Flex Diet Podcast

Jonah Rosner is a sport scientist, performance coach, and founder of Marathon Science, translating endurance research for runners and hybrid athletes.

Does everyone really need two to three hours of Zone 2 each week? Sport scientist Jonah Rosner joins Dr. Mike T Nelson to explore when higher-intensity work makes sense, how to separate cardiovascular stress from tissue stress, and what heat training and blood flow restriction may add to an endurance plan.

Expect to learn why time-crunched lifters may benefit from carefully selected intervals, how to separate cardiovascular load from tissue load, why sprinting needs a...

James de Lacey is a strength and conditioning coach with an MSc in Sport & Exercise Science and more than a decade of experience in professional sport spanning professional and international rugby/rugby league. He now focuses on combat sports to prepare fighters under Sweet Science of Fighting.

Do fighters really need zone 2 cardio? Strength and conditioning coach James de Lacey of Sweet Science of Fighting joins Dr. Mike T Nelson to challenge the "big aerobic base first" playbook for combat sports, from heart rate recovery and short-rest sprint intervals to muscle oxygen (NIRS) data. They also dig...

Bryan Krahn has been a personal trainer since 1997, a CSCS since 2005, and a full-time online coach since 2014. He is a fitness writer and the author of two books with Men's Health.

Will AI replace online coaches, or only the ones who stop being human? Veteran online coach and Men's Health author Bryan Krahn joins Dr. Mike T Nelson for a candid, unfiltered conversation about paying for expertise, whether coaches should disclose AI use, personal experiences with peptides and TRT (opinion, not advice), and Mike's simple rower-based cardio plan.

Expect to learn why paying for expertise...

Dr. Gregory Kelly, N.D., is Chief Product Officer at Qualia Life, a naturopathic physician, author of Shape Shift, and former editor of Alternative Medicine Review.

Detox is more than a liver story—and it is not a juice cleanse. Dr. Gregory Kelly of Qualia Life explains how clearance pathways work together, why mobilizing stored chemicals is not the same as eliminating them, and the thinking behind Qualia 2-Day Detox.

Expect to learn why detox skepticism is warranted, how Dr. Kelly thinks about cumulative stress and chemical exposure, what liver biotransformation and elimination mean, why hi...

In this episode of the Flex Diet Podcast, I break down why I built the Physiologic Flexibility Certification (PhysFlex) as a “level two” continuation after you’ve already got the basics of nutrition, training, and recovery mostly dialed in.  I explain how Phys Flex targets four overlapping homeostatic regulators—temperature (heat/cold exposure), pH (acidity/alkalinity shifts), expanded fuels (ketones and lactate), and oxygen/CO2 regulation (breathing)—and why taking a systems view matters more than treating everything in silos. 

I share examples of how these pillars can become the real limiter in recovery and performance, including high-intensi...

Dr. Jordan Shallow, D.C., known as “The Muscle Doc,” is a chiropractor, strength and conditioning coach, and former competitive powerlifter. He is the founder of Pre-Script®, an education company that teaches coaches applied biomechanics and resistance training.

Is getting stronger really about muscle, or about how well your nervous system learns the lift? Dr. Jordan Shallow, “The Muscle Doc,” explains why strength and size follow skill, how your senses shape movement, and how simple sensory inputs may change the way you train.

Expect to learn when internal versus external cues make sense for strength and hyper...

Dr. Martin Gibala is a Professor of Kinesiology at McMaster University and one of the world's leading researchers on high-intensity interval training.

Can short bursts of hard cardio outperform hours of Zone 2 for the average person? Exercise physiologist Dr. Martin Gibala explains how HIIT can improve VO2 max and metabolic flexibility, why elite athletes' 80/20 split may not fit a time-strapped schedule, and how to judge vigorous effort without chasing a perfect heart-rate zone.

Expect to learn how to scale HIIT for beginners, what RPE and the talk test reveal about vigorous effort, when short sprints...

