Flex Diet Podcast

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 makes you a better coach, how Bryan and Mike use (and distrust) AI in coaching and writing, whether coaches should disclose their AI use, why stacking compounds makes personal experiments hard to interpret, how Bryan thinks about TRT and lab markers like HDL, LDL and PSA, and Mike’s simple rower-based cardio plan—and much more.
Bryan and Mike discuss peptides, TRT and other compounds from personal experience and opinion. Nothing here is medical advice; talk to a qualified healthcare professional before changing any medication or supplement routine.
Connect with Bryan:
over50muscle.com
Bryan on Instagram (@bryankrahn)
Episodes you'll enjoy next:
Episode 137: Training Straight Talk with fitness writer, and online physique coach Bryan Krahn: Bryan's previous visit to the show: training straight talk from a fitness writer and online physique coach.
AI Disclosure, Deepfakes & the Death of Expertise — Dean Guedo & Jeb Stuart Johnston — #404: Dean Guedo and Jeb Stuart Johnston on AI disclosure, deepfakes and the death of expertise (Mike mentions Dean in this conversation).
Episode Timestamps:
02:25 Online coaching's catch-22: taking clients you may not be set up to help
04:16 Bryan's niche: from over-40 clients to the over-50 guy, and why parents and older dads fit
06:10 Edge-case clients, referral networks and paying peers for expertise
08:06 Why paying for consults still matters, including Bryan's 1999 consult with Charles Poliquin
11:35 Why AI still struggles with niche training questions: PEDs, zone two and the Thomas Inch dumbbell
17:03 AI inside coaching software, and why chatbots are so agreeable
18:53 Would clients be accountable to a bot, and will live coaches last?
23:48 Should coaches disclose AI use to clients? Everyday AI wins like soundbars and grill repair
27:29 Contest-prep coaches, AI photo checks, and why coaches get second opinions
34:32 Peptide offers and appetite-suppressing drugs: personal experiences, not advice
39:38 DNP stories and risks as the speakers recount them
42:34 Mitochondrial peptides, NAD+ and IV infusions: why stacked self-experiments are hard to interpret
49:39 TRT: dialing in the basics first and working with a physician
52:41 Lab markers: HDL, LDL and PSA, and changing the marker versus the outcome
58:37 Traveling with a TRT prescription: Bryan's border-security story
1:01:25 Mike's rower cardio plan: baseline 2K test, progressive six-minute sessions and a smarter four-by-four
1:10:58 Should writers disclose AI use? Beating the blank page without losing your voice
1:19:06 Wrap-up: coaching availability, training from 50 to 53, and where to find Bryan

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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 his formulation includes a between-meals binder stack, how sleep and the glymphatic system enter the conversation, and what Qualia’s small symptom-questionnaire study can and cannot establish—and much more.
Dr. Kelly discusses his company’s Qualia 2-Day Detox product. Product descriptions and health claims are his views, not independent verification or medical advice; the small study discussed used self-reported symptom questionnaires.
Connect with Greg:
Qualia on Facebook
Qualia on Instagram
Qualia on TikTok
Dr. Gregory Kelly on LinkedIn
Episodes you'll enjoy next:
Episode 352: Dr. Dan Pardi on Stem Cells, Supplements, and the Future of Health with Qualia: Dr. Dan Pardi on stem cells, supplements, cognitive performance and health habits at Qualia.
Episode 310: Unpacking the Science of Sleep with Dr. Allison Brager: Neuroscientist Dr. Allison Brager on sleep phases, circadian rhythms and performance.
Episode Timestamps:
05:03 Detox skepticism and why this conversation matters
06:35 Why Qualia chose to develop a detox product, according to Dr. Kelly
08:08 Who might need detox support, and Mike's experience with wildfire air pollution
09:42 Dr. Kelly's environmental medicine background and the "last straw" bucket analogy for stress load
12:44 Exposures Dr. Kelly tries to limit: canned foods, strong scents, new furniture, indoor air
15:59 Small, consistent changes versus one silver bullet; Dr. Kelly cites biomonitoring studies
18:59 Water filtration and drinking-water habits
21:32 Larger exposures, the precautionary principle, mold, and skin products
24:18 Sunscreen, sun exposure, and not overcomplicating health choices
28:39 How Qualia approached the formulation, and an explanation of phase one, two, and three liver pathways
33:07 Dr. Kelly's description of the four-step packets: morning and with-meal
36:28 The between-meals binder stack, and a weight-loss study Dr. Kelly cites on stored chemicals
40:26 The bedtime packet, the glymphatic system, and brain demands when learning new skills
44:35 Fat-loss phases, a two-days-a-month approach, and Qualia's small symptom-questionnaire study
48:49 Dr. Kelly's pairings for detox days: sauna, gentle movement, hydration, skin brushing, baths
54:24 Wrap-up: fitting the routine into your schedule, and where to find more information

