The Endurance Lab

At age 49, Marilyn Tarkalson ran a 2:58 marathon, breaking 3 hours after previously running 3:21 and 3:14. Now, at age 50, she’s still trying to get faster. In this conversation, we break down exactly what changed in Marilyn’s marathon training, nutrition, recovery and mindset. Whether you’re trying to run a sub-4 marathon, sub-3:30 marathon, qualify for Boston, break 3 hours, or simply run a fast...

How do you run a faster marathon after 40? Whether your goal is to break 4 hours, run a sub-3:30 marathon, qualify for Boston, or eventually run a sub-3 hour marathon, Andrew Snow argues that the answer may have far less to do with adding harder workouts—and far more to do with building the foundation required to support them. Andrew Snow is a running coach and author of Run Elite, a book that tak...

In this episode of The Endurance Lab, I sit down with Dr. Greg Grosicki, Staff Research Scientist at WHOOP, to explore the science of HRV and HRV-CV and, more importantly, how runners can actually use these metrics to make smarter training decisions. We break down why higher HRV is generally better while lower HRV-CV is generally better, why your seven-day HRV trend can tell you something very dif...

Can you become a fat-adapted endurance athlete while still using carbohydrates to race fast? In this episode, I sit down with Sami Inkinen, endurance athlete, age-group triathlon world champion and co-founder and CEO of Virta Health, to explore how he went from discovering he had prediabetes despite being extremely lean and fit to dramatically increasing his fat oxidation and, at age 50, producing...

Can training your brain help you run faster for longer after 40 — without actually getting fitter? Brain performance scientist Dr. Scott Frey joins The Endurance Lab to explain the science of Brain Endurance Training (BET) and why the brain may be one of the most overlooked determinants of endurance performance. We explore how the brain regulates perceived exertion, pacing and fatigue; how neuropl...

Many endurance athletes think getting leaner automatically means getting faster. But for masters runners, cyclists, and endurance athletes, there is a hidden problem that can quietly destroy performance: underfueling and low energy availability. In this episode of The Endurance Lab, I speak with Rebecca McConville, MS, RD, LD, CSSD, CEDRD, a sports dietitian specializing in endurance nutrition, Re...

Can you become a highly fat-adapted runner without going fully keto — and without sacrificing your ability to use carbohydrates when performance demands it? In this episode of The Endurance Lab, I sit down with exercise and nutritional physiology researcher Matt Carpenter to unpack the science of fat adaptation for endurance runners, including runners over 40. We explore what being “fat adapted” a...

➡️ Join The Endurance Lab Inner Circle on Telegram 👉 https://t.me/TheEnduranceLabInnerCircle Aleksandr Sorokin went from weighing around 100 kilograms, smoking, drinking alcohol, and living an unhealthy lifestyle to becoming one of the greatest ultrarunners in the world. In this episode of The Endurance Lab, Aleksandr shares how he transformed his life, lost the weight, discovered ultrarunning, a...

➡️ Join The Endurance Lab Inner Circle on Telegram👉 https://t.me/TheEnduranceLabInnerCircle In this episode, I sit down with Dr. Aitor Viribay, co-founder of FLF (From Lab to Field), to discuss the science behind exogenous lactate—why elite cycling teams are suddenly interested in it, how it compares with carbohydrates and ketones, and whether drinking lactate could become the next major breakthr...

In this episode of The Endurance Lab Podcast, I sit down with Dr. Kevin Miller, one of the world's leading researchers on exercise-associated muscle cramps. We dive into the latest science behind muscle cramping, why the traditional dehydration theory doesn't fully explain what happens, and Dr. Miller's new Multifactorial Theory of Muscle Cramping. Dr. Kevin Miller is a Professor and Athletic Trai...

Can training in low oxygen actually make you a faster runner without adding more training hours? In this episode of The Endurance Lab, I speak with Dr. Barney Wainwright, Senior Research Fellow at Leeds Beckett University, about the science of hypoxic (altitude) training and why many elite endurance athletes now use it to break through performance plateaus. We discuss how hypoxic training works, w...

Why Ketone Supplements Work Better for High-Carb Runners 🫁 Save $100 on Tymewear Pro Training Membership Code: E-LABTW26 👉 https://www.tymewear.com/E-LABTW26 Most runners assume that if ketones are beneficial, the athletes already producing the most ketones naturally would benefit the most from ketone supplements. But the science suggests something more complicated. In this episode of The Endura...

