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In this episode of The Endurance Lab, I sit down with Dathan Ritzenhein, a three-time Olympian, former American record holder, World Championship medalist, and head coach of On Athletics Club (OAC), to explore the fundamentals of getting faster—and staying competitive—as we age. Dathan has experienced some of the most influential training philosophies in distance running, working with coaches including Mark Wetmore, Brad Hudson, Alberto Salazar, and the Hansons. Today, he draws on those experiences to coach some of the world's best runners.But what happens when we apply those elite training principles to marathon runners in their 40s, 50s, and 60s? We explore why consistency matters more than chasing mileage, how to balance training volume and intensity, why masters runners shouldn't abandon speed work, and whether popular approaches like Norwegian double-threshold training make sense for recreational marathoners. Dathan also explains how he would structure marathon training for a 50-year-old runner with limited training time who's trying to qualify for Boston, including how to organize workouts, long runs, strength training, and recovery. ➡️ Join The Endurance Lab Inner Circle on Telegram 👉 https://t.me/TheEnduranceLabInnerCircle 🔥 FIND YOUR TRUE ZONE 2 WITH TYMEWEARTymewear Vita Pro measures your breathing in real time to identify your individual physiological thresholds and help you train at the intensity you actually intend to train at. ➡️ Endurance Lab listeners SAVE $100 OFF the Tymewear Pro Training membership Code: E-LABTW26 👉 https://www.tymewear.com/E-LABTW26 ➡️ Listen to my conversation with TimeWear founder Anar Larson: 👉 https://open.spotify.com/episode/5sz25EZjGUHoGSaA38nHwM ➡️ On Athletics Club (OAC) 👉 https://www.on.com/en-fi/explore/athletes/oac-global? Chapters 00:00 Why intensity matters after 40 01:25 Lessons from elite coaches 05:40 Consistency over mileage 11:32 Dathan’s biggest training regrets 16:07 Marathon training for busy runners 20:40 Inside On Athletics Club training 29:30 The long-term approach 36:03 Training for masters runners 43:53 Intensity vs. mileage after 40 47:22 Recovery as you age 50:17 Speed work and strides 55:51 Threshold vs. double threshold 1:00:36 Cross-training for marathoners 1:03:58 Strength training 1:06:09 Lessons from Dathan’s career

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 faster marathon after 40, Marilyn’s progression offers a fascinating look at what it can take to keep improving as a masters runner. Marilyn explains how she structures her training using a base → support → specific approach, how she built toward 50–60 mile weeks, why strides and speed work remain important as we age, and how she incorporates threshold training, marathon-pace workouts and long runs. We also discuss how she balances harder training with injury prevention and recovery. But training was only part of her breakthrough. Marilyn says nutrition was the starting point. She explains how moving toward a whole-food plant-based diet affected how she felt and recovered, what she eats as an endurance athlete, and how she thinks about nutrients such as iron, ferritin, B12 and vitamin D. We also get into strength training for runners over 40, recovery, sleep, HRV, menopause and HRT, and the mindset shift that took Marilyn from believing a sub-3 marathon was impossible to running 2:58 at age 49. Perhaps most importantly, Marilyn doesn’t believe her best running necessarily has to be behind her. At 50, she’s still developing as an athlete and is now chasing an even faster marathon. If you’re a masters runner, midlife runner, marathon runner over 40 or over 50, or you’re simply wondering how to improve your marathon time as you get older, this conversation is a reminder that meaningful improvement can still be possible with consistent training, recovery, nutrition and patience. ➡️ Join The Endurance Lab Inner Circle on Telegram 👉 https://t.me/TheEnduranceLabInnerCircle 🔥 FIND YOUR TRUE ZONE 2 WITH TYMEWEARTymewear Vita Pro measures your breathing in real time to identify your individual physiological thresholds and help you train at the intensity you actually intend to train at. ➡️ Endurance Lab listeners SAVE $100 OFF the Tymewear Pro Training membership Code: E-LABTW26 👉 https://www.tymewear.com/E-LABTW26 ➡️ Listen to my conversation with TimeWear founder Anar Larson: 👉 https://open.spotify.com/episode/5sz25EZjGUHoGSaA38nHwM 🏃 Work with Andrew / Run Elite Coaching: 👉 https://www.andrewsnowcoaching.com CHAPTERS 00:00 From 3:21 to a 2:58 marathon at age 49 00:51 Marilyn’s running journey — and years of getting injured 06:12 How she went from 3:21 to breaking 3 hours 07:00 Training vs nutrition vs mindset: what changed the most? 10:32 What Marilyn eats as a plant-based marathon runner 14:05 How changing her diet affected recovery and performance 22:46 How she trained to run a sub-3 marathon 29:32 Marathon-specific training and marathon-pace workouts 34:18 Why speed still matters for runners over 40 41:54 Balancing speed work, recovery and injury prevention 46:41 Strength training for runners as they get older 54:26 Recovery, HRV, sleep and training fatigue 1:01:43 Why she’s chasing a 2:54 marathon at age 50

