategy.DESERT ISLAND QUESTIONS - Patreon Exclusive ContentWhy does Jack freedive? For all episodes of The Freedive Cafe Podcast, information about freediving courses, coaching, workshops and retreats in Dahab, Egypt, visit www.truedepthfreediving.comTo support on Patreon: www.patreon.com/freedivecafe

Martin McPhilimey is a respiratory and sleep scientist by background and the founder of The School of Breath Science.In this episode we discuss:Martin joined me from Western Australia where he is based.He is originally from Coventry in England.Martin is a respiratory and sleep scientist by background and the founder of The School of Breath Science.Breath Science Certification Breathing, Nervous system, Sleep, Breath-work, Psychology and Human behaviour.Research on max sprints and lactate clearing capacity of the diaphragm.Diaphragm is type 1 muscle fibre. Type 1 muscle fibres uses a lot of lactate as a fuel source.Adaptations that the diaphragm creates from inspiratory muscle training improves it’s ability to use lactate as a fuel.About CO2 tolerance and air hunger/urge to breath.Breathing rate is driven by emotionWhat are chemoreceptors?Martin has an eight litre lung capacity and held his breath for 3:30 on his first attempt.What can someone do if their nervous system is stressed?What benefits do hyperventilation style practices have for general health?On intermittent hypoxic training and high altitude training.How to improve sport performance with a sleep protocol.What breathing techniques calm us down before big performances?The magic of the controlled exhalation.Yogic breathwork/pranayama.How to address traumatic experiences that happen during freediving.Trauma may be more likely to impact on a person who is more hypercapnic.HRV measurements and their real-life use.Interoception and those who struggle with it.Desert Island Questions - PATREON EXCLUSIVE CONTENTFor all episodes of The Freedive Cafe Podcast, information about freediving courses, coaching, workshops and retreats in Dahab, Egypt, visit www.truedepthfreediving.comTo support on Patreon: www.patreon.com/freedivecafe

Pedro Tapia is a Mexican freediving athlete and the deepest unassisted freediver in the Americas, diving almost 120m with the mono fin and 88m in No Fins.In this episode we discuss:Pedro was training for a pool competition at the time of recording.Pedro won Vertical Blue in 2023.Pedro has a history of alcohol abuse and is now in recovery.He has been sober for 6 years.He was born and raised in Mexico City, Mexico.He is now based in Playa Del Carmen.He was working as an entertainer in resorts.Donny discusses similar issues from his past.Quitting a destructive addiction is never easy. If you need help, reach out to someone and ask.We mentioned r/stopdrinking on Reddit, Alcoholics Anonymous, SMART and Narcotics Anonymous.Discovering freediving through Tinder!All about the Cenotes, fresh water sink-holes in Mexico.Shout out to Pranamaya and the Azul Freediving Challenge.Pedro is essentially self-taught in freediving and doesn’t have a coach.Pedro progressed very quickly.He is now struggling with the mental game in dynamic freediving.Shout out to Samo Jeranko and his latest interview on the podcast (#157).How Pedro periodises through the year and what a typical week of training looks like.Pedro is also working as a coach and instructor as well as training at the same time.Is Pedro using partial or fully empty lung dives?Pedro has a background in gymnastics during his teenage years.How does Pedro maintain his strength training when he is training?Pedro is actively doing cardiovascular exercises.On the benefits of sauna and possibly ice bath.Pedro eats a plant-based diet with added eggs.What supplementation does Pedro take (creatine, beetroot powder, omega 3 from algae, protein).On the topic of doping/use of performance enhancing drugs in freediving.Shout out to the Deep Water podcast from the Observer newspaper/Tortoise media/Lydia Gard.Desert Island Questions - PATREON EXCLUSIVE SECTION What does Pedro do for fun when he’s not freediving?For all episodes of The Freedive Cafe Podcast, information about freediving courses, coaching, workshops and retreats in Dahab, Egypt, visit www.truedepthfreediving.comTo support on Patreon: www.patreon.com/freedivecafe

