Podcast
The MicroCast
Hosted by Microcosm Coaching · EN
The Microcosm Coaching Podcast helps endurance athletes—whether you're a road runner, trail runner, or training for your first marathon or 100-miler—get more out of their training with evidence-based advice, effort-based coaching, and expert mindset support. Hosted by professional coaches and athletes, each episode explores practical strategies for race prep, running recovery, mental performance, and sustainable training. If you want to build fitness, avoid burnout, and find more joy in running, you're in the right place.
35episodes
Episodes
Newest firstAll episodes
What Fitness Actually Is: The 5 Systems Every Runner Trains (Plus Running in Wildfire Smoke)
2w ago00:56:53Tap to summarizeWhat is fitness, really? VO2 max, lactate threshold, running economy, durability, and neuromuscular power — in this episode we break down the five distinct systems hiding inside that one word, how each one develops, which respond fastest to training, and which age best. If you've ever chased a watch number and wondered why your race results didn't follow, this framework explains why "getting fitter" is actually five separate questions — and how periodizing your training over years brings them together on race day.We also answer a timely listener question about running in wildfire smoke: what PM2.5 actually does to your lungs, how to use AQI (and its limits), CDC guardrails for exercising outside, when to move to the treadmill, and how to set your line in the sand before race day — including what to do if smoke rolls in mid-race.Plus Hot or Not: gravel running, Garmin's heat acclimation metric, photochromic lenses, and whether bells or eye patches actually deter mountain lions (spoiler: your voice works better).Send us your Hot or Nots and listener questions: microcosmcoaching@gmail.comCurious about coaching? Join the Foothills tier — $10/month for twice-monthly Ask-A-Coach calls and our Slack community of 200+ athletes. Use code FOOTHILLS10 at microcosm-coaching.com
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Heat vs. Altitude Training for Runners: What Actually Works (+ Golden Hour, Probiotics & Time-Based Training)
3w ago01:04:38Tap to summarizeHeat training and altitude training are two of the most obsessed-over (and most misunderstood) tools in endurance running. In this episode, Zoë and TJ break down the actual science: what heat adaptation does to your blood plasma, why "poor man's altitude" is a myth, and how the EPO-to-hemoglobin response really works up high. They cover who should bother with heat or altitude training at all, the two questions to ask before you start, and why fundamentals like consistency, sleep, and fueling beat every environmental hack. You'll hear practical guidance on hot bath protocols, ferritin levels, live-high-train-low, and the 21-days-or-24-hours rule for racing at altitude. Plus: coach spotlight with James Nance, a listener question on time-based training in the mountains (the body doesn't know miles, it knows stress), and hot-or-not takes on golden hour and probiotics. Curious about coaching? Our Foothills tier is $10/month for twice-monthly Ask-A-Coach calls and a 200+ athlete Slack community. Use code FOOTHILLS25. Join at microcosm-coaching.com or reach out at microcosmcoaching@gmail.com.Coaching & Foothills tier: microcosm-coaching.comEmail: microcosmcoaching@gmail.comFoothills promo: FOOTHILLS25 ($10/month)
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Durability: How to Stop Fading Late in Races (Plus Antihistamines, Yard Work & the "Ultra Bod" Myth)
Jun 1700:57:29Tap to summarizeDurability is the word every endurance runner has latched onto — but what actually is it, and how do you build it? Zoë and TJ break down durability for marathon and ultra runners: the difference between aerobic durability (heart rate drift and cardiac decoupling over long efforts) and mechanical durability (the eccentric loading that blows up your quads on late-race descents), why a smaller engine that doesn't fade beats a bigger one that falls apart, and why the only real path is years of consistent, recoverable volume. There's no shortcut — you have to put in the time to get to the place where you can put in more time.Before the main discussion, they take on three listener "hot or not" questions: whether antihistamines like Claritin really blunt training adaptations (the dose in that study matters more than you think), why swapping a strength session for yard work doesn't count, and the truth about chasing an "ultra bod" — energy availability, why underfueling undermines the adaptations you're working for, and why body composition is an output of training, not a lever to yank on. Plus downhill technique, easy volume, and TJ's three biggest coaching pet peeves.Curious about coaching but not sure where to start? Join our Foothills tier for $10/month — twice-monthly Ask-A-Coach calls and a Slack community of 200+ athletes. Use code FOOTHILLS25 at microcosm-coaching.com.—microcosm-coaching.com | microcosmcoaching@gmail.com
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AI vs. Human Coaching, Hiding Your Heart Rate in Races, Cramps & Training in Humidity
Jun 1001:04:26Tap to summarizeSign up for our open house here!https://docs.google.com/forms/d/e/1FAIpQLSc0KnmFGBxZNYqTAZDNFSRUL86UXK7gCIVDDlLtWJBp5WoVvQ/viewform?usp=headerAI vs. human coaching is the big question this week: can a chatbot really build your training plan, or is it a premium cookie cutter? Zoë and TJ break down what coaching actually is — the plan plus the relationship, communication, and buy-in that no model replicates — and dig into the research, including why studies lag behind the tools athletes are actually using, the 2025 analysis pointing toward hybrid human-plus-AI models, and why AI is a good summarizer but a poor authority. Before that, three rapid-fire segments: why you should hide the heart rate field while racing (and trust RPE instead of a signal that lags 30–90 seconds and gets polluted by heat, caffeine, and sleep debt), whether Hotshot actually fixes muscle cramps and side stitches or just floods your mouth with a sensory distraction, and how high humidity wrecks evaporative cooling, spikes your RPE, and slows your pace — plus why heat training isn't the biohack shortcut Instagram sells. Practical, evidence-based, and skeptical in the best way. Questions or hot takes? microcosmcoaching@gmail.com. Join the community on the Foothills tier ($10/month, code FOOTHILLS10).