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 takes training principles used by elite runners and translates them for recreational athletes. In this conversation, we explore how runners in their 40s, 50s and beyond can apply those principles to marathon training while dealing with limited training time, recovery capacity, work, family and the realities of getting older. We break down Andrew’s base → support → specific approach to marathon training, why he prioritizes training frequency and mileage before harder workouts, how much running you may actually need to reach your marathon potential, the role of strides and hill sprints, marathon-pace training, long runs, nutrition, recovery and race specificity. Andrew also explains why a runner trying to go from a 4-hour marathon toward sub-3 may need to think in terms of years rather than another 12- or 16-week marathon training plan—and why building a much bigger aerobic foundation could ultimately be the key to running your fastest marathon. If you’re trying to figure out how to run a faster marathon, how to break 4 hours, how to run a sub-3:30 marathon, how to run a sub-3 marathon, or how to keep improving as a masters runner, this conversation offers a very different way of thinking about long-term marathon performance. ➡️ Join The Endurance Lab Inner Circle on Telegram 👉 https://t.me/TheEnduranceLabInnerCircle 🔥 FIND YOUR TRUE ZONE 2 WITH TYMEWEARTymewear Vita Pro measures your breathing in real time to identify your individual physiological thresholds and help you train at the intensity you actually intend to train at. ➡️ Endurance Lab listeners SAVE $100 OFF the Tymewear Pro Training membership Code: E-LABTW26 👉 https://www.tymewear.com/E-LABTW26 ➡️ Listen to my conversation with TimeWear founder Anar Larson: 👉 https://open.spotify.com/episode/5sz25EZjGUHoGSaA38nHwM 📘 Andrew Snow’s book — Run Elite: 👉 https://www.runelitebook.com/ 🏃 Work with Andrew / Run Elite Coaching: 👉 https://www.andrewsnowcoaching.com CHAPTERS 00:00 Can you still make a huge marathon breakthrough after 40? 00:30 Why runners plateau — and how to start improving again 05:34 Should you increase mileage or change your training first? 13:08 How much mileage can a runner actually tolerate? 19:18 Autophagy, fasting and recovery for runners 25:20 The best fueling strategy for endurance performance 29:44 Nutrition fundamentals for runners 37:28 The missing ingredient: marathon-specific training 40:00 Inner Circle: The highest-ROI workout for time-crunched runners 44:50 Andrew’s Base → Support → Specific training model 57:55 How much marathon-pace training should you actually do? 1:22:49 Putting it all together: building your marathon training plan #MarathonTraining #RunningAfter40 #Marathon #MastersRunning #Running #Sub3Marathon #BostonMarathon #EnduranceTraining #RunFaster

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 different from today's reading, and what different combinations of HRV and HRV-CV may reveal about recovery, adaptation and accumulated training stress. We also get practical. What should you do when today's HRV is suppressed but you feel great? When should HRV actually cause you to change a planned interval workout? What happens to HRV-CV during a hard training block or taper? And can these metrics help runners recognize when they're adapting well versus drifting toward excessive fatigue? For runners over 40, we also explore an especially interesting question: how do HRV and autonomic stability change as we age? Greg discusses research showing age- and sex-related differences in HRV-CV, what may happen after around age 40, and whether exercise and fitness could help attenuate some of the age-related decline in HRV. In this episode, we cover: what HRV-CV actually measures; HRV vs HRV-CV; why HRV should be compared to your own baseline; whether wearable HRV measurements can be trusted; heat stress and HRV; daily HRV vs seven-day trends; four HRV/HRV-CV training scenarios; when to train hard versus back off; HRV-CV as a marker of adaptation; what happens during overload and tapering; HRV recovery and resilience; how HRV-CV changes with age; autonomic aging; and how Zone 2 and high-intensity training affect HRV. ➡️ Join The Endurance Lab Inner Circle on Telegram 