Matthew Paul Clemons, MD, is a diagnostic radiologist specializing in nuclear medicine and body imaging. He is Head of Nuclear Medicine at Radiology Partners Houston and a rectal and prostate cancer specialist.

Whole-body MRI promises a detailed look under the hood—but what can a quick screening scan actually see, miss, and send you chasing? Dr. Paul Clemons explains why a whole-body MRI is a limited study, how incidental findings can lead to further tests, and why standard screening remains the better choice for most people.

Expect to learn how MRI creates images and why sc...

Dean Guedo is an Edmonton, Alberta-based online nutrition coach and strength/nutrition professional with roughly a decade in fitness, athletics and strength sports, and Jeb Stuart Johnston is a National Board Certified Health & Wellness Coach and the Charleston, SC-based founder of Food on the Mind, specializing in emotional eating and food obsession.

Dean and Jeb join Dr. Mike T Nelson for their yearly AI check-in, getting into whether creators should disclose AI use and why deepfaked video is a very different beast than AI-assisted writing. The conversation ranges into dead internet theory, why so much hard-won fitness...

Don Saladino is a New York-based coach and health entrepreneur who has trained A-list clients like Ryan Reynolds, Hugh Jackman, and Blake Lively since founding Drive495 in 2005.

Don Saladino has spent nearly three decades training A-list stars like Ryan Reynolds and Hugh Jackman — and in this episode, he shares the single business lesson he wishes he’d learned sooner. He and Dr. Mike also dig into why Don closed his $2M-overhead NYC gym, how tracking respiratory rate reshaped his approach to Zone 2 training, and the sobering personal loss that changed how he views performance enhancers.

Expe...

Dr. Ben Skutnik, PhD, CSCS*D, NSCA-CPT*D, is an Assistant Professor of Kinesiology and Human Performance Lab Director at Butler University and Head of Nutrition Coaching at Power Athlete.

Dr. Ben Skutnik joins the show to separate fact from fad in aerobic training, debunking zone 2 hype and explaining why VO2 max matters but isn't everything.

Expect to learn why reading scientific literature is its own skill, how uncontrolled variables quietly derail hypertrophy and menstrual-cycle training research, why treating people as fragile backfires, why anecdote in human performance often outruns the research, how "closing the...

Rick Alexander is a depth-psychological counselor, psychedelic practitioner, and interfaith spiritual care provider currently completing his Ph.D. in Mythology/Depth Psychology and a former Naval Special Operations combat medic.

Rick was a Special Operations combat medic until a single psychedelic experience shattered his worldview and sent him back to school to study psychedelic spiritual care. He and Dr. Mike dig into neuroplasticity windows, why “good trip/bad trip” is the wrong question, and what may really be happening in DMT space.

Expect to learn how a rough teenage salvia trip and a later psilocybin expe...

Dr. Dwayne Jackson is a health specialist, medical educator, scientist, and entrepreneur with a PhD in neurovascular physiology.

Mitochondrial peptides may be promising, but they cannot replace the aerobic base that makes their effects measurable. Dr. Dwayne Jackson explains AMPK and mitochondrial signaling, what MOTS-c and SS-31 can and cannot tell us, and why fitness data, training, and recovery come before any experimental compound.

Expect to learn how aerobic fitness supports strength and Strongman training, why lactate clearance and conditioning can become the rate limiter, what AMPK and mTOR signal, how kidney disease changed Dwayne’s...

Emily Werner, PhD, RD, CSSD, IFNCP is Team Dietitian for the Philadelphia 76ers (NBA) and Philadelphia Flyers (NHL), and Nutrition Affairs Sport Lead at Timeline.

Dr. Emily joins Dr. Mike to unpack postbiotics, urolithin A, and why mitochondrial health matters for pro athletes and everyday people alike, digging into the real research behind Timeline's Mitopure and why chasing $200K gadgets rarely beats getting the fundamentals right.