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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-intensity work, long-duration events, and signs like elevated overnight respiration rate. Enrollment is open from Monday, October 12 through midnight PST Monday, October 19, 2026, and I’m offering direct email access for questions.
Enroll here: https://physiologic.miketnelson.com/sales
Episode Timestamps:
00:00 Welcome and Podcast Focus
00:19 Course Enrollment Window
01:44 Who This Certification Is For
02:48 Why Four Pillars Together
03:41 The Four Homeostatic Pillars
05:05 Systems Thinking Over Silos
08:07 Applying the Framework to Recovery
11:41 Course Structure and Interventions
13:09 Support, Email Access, Next Guest
13:58 Medical Disclaimer and Closing

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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 hypertrophy, how an intermediate lifter can use practice volume and frequency, why great lifters treat the empty bar like the heavy one, how touch, vibration, skin stretch and pressure may influence movement, and how neuroplasticity, lucid dreaming and film study connect to learning skills — and much more.
Connect with Jordan:
Website: themuscledoc.com
Pre-Script: pre-script.com
Instagram: @the_muscle_doc
Pre-Script on Instagram: @pre_script
Episodes you'll enjoy next:
#401 — Psychedelics, Neuroplasticity and the Military-to-Spiritual Journey with Rick Alexander: A former Special Operations combat medic explains how a psychedelic experience reshaped his worldview, and what it taught him about neuroplasticity.
#311 — Maximizing Athletic Performance with Neurology: Insights from Dr. Dylan Seeley: Dr. Dylan Seeley on how applying neurology can improve athletic performance.
Episode Timestamps:
03:47 Internal vs. external cues for strength and hypertrophy
06:24 Longevity culture and why skill comes before loading
09:58 Intermediate bench press case study: practice volume and frequency
17:34 Ed Coan, intent and moving the empty bar like the heavy bar
23:30 Sensory-motor savants: Tiger Woods, Nick Kyrgios and Brian Shaw
27:29 How trainable is the sensory system?
29:35 Foam rollers, kinesio tape and cupping through a neurological lens
32:10 Perception, the electromagnetic spectrum and the limits of our senses
36:23 Mechanoreceptors and vibration
41:05 Light touch, vibration, skin stretch and deep pressure
47:14 Fast feedback: testing and iterating with the nervous system
51:38 Neuroplasticity, psychedelics and learning skills faster
1:02:45 Reality Switch Technology, tropanes and perception
1:05:08 Dreams, hypnagogic hallucinations and altered perception
1:12:26 Lucid dreaming and practicing the deadlift without the load
1:23:19 Film study, muscle memory and watching good reps
1:26:37 Where to find Dr. Jordan Shallow

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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 differ from VO2 max intervals, why elite athletes’ 80/20 approach may not fit your schedule, how Zone 2 definitions can mislead, and what metabolic flexibility and mitochondrial capacity really mean—and much more.
Connect with Martin:
Website: martingibala.com
X: @gibalam
Book: The One-Minute Workout (Avery, 2017; with Christopher Shulgan)
Podcast: Exercise Science
Episodes you'll enjoy next:
#402 — VO2 Max, Zone 2 Training & the Psychology of Human Performance — Ben Skutnik: Dr. Ben Skutnik cuts through Zone 2 hype and discusses VO2 max and aerobic-training evidence.
#387 — Nathan T. Jenkins on Metabolic Flexibility, Aerobic Base, and First Principles: a look at aerobic development, energy systems, and repeated high-intensity performance.
Episode Timestamps:
2:25 Can beginners benefit from HIIT?
4:20 Interval training basics and scaling effort
7:13 Defining vigorous effort with RPE, heart rate, and the talk test
11:32 Designing HIIT workouts around time and preference
13:48 VO2 max intervals versus shorter sprints
16:39 Moderate versus vigorous exercise: guidelines and time efficiency
18:36 Is Zone 2 and the 80/20 rule right for everyone?
22:50 Why Zone 2 definitions and wearables cause confusion
29:12 Do you need an aerobic base before starting intervals?
33:00 Why elite athlete training is not a blueprint for everyone
35:22 What low-intensity volume may do for endurance athletes
38:46 Double-threshold sessions, training stress, and recovery
41:17 Carbohydrate intake and gut training in endurance sports
44:31 Emerging recovery strategies and exogenous ketones
49:12 Lactate supplementation: promise versus current evidence
51:19 Fat max, metabolic flexibility, and mitochondrial capacity
55:31 Exercise Science podcast and evidence over hype

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