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Flex Diet Podcast

Flex Diet Podcast

Written by: Dr. Mike T Nelson
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About this listen

 Dr. Mike T Nelson gets geeky with the latest research and scientific findings in the fitness world. Visit www.flexdiet.com to get Flex Diet Certified and www.miketnelson.com for more geeky goodness.2020 - 2022 Extreme Human Performance, LLC Biological Sciences Exercise & Fitness Fitness, Diet & Nutrition Hygiene & Healthy Living Science
Episodes
  • Episode 380: Breathing, CO2 Regulation, and Performance: Deep Dive with Respiratory & Sleep Scientist Martin McPhilimey

    Episode 380: Breathing, CO2 Regulation, and Performance: Deep Dive with Respiratory & Sleep Scientist Martin McPhilimey
    Apr 24 2026
    In this episode, I sit down with respiratory and sleep scientist Martin McPhilimey to take a deep dive into breathing, CO₂ regulation, and how they actually impact performance, stress, and sleep. We get into why respiratory physiology is way more complex than most people think, how his clinical and research background shaped his approach, and why breathwork exploded during COVID with names like Wim Hof and James Nestor. From there, we dig into allostatic load and why piling on high-stress practices—like aggressive hyperventilation or cold exposure—can backfire if you’re already running hot. We also talk about the difference between actually relaxing your system versus just dissociating from it. We cover how inspiratory muscle training can improve performance and recovery, why respiratory rate is one of the most sensitive markers of stress, and question some common ideas, such as “CO₂ tolerance.” We also touch on the risks and limited data around inhaled CO₂ therapies and what actually makes sense to apply in the real world. Sponsors: Daily Fitness Insider Newsletter: https://flex-diet.kit.com/bfa1510fa8 Available now: Grab a copy of the Triphasic Training II book I co-wrote with Cal Deitz here. Episode Chapters: 04:22 Why Breathing Is Complex07:52 Martin’s Origin Story11:20 From Clinics to Online14:57 Breathwork Goes Mainstream20:13 Wim Hof Risks and Load24:06 When Intense Breathwork Fits29:18 Relaxation vs Dissociation31:30 Respiratory Muscle Training35:12 Who Should Train Breathing36:35 Simple Device Protocol37:35 Why Teams Ignore Breathing38:27 Respiratory Rate as Stress39:52 Feedforward Breathing Control42:22 Rethinking CO2 Tolerance46:03 Nasal Breathing Tradeoffs48:28 Testing Limits and HRV50:48 Overnight Rate and Calm54:07 CO2 Inhalation and Risks56:45 State Encoding and Fear01:00:35 Wrap Up and Disclaimers Flex Diet Podcasts you may enjoy: Episode 326: Row Hard, Breathe Easy: Boosting Aerobic Capacity with Dr. Kenneth Jay YouTube: https://youtu.be/hpvKokMBRv4Episode 215: Breathing, Heart Rate, and HRV: An Interview with Dr. Scotty Butcher, The Strength Jedi YouTube: https://www.youtube.com/watch?v=nyVEmi7VHbg Connect with Martin: Instagram: https://www.instagram.com/martinmcphilimey/Website: https://martinmcphilimey.com/ Get In Touch with Dr Mike: Instagram: DrmiketnelsonYouTube: @flexdietcertEmail: Miketnelson.com/contact-us
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    1 hr and 5 mins
  • Episode 379: Physiologic Flexibility Certification Open: Temperature, pH, Fuels, and Breathing for Performance

    Episode 379: Physiologic Flexibility Certification Open: Temperature, pH, Fuels, and Breathing for Performance
    Apr 20 2026

    In this episode, I talk about the Physiologic Flexibility Certification open from April 20 to April 27 and where to get all the details.

    At the core is physiologic flexibility, which is your body’s ability to adapt, perform, and recover across different stressors, not just optimize one thing. I break down the four key systems that drive this: temperature, pH, fuels (carbs, fat, lactate, ketones), and breathing (O₂/CO₂), and how they all work together.