In this episode, I sit down with running biomechanics coach Paul Mackinnon to break down the science behind efficient running technique. After completing a one-on-one running form analysis with Paul, I completely changed how I think about running mechanics. We discuss why over 95% of runners leak energy through inefficient movement, why improving your running form can improve running economy, redu...

Anar Larsson from Tymewear explains why heart rate, pace, power, and even lactate can mislead runners when trying to find their real physiological Zone 2. They often end up training in Zone 3 instead. We talk about VT1, VT2, ventilation, fat oxidation, durability, and why many endurance athletes accidentally train too hard even when they think they are doing easy aerobic training. 🫁 Save $100 on...

Most runners think about training in terms of mileage, intervals, and long runs. Very few think about heat as a performance tool. But heat training could be one of the most accessible and evidence-based performance levers available to any recreational runner — and it requires no extra miles, no gym membership, and no expensive equipment. In this episode Dr. Daniel Snape — sports scientist, environ...

Patrick Wilson is an exercise physiologist, sports nutrition researcher, and author of The Athlete's Gut. He has spent his career studying how the gut responds to food, fluid, and supplements during exercise — and what actually works versus what the industry wants you to believe. In this episode Patrick breaks down the optimal carbohydrate intake per hour based on the actual dose response research...

Deena Kastor is a three-time Olympian, bronze medalist, former American marathon record holder, Chicago and London marathon champion, and US women's masters marathon record holder at 42 with a time of 2:27. She is one of the most decorated American distance runners of all time. But what made her great was not just her training. It was what she did with the six inches above her shoulders. In this e...

Everyone seems to be chasing 120 grams of carbs per hour at the moment. But the research says that performance actually starts to dip after 100 grams per hour. And the fuelling plan behind two UTMB wins proves it. Paul Booth is a sports nutritionist, exercise physiologist, and lead nutritionist for the Salomon International Team with 26 years in university academia and 92 ultras completed himself....

In this episode we cover what his new paper actually claims about muscle glycogen versus blood glucose, why he now believes 120 grams of carbs per hour works — and why the mechanism is not what anyone thought, the difference between fueling your metabolism and stimulating your brain, why recreational runners may be unknowingly developing pre-diabetes, the central governor theory updated, and his s...

In this episode Matt breaks down exactly why recreational runners become their own ceiling, what he learned training alongside professional runners half his age in Flagstaff, why the 80/20 rule does not need to change as you get older, the carbohydrate debate that is dividing the endurance world right now, and the psychological edge that separates athletes who reach their potential from those who...

Most runners think getting injured comes down to weak glutes, bad form, or worn out shoes. But physiotherapist Brody Sharp says the real reason is almost always something else entirely — and most runners over 40 are missing it completely. In this episode, Brody breaks down the load versus capacity model that explains 90% of running injuries, why strong and weak runners get injured at exactly the s...

Most runners train to improve their lactate threshold. But what if improving it is actually making you slower? In this episode, I sit down with Dr. Peter Tran — sports medicine PhD, 1:14 half marathoner, and co-founder of Athyx — to break down everything runners over 40 need to know about lactate, how to actually use it to guide training, and why most of what you've heard about lactate threshold t...

Jeannie Rice is one of the most remarkable masters runners in the world. In this conversation, she shares how she is still breaking world records in her late 70s, from the 1500m all the way to the marathon, and what really matters if you want to stay fast, healthy, and competitive as you age. We talk about the real reasons behind her longevity in running: consistent mileage, simple training, smart...

Andrea Moore is one of the most accomplished ultra runners in the sport, completing eight races over 200 miles in just eight months in 2025. In this conversation, we explore what it really takes to race at the edge of endurance, from 100 milers to 200+ mile ultras, and how fueling, fat adaptation, recovery, mindset, and durability all change as the distances get longer. Andrea shares how her appro...

Most runners track HRV, but very few actually know how to use it correctly. In this conversation, Dr. Marco Altini explains what HRV can tell you, what it can’t, and how to use it to make better training decisions without becoming a slave to the data. Get your Hume Health Body Pod with up to 50% OFF👉 https://humehealth.com//discount/ENDURANCELAB?redirect=/pages/hume-body-pod&utm_source=youtub...