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Building the Long Run: Endurance, Fueling, and the Mental Game of Going Long
Jun 300:53:59Tap to summarize🏃 Microcosm Open House — Wednesday, June 11th at 5:30pm MT (virtual). Meet the coaches, ask anything, no pressure. Sign up: https://docs.google.com/forms/d/e/1FAIpQLSc0KnmFGBxZNYqTAZDNFSRUL86UXK7gCIVDDlLtWJBp5WoVvQ/viewform?usp=header💪 Want coaching without the full 1:1 commitment? Join Foothills for twice-monthly Ask the Coaches sessions — $10/month with code Foothills10 at microcosmcoaching.comLong runs, ultramarathon training, and fueling are at the heart of this all-time favorite episode, back by popular demand. Kristin Layne and Kyle break down how to actually build long run duration without breaking down — and why the biggest barrier to going long usually isn't fitness.They cover the physiology and psychology of pushing into unfamiliar durations, why you should think in time rather than miles, and how to grow your long run gradually (a good rule of thumb: keeping it under about 30% of weekly volume). You'll learn why you don't need to run your full race distance in training, how back-to-back long runs build confidence and durability, and where RPE should sit so you're building fitness instead of digging a fatigue hole.From dialing in 60–90g of carbs per hour and training your gut, to strength work for late-race durability, to mental tools like segmenting and telling the difference between uncomfortable and dangerous — this is a complete blueprint for stepping up to your first 50K, 50-miler, or 100. Give yourself the runway, and you can absolutely do it.
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How to Know If Your Training Is Actually Working (The N of 1 Experiment)
May 2701:07:32Tap to summarizeSign up for our free open house here! (https://docs.google.com/forms/d/e/1FAIpQLSc0KnmFGBxZNYqTAZDNFSRUL86UXK7gCIVDDlLtWJBp5WoVvQ/viewform?usp=header)How do you know if your training, supplements, or recovery hacks are actually working — or if you're just fooling yourself? Zoë and TJ break down the science of the N of 1 experiment and how to self-coach intelligently in a world flooded with biohacks, miracle protocols, and "this one weird trick" content. Borrowing Feynman's first principle — you must not fool yourself, and you are the easiest person to fool — they walk through six cognitive biases that trick endurance athletes into believing something works when it doesn't: regression to the mean, the placebo of the shiny new toy, confirmation bias, the novelty honeymoon, comparison traps, and sunk cost. Then they get practical: how to actually test an intervention, change one variable at a time, define success before you start, and ask the question that cuts through the noise — compared to what? Plus a coach spotlight on James Nance, TJ's road back to Leadville, and Zoë's day-by-day approach to managing an Achilles flare-up. If you've ever overhauled everything after one bad race or wondered whether your $80 ketones are doing anything at all, this one's for you. Reach out anytime: microcosmcoaching@gmail.com.