Expect to learn what a postbiotic actually is and how urolithin A differs from other supplements, why old-school and new-school sports dietitians disagree on peptides and supplement fads, how...

Zach Moore is a nutrition and exercise coach based in southern Indiana, coaching clients online and in person.

Zach cuts through the noise of complicated programming and diet protocols to get back to what actually works — minimalist strength training, honest macro-setting, and paying attention to gut health and micronutrient status before chasing anything fancier.

Expect to learn how to build serious strength with far less training volume than you think, why chasing perfect programming conditions is often a waste of energy, how Zach sets carbohydrate and macro targets for real-world clients, when (and when not) to...

Cliff Wilson is a physique coach with over 16 years of experience working with bodybuilders and physique athletes of every level, including 24 world champions and the current natural bodybuilding world champion.

Getting better doesn’t make hard things feel easier—it makes you capable of doing more. Cliff Wilson explains the mental skills behind elite physiques, why context beats internet absolutes, and how great coaches turn research, experience, and failure into better decisions.

Expect to learn why impulse control makes up 20–50% of physique coaching, why you have to learn to dribble before you try to dunk, why pr...

Rick Collins, Esq., NSCA-CSCS, is a lawyer who defends the nutrition and fitness community, a partner at Collins Gann McCloskey & Barry PLLC, and General Counsel to the International Society of Sports Nutrition.

Peptides are everywhere right now, but most of what's sold online as BPC-157 or TB-500 is illegal — and the FDA is about to decide what happens next. Rick breaks down the science, the legal gray market, and why the military's new testosterone screening policy matters too.

Expect to learn what actually counts as a "peptide," how GLP-1 drugs normalized injectable medications and fueled th...

Samuel Brown, M.Ed., CSCS is a Cognitive Performance Specialist for the U.S. Air Force and a strength and conditioning professional who has worked everywhere from collegiate athletics to elite tactical units.

Sam spends his days training Air Force pilots and aircrew who run on nicotine, caffeine, and alcohol — and almost never turn off their nervous system. In this episode he reveals why the toughest operators need recovery just as much as intensity, and what years of coaching in Altus, Oklahoma taught him about real performance under extreme cognitive load.

Expect to learn what Ai...

Dr. Krista Scott-Dixon, PhD, is the author of the 700-page textbook Applied Nutrition Coaching and Counseling for Coaches.

Most nutrition coaches know their protocols — but very few have been trained in what to actually do when a client says something unexpected, breaks down, or simply won't follow the plan. Dr. Krista Scott-Dixon reveals the counseling techniques that most nutrition coaches have never learned — and why mastering them matters more than any protocol. She explains why over-optimized clients are often the most fragile, how AI is eroding the critical thinking skills coaches rely on, and what it really take...

In this episode of the Flex Diet Podcast, I sit down with Paul Oneid, MS, MS, CSCS and Cody Miller for a conversation about rebuilding from injury and the transition from strength sports to endurance training.

Paul Oneid tore both quads and rebuilt himself from powerlifter to trail runner, with coach Cody Miller guiding the transition. They break down the emergent training approach, VO2 max and cardiac adaptations, and the mental side of suffering across strength sports and endurance.

In this episode, you'll learn:

Can you really build more muscle just by rethinking how you dose leucine and essential amino acids? Dr. Daniel A. Traylor, Ph.D. — co-founder and principal scientist of LEUVATE™ — reveals the science behind protein quality, muscle protein synthesis, and why older adults may need twice the protein dose to get the same results as younger people.

We dig into mTORC1 signaling, sarcopenia, the 30g protein absorption myth, GLP-1 drug effects on muscle, and the clinical trial data behind LEUVATE™. If you care about muscle, longevity, or protein strategy, this one is loaded.

Guest Bio

Daniel...

In this solo episode, Dr. Mike T. Nelson introduces the concept of coaching leverage—the idea that effective coaching means multiplying physiological impact by a client's realistic ability to change.