👉 https://t.me/TheEnduranceLabInnerCircle 🔥 FIND YOUR TRUE ZONE 2 WITH TYMEWEARTymewear Vita Pro measures your breathing in real time to identify your individual physiological thresholds and help you train at the intensity you actually intend to train at. ➡️ Endurance Lab listeners SAVE $100 OFF the Tymewear Pro Training membership Code: E-LABTW26 👉 https://www.tymewear.com/E-LABTW26 ➡️ Listen to my conversation with TimeWear founder Anar Larson: 👉 https://open.spotify.com/episode/5sz25EZjGUHoGSaA38nHwM ➡️ Previous Endurance Lab HRV episode with Dr. Marco Altini 👉 https://youtu.be/D6ZPuaMaEgs ➡️ HRV-CV research discussed in the episode: Grosicki et al. — “Heart rate variability coefficient of variation during sleep as a digital biomarker that reflects behavior and varies by age and sex” 👉 https://pubmed.ncbi.nlm.nih.gov/41309064/ Chapters 00:00 Higher HRV vs lower HRV-CV 00:30 Using HRV to guide running training 02:21 What is HRV-CV? 08:57 The science behind HRV-CV 12:03 How new is HRV-CV? 13:48 Dr. Greg Grosicki’s journey to WHOOP 19:31 What is WHOOP? 20:43 Sleep, recovery and strain 27:42 How WHOOP uses recovery data 31:04 Inner Circle: Can you trust HRV from sports watches? 35:15 How heat stress affects HRV 37:06 Daily HRV vs 7-day HRV vs HRV-CV 39:59 Two runners with the same HRV — but very different recovery 44:09 Four HRV + HRV-CV training scenarios 47:47 The HRV-CV warning sign 49:55 How to use HRV to decide whether to train hard 53:28 When good HRV can still be misleading 54:14 Is HRV-CV a measure of adaptation? 55:16 Why low HRV-CV isn't always good 57:19 What happens to HRV-CV during hard training? 58:25 How high is too high for HRV-CV? 1:00:49 What should happen to HRV-CV during a taper? 1:01:30 HRV recovery and resilience 1:03:30 What happens to HRV-CV as we age? 1:05:44 Autonomic aging and HRV 1:08:03 How training can improve HRV and HRV-CV

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 some of the best endurance performances of his life. Sami explains how changing his nutrition increased his measured maximum fat oxidation from roughly 200 to 800 calories per hour, why he describes becoming highly fat-adapted as becoming “bonk proof,” and how he combines a low-carbohydrate lifestyle with strategic carbohydrate intake during hard training and racing. We go deep into fat adaptation, metabolic health, low-carb and ketogenic diets for endurance athletes, carbohydrate periodization, fat oxidation, training after 40 and 50, prediabetes in athletes, recovery, longevity and endurance performance. Sami also breaks down his “live low, race high” approach: eating mostly real foods and minimizing carbohydrates outside training while deliberately using carbohydrates during demanding workouts and competition. Importantly, Sami repeatedly distinguishes his personal N=1 experience as an athlete from established scientific evidence and from his professional work at Virta Health. Low-carbohydrate and ketogenic approaches to endurance performance remain an actively debated area of sports nutrition research, and individual responses can vary. ➡️ Join The Endurance Lab Inner Circle on Telegram 👉 https://t.me/TheEnduranceLabInnerCircle 🔥 FIND YOUR TRUE ZONE 2 WITH TYMEWEARTymewear Vita Pro measures your breathing in real time to identify your individual physiological thresholds and help you train at the intensity you actually intend to train at. ➡️ Endurance Lab listeners SAVE $100 OFF the Tymewear Pro Training membership Code: E-LABTW26 👉 https://www.tymewear.com/E-LABTW26 ➡️ Listen to my conversation with TimeWear founder Anar Larson: 👉 https://open.spotify.com/episode/5sz25EZjGUHoGSaA38nHwM ➡️ Virta Health 👉 https://www.virtahealth.com/ TIMESTAMPS 00:00 Can midlife athletes have metabolic health AND peak performance? 01:22 How did an elite endurance athlete discover he was prediabetic? 09:01 Why are endurance athletes developing prediabetes? 16:29 What did Sami change after discovering he was prediabetic? 22:01 How he increased fat oxidation from ~200 to ~800 calories/hour 25:08 How low-carb does Sami actually go? 37:47 What does Sami eat day to day? 44:18 How does he use carbohydrates during hard training and racing? 52:11 Is Sami really performing better at 50 than when he was younger? 56:27 How has recovery changed with age? 58:20 Why Sami founded Virta Health 1:08:52 Sami’s training and nutrition framework for midlife endurance athletes ABOUT THIS EPISODEThis conversation is for educational and informational purposes only and is not medical or individualized nutrition advice. Speak with an appropriately qualified healthcare professional before making significant dietary changes, particularly if you have diabetes, prediabetes, take glucose-lowering medication, or have another medical condition.