Transcribe →The 5 Metrics That Actually Matter in 2026 (And Why Most of Your Data Is Noise)
May 2000:58:11Tap to summarizeCheck out the fuel tracking app here! FuelFlowRunning metrics, wearables, and training data get a reality check this week as Zoë and Kylee Van Horn cut through the noise of HRV scores, readiness ratings, and AI coaches to name the five numbers that actually move the needle in 2026. The episode opens with a familiar character: the athlete double-fisting a Whoop and a Garmin who hasn't strung four consistent weeks of training together in six months. From there, the conversation breaks down what makes a metric genuinely useful, is it actionable, is the signal strong enough to act on, can you verify the underlying measurement, and does it tell you something your body isn't already saying? Then comes the countdown of the five that earn a spot on your watch: rate of perceived exertion (the master metric), consecutive weeks of consistent training, your 14-day sleep average, your long run as a percentage of your 30-day max, and carbohydrate intake per hour on long runs. Along the way: why one bad night of sleep won't break you, the 2025 research linking a single oversized long run to a 128% jump in injury risk, and why most runners fuel with far fewer carbs than they think they do. Evidence-based, occasionally unhinged, and a genuinely useful nudge to audit what you're actually tracking. Questions or hot takes? microcosmcoaching@gmail.com
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Running Economy Explained — 5 Levers That Work, 4 Myths to Ignore
May 1300:52:16Tap to summarizeRunning economy is one of the most misunderstood concepts in endurance training — and one of the most trainable. In this episode, Zoë Rom and TJ David break down what running economy actually is, why it matters more than VO2 max for marathoners and ultra runners, and the specific levers you can pull to get more output for the same input. Using the analogy of miles per gallon, they explain how two runners with identical VO2 max can run race times that differ by 20+ minutes — and what's going on under the hood to explain the gap.The conversation covers the seven physiological factors that determine economy, from tendon stiffness and motor unit recruitment to substrate utilization and thermoregulation. Then they dig into the five interventions that actually move the needle: strength training, plyometrics, strides, hills, and consistent aerobic volume over time. Finally, they bust four of the most persistent running form myths — that you need to run 180 steps per minute, that mid-foot striking is automatically better, that super shoes are cheating, and that form drills will fix your mechanics.If you're an intermediate runner who feels like you've plateaued despite logging the miles, this is the episode that explains what's missing. Plus a coach spotlight intro with Microcosm's Zachary Russell.
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How Hydration and Sodium Make or Break Your Race
May 701:01:22Tap to summarizeHydration is one of the most overlooked levers in endurance performance — and one of the most punishing when you get it wrong. In this episode, Zoë and TJ unpack why dehydration is so much more than feeling thirsty, walking through the cascading downstream effects on your gut, your blood, your muscles, and ultimately your race result. They cover gut osmolality and why a too-concentrated drink mix actually pulls water the wrong way, the link between plasma volume drop and cardiac drift, and why dead legs late in an ultra often trace back to a sodium problem rather than a fitness one.The conversation then turns to the practical side: how to DIY your sweat rate test at home, why your sweat sodium concentration is the number that changes everything, and which lab tests Zoë and dietician Kylee Van Horn actually recommend after testing six different options. They also break down why generic 300–800 mg per hour sodium guidance fails most athletes, with real roster examples ranging from 200 mg to over 2,300 mg per hour.Before the hydration deep-dive, Zoë and TJ tackle a thoughtful listener question about the asides they sometimes make regarding endurance training and sexual health. They walk through the RED-S framework, what suppressed libido and menstrual dysfunction actually signal in athletes of all genders, and why these conversations belong in the coaching toolkit rather than as punchlines. Coach Kylee Van Horn at Fly Nutrition is mentioned as a go-to sports dietician for clinical questions.If you've ever had a mystery DNF, persistent GI distress, or fallen apart late in a race for reasons you couldn't pin down, this is the episode to listen to twice.Questions, topics, hot or nots: microcosmcoaching@gmail.com Learn more: microcosm-coaching.com
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Why You Should Always Be Training + Coach TJ's Canyons 100k Race Recap!
Apr 2901:04:20Tap to summarizeThis week we welcome you behind the scenes of Microcosm Coaching with a quick introduction to Coach Zachary Russell, an athletic trainer and strength coach whose multisport background spans Ironman, triathlon, marathoning, and trail running. He shares what kinds of athletes light him up to coach and how his experience across disciplines shapes the way he builds plans.Then Zoë and TJ dig into TJ's recent Canyons Endurance Run 100K, which he completed roughly 80 minutes off his goal time after a brutal stretch of life context, including his dad's ongoing health and the loss of his uncle the night before the race. They talk about how Cliff and TJ restructured the build entirely, doing more base earlier and less intensity later, and yet Training Peaks read his fitness as identical to previous cycles. They get honest about caretaker stress, mental bandwidth, the choice to keep the door open to joy even when training feels heavy, and why the comparison trap between seasons can quietly steal everything.The bulk of the episode tackles a listener question from Delaney, who has noticed the same faces at every ultra and is wondering whether stringing races together actually counts as training. Zoë and TJ define training the way Microcosm uses it, intentional movement with an adaptive purpose, and reframe it as a continuum rather than a binary. They unpack the B race concept, the difference between racing it and running it, the lily pad effect of bouncing race to race without ever integrating what you learned, and the diminishing returns of using events as a substitute for consistency. They also offer a few honest questions to ask yourself, including whether you would still be putting in this volume if nothing were on the calendar, and what it means to build a higher floor in the interstitial periods most runners ignore.Have a question for the show? Email us at microcosmcoaching@gmail.com and check out microcosmcoaching.com to learn more about working with our coaches.
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