Lisa Davidsson is a psychologist and hypnotherapist from Sweden, now based in Bali. Known as the surf psychologist, Lisa works with clients from all over the world guiding them through their psychological challenges with therapy and mental training, especially in the context of surfing and being in the water.In this episode we discuss:Lisa is from Sweden, she is a psychologist and therapist and is known as The Surf Psychologist.She is now based in Bali.Donny’s surf story with Mickie.Psychological challenges shared between freedivers and surfers.Strategies for the diver suffering from performance anxiety.Lisa strongly recommends hypnotherapy for the deeper work.What is hypnotherapy exactly?How is a hypnotic state induced?How to use hypnotherapy to help heal trauma related to hypoxic episodes and injuries.On using visualisation and how to visualise effectively.On using positive self-talk, mantras, etc.Discussing comparison with others, ego and ego-driven performances.Hemi-sync, Gateway Tapes and binaural beats.Yoga, and yoga meditation.DESERT ISLAND QUESTIONS - PATREON EXCLUSIVE CONTENTWhy does Lisa surf?For all episodes of The Freedive Cafe Podcast, information about freediving courses, coaching, workshops and retreats in Dahab, Egypt, visit www.truedepthfreediving.comTo support on Patreon: www.patreon.com/freedivecafe

Nataliia Zharkova is a Ukrainian competitive freediver who this year (2025), returned to the competition scene after a four year break and won overall silver in the CMAS World Championships, diving deeper than 100m in three disciplines.She first appeared on the podcast on episode #66In this episode we discuss:Nataliia’s first appearance  on the podcast was episode #66.Nataliia was in Dubai at the rime of recording.Nataliia took a four year break from high-level freediving competitions.Nataliia won overall silver during the recent CMAS World Championships in 2025.Her opinions on the incident around Andrey Matveenko’s accident in training before this competition.How long was the preparatory period for the World Championships?A breakdown of the year long period of training.How does she do her tabata workout?How did taking time off from training benefit Nataliia?Is OnlyFans getting in to feeediving?How does she balance training and coaching?What kind of strength training regimen does she have?Why did Nataliia not do CNF this year in the World Championships?Working on tweaking equalisation for the deeper dives and tweaking neutral buoyancy.Experiences with narcosisAttitude towards diet and nutrition.The joys of quitting coffee.We discuss the doping scandal in freediving in depth.DESERT ISLAND QUESTIONS - Patreon Exclusive SectionWhat does representing Ukraine mean for her?Why does she freedive?For all episodes of The Freedive Cafe Podcast, information about freediving courses, coaching, workshops and retreats in Dahab, Egypt, visit www.truedepthfreediving.comTo support on Patreon: www.patreon.com/freedivecafe

Zsófia Törőcsik is a Hungarian freediving athlete who in 2025 became the first female freediving athlete to dive a distance of 300m in the pool and in the same year won gold at the AIDA Depth World Championships; her first ever depth competition.In this episode we discuss:Zsófia’s experience at the CMAS World Championship 2025 and the controversy surrounding the competition and the accident that happened to Andrey Matveenko.Zsófia is from Hungary and credits her family with shaping her childhood in a positive way.She did triathlon for 10 years, also competitively.A first freediving experience in Malta.Joining a pool club in Hungary and focusing on pool training.Zsófia won the AIDA Depth World Championships in 2025.How did a background in triathlon help Zsófia become a world champion in freediving?Zsófia’s complementary training for freediving, including lots of strength training and biking.The joys of living and training for freediving in Budapest.What does a typical week of training look like?A question from Patreon member Marc about the frequency of max and sub-max dives compared to shorter dives.A question from Patreon member Rodrigo about her speed during her world record dive.Zsófia was the first woman to dive 300m in the pool.A question from Patreon member Elena about Zsófia’s mental strategies for performing such big dives.She is completely deaf in her right ear due to a mumps infection.Her natural talent for mouthfill equalisation.A question from Patreon member Tom regarding the current level of freediving athleticism and the future potential of freedivers and freediving as a sport.Zsófia is a 37 years old.The importance of maturity in freediving and why there are less young people in our sport.Her approach to  nutrition and supplements.Zsófia works in IT and puts together systems for companies.DESERT ISLAND QUESTIONS - Patreon Exclusive ContentWhy does she freedive?For all episodes of The Freedive Cafe Podcast, information about freediving courses, coaching, workshops and retreats in Dahab, Egypt, visit www.truedepthfreediving.comTo support on Patreon: www.patreon.com/freedivecafe