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 neuroplasticity could help aging athletes compensate for physiological decline; why mental fatigue can make an easy run feel hard; and what happens when cognitive training is combined with physical training. Scott also explains how he uses brain endurance training with elite and Olympic athletes, how much training is required, which cognitive tasks may work, and why mental tapering before a race could be one of the easiest performance gains available to runners. If you're a runner over 40 looking for ways to maintain performance as your physiology changes, this conversation offers a fascinating new perspective on what might be limiting you. Dr. Scott Frey is Professor Emeritus of Cognitive Neuroscience and founder of Cerebral Performance. With more than 30 years at the cutting edge of cognitive neuroscience research — and a lifetime in endurance sports — he works with athletes to apply neuroscience and psychology to performance, cognitive resilience and fatigue resistance. Scott has authored more than 100 peer-reviewed publications and books, with his research cited approximately 10,000 times. He has received more than $10 million in federal research funding and has consulted for organizations including the NIH and USA Triathlon. He is also an accomplished endurance athlete, competing in trail running, triathlon and cross-country skiing. ➡️ Join The Endurance Lab Inner Circle on Telegram 👉 https://t.me/TheEnduranceLabInnerCircle 🔥 FIND YOUR TRUE ZONE 2 WITH TYMEWEARTymewear Vita Pro measures your breathing in real time to identify your individual physiological thresholds and help you train at the intensity you actually intend to train at. ➡️ Endurance Lab listeners SAVE $100 OFF the Tymewear Pro Training membership Code: E-LABTW26 👉 https://www.tymewear.com/E-LABTW26 ➡️ Listen to my conversation with TimeWear founder Anar Larson: 👉 https://open.spotify.com/episode/5sz25EZjGUHoGSaA38nHwM ➡️ Scott Frey / Cerebral Performance: 👉 https://cerebralperformance.com/ Chapters: 0:00 Can Brain Training Make You Faster? 4:34 How the Brain Controls Performance 10:08 Age, Experience and Endurance 16:40 Scott’s Journey Into Brain Science 23:22 What Is Brain Endurance Training? 28:58 How Much Can Performance Improve? 41:35 Mental Tapering Before Racing 46:36 How to Start Brain Training 1:01:27 Mental Fatigue and Running 1:13:31 Exercise and the Aging Brain

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, Relative Energy Deficiency in Sport (RED-S), athlete fueling, and eating disorder recovery. Rebecca explains why RED-S is not just a problem affecting young female athletes, why masters athletes are often overlooked, and how trying to lose weight while increasing training volume can leave athletes stuck in a cycle of poor recovery, declining performance, and increased injury risk. Rebecca shares her own experience as a masters athlete, mother, and endurance enthusiast, explaining why so many recreational athletes fall into the trap of trying to do more training while eating less. Rebecca McConville works with athletes ranging from recreational endurance athletes to elite competitors, helping them understand the connection between nutrition, performance, health, and long-term athletic development. ➡️ Join The Endurance Lab Inner Circle on Telegram 👉 https://t.me/TheEnduranceLabInnerCircle 🔥 FIND YOUR TRUE ZONE 2 WITH TYMEWEARTymewear Vita Pro measures your breathing in real time to identify your individual physiological thresholds and help you train at the intensity you actually intend to train at. ➡️ Endurance Lab listeners SAVE $100 OFF the Tymewear Pro Training membership Code: E-LABTW26 👉 https://www.tymewear.com/E-LABTW26 ➡️ Listen to my conversation with TimeWear founder Anar Larson: 👉 https://open.spotify.com/episode/5sz25EZjGUHoGSaA38nHwM ➡️ Rebecca’s Website: 👉 https://beccamcconville.com ➡️ Rebecca’s book: Finding Your Sweet Spot: How to Avoid RED-S and Fuel Your Athletic Performance 👉 https://www.amazon.com/dp/1091089051?lv=shuf&channelId=500&plpRedirect=mhFallback Chapters 00:00 The hidden problem affecting masters athletes 02:30 What is low energy availability and RED-S? 04:54 Why calories are not the whole story 06:44 Are older athletes at risk of RED-S? 08:26 How athletes accidentally fall into underfueling 11:10 The long-term health consequences of chronic underfueling 13:11 Why aging can hide RED-S symptoms 14:20 Early warning signs you should not ignore 17:35 Digestion, sleep, immunity and RED-S symptoms 18:49 Can HRV and resting heart rate reveal underfueling? 20:46 Can you have low energy availability without symptoms? 21:52 Is fasted training actually beneficial? 23:28 Fat oxidation vs endurance performance 26:58 Keto diets, carbohydrates and RED-S risk 31:33 Losing body fat without destroying performance 35:03 How much energy do endurance athletes actually need? 36:27 How to recover from RED-S 39:07 Why carbohydrates matter during recovery 40:30 How long does RED-S recovery take? 44:37 Can you keep training while recovering from RED-S? 47:44 Finding help and working with RED-S specialists 50:41 The biggest nutrition mistake masters athletes make 51:35 The one nutrition change athletes should make today 52:24 What does endurance mean to Rebecca McConville?