The Flex Diet Certification closes tonight (Monday, June 22, 2026) at midnight Pacific. Get details here.

G...

In this episode of the Flex Diet Podcast, I sit down with Dr. Sara Campbell, Ph.D., Associate Professor at Rutgers University, for a conversation about the bidirectional relationship between exercise and the gut microbiome.

Dr. Sara Campbell returns to discuss her lab's cutting-edge research on the bidirectional relationship between exercise and the gut microbiome — including why consumer gut tests oversimplify a complex ecosystem, how antibiotics devastate exercise capacity in animal models, and why single-microbe probiotics miss the bigger picture of functional guilds. She also shares new findings on short-chain fatty acids, amino acid metabolomics after antibiotic tr...

In this solo episode, Dr. Mike T. Nelson dives into the intersection of AI and coaching. Using his quest to pick up the 175-pound Inch dumbbell as an example, he shows how AI struggles with niche topics where quality training data is scarce — and why that matters for fitness advice.

Topics covered:

Dr. Emily Dow, PhD, RD, is a researcher and registered dietitian working at the intersection of nutrition, resistance training, and gut health.

Does vinegar actually do anything for your gut or your blood sugar? Can you trust a $200 mail-in microbiome test? Emily built her dissertation around questions like these, and her honest answers are a lot more useful than the marketing.

Expect to learn what a 12-week resistance-training-plus-vinegar protocol did (and didn't do) to gut permeability, why a null result in a healthy population is still worth your attention, what the research really says about...

In this episode of the Flex Diet Podcast, I sit down with Dr. Nathan Jenkins to discuss how to improve performance, body composition, and long-term health through the lens of aerobic development and metabolic flexibility.

Nathan shares his journey from exercise physiology and coaching CrossFit athletes to his new role teaching physiology at the University of Georgia School of Medicine. We discuss why metabolic flexibility is such a powerful framework for understanding everything from biochemistry and exercise performance to metabolic disease.

We also dive into interpreting maximal exercise testing data, including VO₂ measurements, EKG analysis, an...

In this episode of the Flex Diet Podcast, I sit down with my friend Tracy Holemeyer (Uncontrollably Me, host of the Other Way to See It podcast) to talk about healing and performance through nervous system flexibility, somatics, and self-awareness, especially with how much stress people are carrying right now. 

We dig into practical tools like orienting, grounding, the “starfish” drill, pendulation, and Tracy’s “core four” (soft eyes, relaxing the tongue, breath pacing for coherence, and soft knees), plus how posture and unconscious habits can shape mood and behavior. We also explore the value of community and coachin...

In this episode of the Flex Diet Podcast, I sit down with human performance specialist and coach Rob Wilson for a wide-ranging conversation that spans music, coach education, and what it really means to train for performance longevity. We dig into Rob’s new book, The Check Engine Light: Tune In Your Body and Mind to Achieve Performance Longevity, and his work educating coaches through ALTIS and with special operations communities.

Rob also shares why jiu-jitsu strength and conditioning still lacks clear performance standards and proposes building sport-specific frameworks (like lower-body clinching demands) before jumping to exercise se...

In this episode of the Flex Diet Podcast, I talk with my good buddy Chad Landers, veteran trainer, strength coach, and author of Building Strength and Muscle After 50, about how to keep gaining strength and muscle as you get older without falling off the “injury cliff.” We dig into why consistency matters most, how progress often drops in steps after injuries, and why smart modifications beat worshipping any single lift. 

Chad shares lessons from coaching clients for decades, including balancing pressing with back work, using better technique (like pause benching), and building conditioning with tools like the fan b...

In this episode of the Flex Diet Podcast, I’m on the road and sit down with strength coach Martin Silva to talk about how to improve body composition, performance, and long-term health, especially for high-achieving clients in the 35–60 range.