    We also get into why AI can miss the physiology, how a 30-second Wingate hits all four pillars, and how to apply this to real-world training with 40+ practical takeaways.

    Episode Sponsor:

    • Physiologic Flexibility Certification: https://physiologic.miketnelson.com/sales

    Available now:

    • Grab a copy of the Triphasic Training II book I co-wrote with Cal Deitz here.

    Episode Chapters:

    • 00:19 Cert Enrollment Details
    • 01:36 AI Pitfalls and Cold Plunge Example
    • 04:05 Four Pillars Overview
    • 05:26 Breathing Module Deep Dive
    • 06:39 Homeostasis and Why It Matters
    • 07:39 Basics First Then Add Stressors
    • 08:51 Wingate Example All Systems Overlap
    • 12:05 Time Efficient Programming
    • 13:37 How to Join and Bonuses
    • 14:48 Coach as Translator and Course Structure
    • 16:22 Wrap Up and Medical Disclaimer

    Get In Touch with Dr Mike:

    • Instagram: https://www.instagram.com/drmiketnelson/
    • YouTube: https://www.youtube.com/@flexdietcert
    • Email: Miketnelson.com/contact-us
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    18 mins
  • Episode 378: Red Light Therapy: Sunlight, Mitochondria, Sleep, and How to Use Devices Correctly with Ari Whitten

    Episode 378: Red Light Therapy: Sunlight, Mitochondria, Sleep, and How to Use Devices Correctly with Ari Whitten
    Apr 13 2026
    In this episode of the Flex Diet Podcast, I sit down with my good buddy Ari Whitten to talk all about red light therapy (photobiomodulation) and why it’s become so popular lately. We dig into how red and near-infrared light fits into an evolutionary sunlight context, why those wavelengths penetrate tissue differently, and how they can influence mitochondria, recovery, and performance. Ari also breaks down the confusing part most people miss: device choice and dosing aren’t one-size-fits-all, and “more power” isn’t always better, especially for sensitive areas like facial skin and the eyes. We also get into emerging research on sleep and melatonin (including intracellular melatonin), as well as practical considerations such as clothing and light penetration. Ari’s updated book, The Ultimate Guide to Red Light Therapy (2.0), is out now. Sponsors: Daily Fitness Insider Newsletter: https://flex-diet.kit.com/bfa1510fa8 Coming up: ISSN 2026: https://www.sportsnutritionsociety.org/ Available now: Grab a copy of the Triphasic Training II book I co-wrote with Cal Deitz here. Episode Chapters: 04:40 Catching Up Surf Talk07:34 Sunlight vs Red Light08:50 Photobiomodulation Basics11:04 Optical Window Explained15:41 Timing and Circadian Effects19:36 Sleep and Melatonin Links26:00 Clothing and Light Penetration27:36 Red Light for Eye Health29:48 Red Light for Eyesight30:47 Dose and Panel Pitfalls31:52 Deep vs Superficial Dosing35:02 Biphasic Response and Safety38:11 Heuristics for Panel Use40:46 Choosing the Right Device42:17 Optics Distance and Angles44:39 LED Density and Hot Spots46:47 Device Examples and Timing48:31 New Book and Wrap Up53:59 Host Outro and Disclaimer Flex Diet Podcasts you may enjoy: Episode 352: Mastering Heart Health: A Deep Dive into Preventive Cardiology with Dr. Michael Twyman YouTube: https://www.youtube.com/watch?v=hpdMnJSZMf8Episode 206: Advanced Recovery Tactics and more with elite athlete coach Justin Kavanauagh YouTube: https://www.youtube.com/watch?v=OTvYT5P3dWs&t=1s Connect with Ari: The Ultimate Guide to Red Light Therapy: https://www.amazon.com/Ultimate-Guide-Light-Therapy-Revised/dp/0593736559?ref_=ast_author_dpInstagram: https://www.instagram.com/ari.whitten/The Energy Blueprint: https://theenergyblueprint.com/ Get In Touch with Dr Mike: Instagram: DrmiketnelsonYouTube: @flexdietcertEmail: Miketnelson.com/contact-us
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    58 mins
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