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” actually means, why fat adaptation is a spectrum rather than an on/off switch, and whether a ketogenic or low-carbohydrate diet is really necessary to increase fat oxidation. Matt explains how endurance training, mitochondrial capacity, carbohydrate availability and diet interact to determine how much fat you can oxidize during exercise. We also discuss how quickly fat oxidation can change, why becoming better at burning fat doesn’t automatically improve performance, and how going too far with carbohydrate restriction could reduce your metabolic flexibility and ability to perform at higher intensities. Most importantly, we get practical. Matt explains how recreational runners training around 5–7 hours per week can use carbohydrate periodization, low-carbohydrate meals and selected fasted training sessions to improve fat oxidation — while strategically using carbohydrates around hard training and racing. We also dive into Matt’s research on keto-adapted athletes and carbohydrate supplementation, including why strategically introducing carbohydrate around exercise may improve performance without necessarily undoing the adaptations developed through a low-carbohydrate diet. If you’re interested in becoming a more fat-adapted runner, ketogenic diets for endurance athletes, metabolic flexibility, fasted training, carbohydrate periodization, fat oxidation, endurance nutrition or how to fuel your running after 40, this conversation brings the science together without taking a dogmatic “high-carb vs keto” position. ➡️ Join The Endurance Lab Inner Circle on Telegram 👉 https://t.me/TheEnduranceLabInnerCircle 🔥 FIND YOUR TRUE ZONE 2 WITH TYMEWEAR Tymewear Vita Pro measures your breathing in real time to identify your individual physiological thresholds and help you train at the intensity you actually intend to train at. ➡️ Endurance Lab listeners SAVE $100 OFF the Tymewear Pro Training membership Code: E-LABTW26 👉 https://www.tymewear.com/E-LABTW26 ➡️ Listen to my conversation with TimeWear founder Anar Larson: 👉 https://open.spotify.com/episode/5sz25EZjGUHoGSaA38nHwM CHAPTERS 0:00 How to Become Fat Adapted 1:23 Do You Need Keto? 4:21 What Fat Adaptation Means 5:52 Mitochondria and Fat Oxidation 7:57 Fat Adaptation Is a Spectrum 10:18 Do You Need Ketosis? 15:31 Strategic Carbohydrate Use 20:17 Do Carbs Undo Fat Adaptation? 23:56 Long-Term Keto Adaptation 30:59 Fueling Long Runs on Keto 35:39 How Quickly Can You Adapt? 40:01 Diet vs Endurance Training 42:36 Fat Adaptation on 5–6 Hours 45:04 Metabolic Flexibility 49:11 Maximizing Fat AND Carbs 54:58 Train Low, Race High 57:17 Matt’s Carbohydrate Study 1:00:20 When to Use Carbohydrates 1:07:10 Keto vs High Carb: Who Wins? 1:12:29 Does Fasted Training Work? 1:16:19 Practical Fat-Adaptation Strategy 1:18:36 Why a Hybrid Approach Works 1:23:31 What Endurance Means to Matt LINKS & RESEARCH Matt Carpenter — University of Northampton: https://www.northampton.ac.uk/directories/people/matt-carpenter/ Matt Carpenter — Research Profile / Publications: https://pure.northampton.ac.uk/en/persons/matt-carpenter/ Matt Carpenter — Instagram @mattendurancescientist Carpenter, Brouner & Spendiff (2024) — Carbohydrate Supplementation Improves Ultra-Endurance Performance in a Keto-Adapted Individual: https://hrcak.srce.hr/ojs/index.php/kinesiology/article/view/27167 Volek et al. (2016) — Metabolic Characteristics of Keto-Adapted Ultra-Endurance Runners: https://pubmed.ncbi.nlm.nih.gov/26892521/

➡️ 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, and eventually broke multiple world records in his 40s. His achievements include: 🏃 100 km world record — 6:05:35 🏃 100 mile world record — 10:51:39 🏃 6-hour world record — 98.496 km 🏃 12-hour world record — 177.410 km 🏃 24-hour world record — 319.614 km He became the first runner to break the 11-hour barrier for 100 miles, and during that same race he also set the 12-hour world record. What makes Alexander’s story even more remarkable is that he did not begin running seriously until around age 32. Before that, after finishing his earlier sporting career in kayaking, he says his lifestyle became unhealthy — alcohol, cigarettes, poor food choices, and his body weight climbed to around 100 kg. Running initially started as a way to lose weight. Then he discovered ultra-running. A few years later, he was winning major races. By his early 40s, he was breaking world records. Alexander explains how his training evolved from roughly 60–80 km per week to peak weeks around 250–300 km, why long runs of 30–50 km became the foundation of his training, how he uses interval sessions to maintain speed as he gets older, and why recovery has become increasingly important in his mid-40s. We also discuss what runners over 40 can learn from his progression, why starting later does not necessarily mean your best running years are behind you, and how consistency, training variety, mileage and simply loving the process have shaped his career. For masters runners, recreational runners, marathoners and ultrarunners, Alexander’s journey is a powerful example of how dramatically running performance can change even when you start later in life. ➡️ Save $100 on Tymewear Pro Training Membership Code: E-LABTW26 👉 https://www.tymewear.com/E-LABTW26 ➡️ Listen to my conversation with TimeWear founder Anar Larson: 👉 https://open.spotify.com/episode/5sz25EZjGUHoGSaA38nHwM 00:00 From 100 kg to running 1:35 Alexander’s world records 2:50 His life before running 5:43 From weight loss to world records 7:18 Did he ever expect to become elite? 