We get into unlearning a lot of the nutrition beliefs people bring in, why I still like keeping nutrition simple, higher protein, fewer ultra-processed foods, and how short-term tracking can build awareness without becoming a crutch.

Martin also walks through how he structures coaching check-ins, his own background going from bodybuilding and restriction to a more...

In this episode of the Flex Diet Podcast, I sit down with creatine researcher Dr. Darren Candow from the University of Regina to break down what the research actually says about creatine for muscle, performance, and body composition—plus the newer interest in brain health, aging, and longevity.

We dig into practical dosing (including higher-dose ideas for bone and brain), why timing probably doesn’t matter much, and what the data shows on safety, side effects, and common myths like hair loss. We also talk about creatine in special contexts like sleep deprivation, jet lag, concussion/TBI pote...

In this short Flex Diet Podcast episode, I share a reminder that the PhysFlex Surge enrollment closes Monday, April 27, 2026 at midnight PST, and I give more context on what’s inside the PhysFlex Certification. I explain how Level 1 (Flex Diet Cert) covers nutrition and recovery basics, while Level 2 (Physiologic Flexibility) focuses on becoming more robust and resilient by improving the four pillars of homeostatic regulation: temperature, pH, fuels (including ketones), and air (managing oxygen and CO2). 

I walk through my eustress vs distress model, why most interventions work better with lower intensity and higher frequency, and how mis...

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...

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...

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 in...

In this episode of the Flex Diet Podcast, I sit down with Dr. Scott Sherr to take a deep dive into methylene blue, mitochondrial function, and where the truth lies between online hype and fear. We talk through how methylene blue acts as a redox cycler in the mitochondria, how dosing differs for mitochondrial support versus antimicrobial use, and why high doses or poorly labeled liquid droppers can cause problems. 

Dr. Sherr also shares how he’s used methylene blue with athletes for recovery and endurance, including timing, half-life, and practical ranges he sees most often. We cov...

In this episode of the Flex Diet Podcast, I sit down with Dr. Masha Makeeva, a physician specializing in integrative and regenerative medicine, to get a clear, practical breakdown of hyperbaric oxygen therapy. We talk about why HBOT’s biggest benefit may be reducing inflammation, who it can help most, and how to think about protocols — pressure, oxygen concentration, session length, frequency, and total number of sessions —so you’re not comparing totally different approaches. 

We also dig into where she sees HBOT used most (including cancer support and professional sports), why solid tumors may respond differently than bloo...

A physician buddy asked me whether the general population should focus on cardio or lifting — and I wanted to share my answer with you. In this solo cast, I break down why cardio and resistance training produce different adaptations, offer my go-to weekly framework for getting started, and talk about zone two training, high-intensity intervals, VO2 max assessments, and why compliance beats the perfect program every time. Plus, the Flexible Meathead Cardio Course is open for enrollment through Wednesday.

Sponsors:

Enroll in the Flexible Meathead Cardio course. Enrollment ends We...

In this episode of the Flex Diet Podcast, I sit down with my friend Kristi Storoschuk, a PhD candidate in exercise physiology, to unpack her review paper on zone 2 cardio and what the evidence actually shows. We dig into what “zone 2” really means (including lactate thresholds and why common proxies like heart rate and the talk test can miss the mark), where the 80/20 endurance model came from, and why messaging around zone 2 for mitochondrial function, fat oxidation, metabolic flexibility, and health may be overstated, especially for the general population. 

Kristi explains why higher intensities often produce equal or be...

In this episode of the Flex Diet Podcast, I sit down with coach Kevin Dineen to talk about where fitness and healthcare are headed and whether their merger is a net positive or negative. We dig into why people still default to asking physicians about training and nutrition, the problems created by siloed systems, and what a more client-centered model could look like with coaches, PTs, massage therapists, and physicians collaborating under one roof. 

We also discuss the pros, cons, and liability concerns around coaches using blood work for performance, how hard training can skew lab results, a...