10:01 Strength training and cross-training 11:03 Starting running in his 30s 12:52 Can runners still improve after 40? 16:54 How his training volume evolved 20:56 How his speed training changed with age 24:16 Mileage vs structured training 25:29 When he reached his peak 28:46 How runners over 40 can still improve 29:39 What recreational runners can learn from him 31:21 Heart rate vs pace 33:08 What to do when your best years feel behind you

➡️ 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 breakthrough in endurance fueling. We discuss: • Why lactate is no longer considered the "bad guy" • How exogenous lactate works inside the body • Whether lactate is actually a preferred fuel over glucose • How it compares with ketones • Whether it could improve endurance performance • Possible effects on the brain, recovery and fatigue • Why the science is still in its early stages • What athletes should realistically expect today If you've been hearing rumours about pro cycling teams using lactate during races, this episode explains the science directly from one of the researchers developing the technology. ➡️ Save $100 on Tymewear Pro Training Membership Code: E-LABTW26 👉 https://www.tymewear.com/E-LABTW26 ➡️ Listen to my conversation with TimeWear founder Anar Larson: 👉 https://open.spotify.com/episode/5sz25EZjGUHoGSaA38nHwM 🏃 5K, 10K, Half & Full Marathon Training Plans 👉 https://theendurancelab.run/training-plans 🎓 Exclusive Discounts & Resources 👉 https://theendurancelab.run/exclusive-discounts Exolactate Learn more about Exolactate and FLF: https://flf.shop Research website: https://exolactate.com 00:00 Why lactate may be the body's preferred fuel 01:00 Why elite athletes are suddenly interested in exogenous lactate 05:11 Is lactate where ketones were a few years ago? 08:08 How Aitor became interested in lactate research 10:17 How carbohydrates become lactate 12:14 Which organs actually use lactate? 14:12 Why lactate gets "VIP treatment" in the body 20:40 Is lactate a by-product of carbohydrate oxidation? 22:05 Where lactate fits among carbohydrates, fat and ketones 25:20 What happens after you drink exogenous lactate? 29:43 Is exogenous lactate different from natural lactate? 31:16 What's actually inside Exolactate? 38:04 Is exogenous lactate safe? 40:37 Does exogenous lactate bypass the cost of producing lactate? 42:26 Lactate, buffering and fatigue 45:40 Can lactate break through the carbohydrate ceiling? 47:25 Does lactate make carbohydrates work better? 49:51 Will lactate replace carbohydrates? 50:36 Lactate vs ketones 52:25 Training vs racing with exogenous lactate 55:07 Which athletes benefit the most? 57:38 Could lactate reduce central fatigue? 58:25 Recovery benefits 59:41 Why creating an exogenous lactate gel was so difficult 1:05:00 How much lactate do athletes actually need? 1:08:42 The biggest takeaway about exogenous lactate 1:09:33 What endurance means to Aitor

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 Trainer at Texas State University. He is the Director of the Heat Emergency Assessment and Treatment (H.E.A.T) Lab in the Department of Health and Human Performance. His research expertise includes the causes, treatments, and prevention of exertional heat illnesses with a specific emphasis on exercise-associated muscle cramping and exertional heatstroke. He has published over 75 peer-reviewed manuscripts and given over 120 presentations on exertional heat illnesses. He has Chaired or co-authored 5 different official heat illness position statements including the 2021 NATA Roundtable on the Prehospital Care of Exertional Heatstroke and the 2015 NATA Position Statement on Exertional Heat Illness. He is a Fellow of the NATA, Associate Editor for the Journal of Athletic Training, member of the Korey Stringer Institute’s Medical and Science Advisory Board, and consultant to schools, hospitals, Universities, and companies for his expertise in heat-related illness. ➡️ Dr. Kevin Miller: For consultancy-related assistance on heat or muscle cramping, you can contact Dr. Miller at [email protected]. ➡️ Save $100 on Tymewear Pro Training MembershipCode: E-LABTW26 👉 https://www.tymewear.com/E-LABTW26 ➡️ Listen to my conversation with TimeWear founder Anar Larson: 👉 https://open.spotify.com/episode/5sz25EZjGUHoGSaA38nHwM 🏃 5K, 10K, Half & Full Marathon Training Plans 👉 https://theendurancelab.run/training-plans 🎓 Exclusive Discounts & Resources 👉 https://theendurancelab.run/exclusive-discounts We also discuss: • What actually causes muscle cramps • Why stretching works immediately • Why dehydration isn't the whole story • Whether electrolytes actually matter • Bananas, pickle juice, tonic water and salt tablets • Heat vs cold environments • Why elite athletes still cramp • How to prevent cramps • What to do when a cramp strikes • The surprising science behind vinegar and pickle juice • Practical advice every endurance athlete should know 00:00 Introduction 02:21 What actually causes muscle cramps? 06:02 Nervous system vs muscle — where do cramps start? 09:02 Why Kevin started researching muscle cramps 12:00 Why cramps become so painful 14:59 The Multifactorial Theory of cramping 18:07 Does dehydration actually cause cramps? 24:37 Do electrolytes matter? 31:00 Why stretching stops cramps 32:35 Hydration vs cramp prevention 40:45 Exercise cramps vs night cramps 43:21 Do bananas prevent cramps? 46:04 Does pickle juice really work? 53:19 Coconut water and muscle cramps 57:53 Heat, cold and cramping 01:02:30 How to prevent muscle cramps 01:08:48 Does conditioning reduce cramping? 01:11:08 Best way to treat a cramp 01:17:43 Recovery after exercise 01:21:13 The biggest takeaway 01:22:33 Biggest mistakes athletes make 01:25:07 What endurance means to Dr. Kevin Miller #MuscleCramps #Endurance #Running #Triathlon #SportsScience #ExerciseScience #Hydration #Electrolytes #Marathon #UltraRunning #Cycling #Performance #EnduranceLab

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, whether it actually improves sea-level performance, the physiological adaptations behind altitude training, and whether an altitude generator is worth the investment for recreational runners and cyclists. If you've reached a plateau despite consistent training, this episode explains why hypoxic training may be one of the few remaining tools capable of producing meaningful physiological adaptations that traditional training cannot. 🫁 Save $100 on Tymewear Pro Training Membership Code: E-LABTW26 👉 https://www.tymewear.com/E-LABTW26 🫁 10% Off ISOCapnic BWB Device Code: JusmanSo 👉 https://shop.isocapnic.com?sca_ref=10462834.lsRLwaoT7WUNdYI 🏃 5K, 10K, Half & Full Marathon Training Plans 👉 https://theendurancelab.run/training-plans 🎓 Exclusive Discounts & Resources 👉 https://theendurancelab.run/exclusive-discounts 🫁 Customised hypoxic and heat training programs by Dr. Barney Wainwright and his team at Leeds Beckett University Health and Performance Hub: https://www.leedsbeckett.ac.uk/carnegie-school-of-sport/health-and-performance-hub/ In this episode you'll learn: • How hypoxic training improves endurance performance • The difference between central and peripheral adaptations • Why elite athletes use altitude training • Whether altitude tents, masks and generators actually work • Heat training vs hypoxic training • How to choose the right hypoxic training method • Whether a $3,000 altitude generator is actually worth the investment Connect with The Endurance Lab 📩 Email: [email protected] 00:00 Why hypoxic training isn't cheap—but can be worth it 00:53 Can low oxygen training actually make you faster? 03:48 What is hypoxic (altitude) training? 06:02 Different types of altitude training explained 07:18 Natural altitude vs simulated altitude 09:43 What counts as moderate and high altitude? 11:32 What actually happens inside your body at altitude? 15:00 Acute vs long-term adaptations to hypoxia 21:35 Red blood cells, EPO and oxygen delivery 24:05 Muscle adaptations beyond red blood cells 30:17 Does altitude training improve sea-level performance? 41:39 Why altitude generators are so practical 46:56 Biggest misconceptions about hypoxic training 52:17 Can smartwatches accurately measure SpO₂? 54:11 Heat training vs hypoxic training 1:06:00 Best hypoxic training equipment for recreational athletes 1:11:46 Breathing devices, respiratory muscle training & breath holds 1:17:43 Blood flow restriction training 1:22:21 What's the best investment for endurance performance? 1:25:01 Altitude generator or carbon wheels? 1:26:46 What endurance means to Dr. Barney Wainwright

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 Endurance Lab, I sit down with ketone researcher Dr. Jonathan Little to break down the surprising differences between nutritional ketosis and exogenous ketones — and why ketone supplements may actually make more sense for high-carb endurance athletes than runners following a ketogenic diet. We discuss: - Why taking ketone supplements is NOT the same as being in ketosis - The difference between endogenous ketosis and exogenous ketones - Why ketone supplements raise insulin and suppress fat burning - Why keto-adapted runners may get less benefit from ketone supplements - Whether ketone esters can actually improve marathon performance - The truth about ketones as the “fourth macronutrient” - Ketone supplements vs carbohydrates for endurance performance - Whether high-carb runners should consider ketone esters - The potential role of ketones in recovery, glycogen replenishment, inflammation, sleep, and brain health Jonathan Little has spent over a decade researching ketones, ketogenic diets, metabolic health, insulin resistance, and exercise physiology. His work helps separate the hype around exogenous ketones from what the science actually shows. 00:00 Ketone Research Background 01:48 Endogenous vs Exogenous Ketosis 07:02 Why Supplements Reduce Fat Burning 08:14 Metabolic Health Benefits Compared 10:48 Keto Weight Loss Explained 13:48 Keto vs High Carb For Runners 20:52 Sports Gels Metabolic Risk 27:10 Types of Ketone Supplements 33:18 D vs L BHB Differences 36:07 BHB Thresholds and Tradeoffs 38:51 Acute vs Sustained Ketone Dosing 40:21 Ketogenic Marathoner Scenario 46:11 High Carb Athlete Reality Check 48:43 Recovery and Adaptation Focus 50:53 Why Performance Can Drop 53:46 Practical Advice for Runners 54:52 Recovery Benefits Breakdown 01:00:02 Brain and Inflammation Potential 01:08:46 Metabolic Health Takeaways 01:09:56 Defining Endurance Closing

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, reduce injury risk, and help you run faster using the same fitness. We cover arm swing, cadence, heel striking, midfoot striking, overstriding, ground contact time, vertical oscillation, running economy, biomechanics, force production, and the simple cues that helped me immediately feel lighter and more effortless while running. ► The Core Program of Cues - https://www.tbrunner.com/membership/ ► Code: ELP (for 25% off your first month) Connect with Paul Mackinnon ► Website: https://www.tbrunner.com/ ► YouTube: https://www.youtube.com/c/thebalancedrunner ► Instagram: https://www.instagram.com/thebalancedrunner/?hl=en In this episode* Why running form matters * How biomechanics affect running economy * Why physics determines efficient running * The biggest running form mistakes * Why most runners overstride * Heel strike vs midfoot strike * Does cadence really matter? * Ground contact time explained * Vertical oscillation explained * Why arm swing is the most misunderstood part of running * The connection between arm swing and knee drive * Why elite runners move differently * Running efficiency vs running economy * How better running mechanics can reduce injuries * The easiest running form cue anyone can implement today Timestamps 00:00 Why arm swing is so important 01:12 My running form breakthrough after working with Paul 02:42 Why running form actually matters 04:01 Does better running form improve running economy? 06:20 How to change your running technique safely 09:17 Structural asymmetry vs movement asymmetry 12:44 The biggest running form mistakes 16:32 Running form and injury risk 18:20 Why self-awareness is the first step 22:13 Why arm swing changes everything 25:58 The real purpose of your arms while running 29:27 Why lifting—not pushing—is the secret 32:41 Perfect arm swing explained 35:03 The truth about vertical oscillation 42:13 Heel strike vs midfoot strike 48:15 The biggest myth about cadence 53:31 Ground contact time explained 59:40 Why your torso should stay quiet 1:04:34 Why elite runners use their glutes 1:13:10 What happens during a running form analysis 1:19:49 The easiest running cue to improve immediately

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 Tymewear Pro Training Membership Code: E-LABTW26 👉 https://www.tymewear.com/E-LABTW26 🫁 10% off Isocapnic BWB DeviceCode: JusmanSo 👉 https://shop.isocapnic.com?sca_ref=10462834.lsRLwaoT7WUNdYI 🏃 5K, 10K, Half & Full Marathon Training Plans 👉 https://theendurancelab.run/training-plans 🎓 Exclusive Discounts & Resources👉 https://theendurancelab.run/exclusive-discounts In this episode: • Why many runners are not really in Zone 2 • Why heart rate can drift without your physiology changing • Why ventilation may be a better marker of intensity • How VT1 and VT2 define your real training zones • Why fat oxidation matters for endurance performance • How to improve durability and delay fatigue • Why breathing muscles can be trained • How Tymewear Vital Pro measures ventilation in real time Connect with The Endurance Lab: 📩 Email: [email protected] Chapters: 00:00 Are You Really Zone 2? 03:00 What Zone 2 Means 06:02 Ventilation vs Lactate 10:32 Why Heart Rate Misleads 15:20 Measuring Physiological State 22:25 Why Generic Zones Fail 26:25 Power Needs Physiology 29:11 Zone 3 Stagnation 30:17 Anar’s Background 34:00 Ventilation as Ground Truth 37:39 Ventilation vs Heart Rate 39:41 How Tymewear Measures Breathing 45:26 Finding VT1 and VT2 50:59 Where Ventilation Fails 56:04 Breathing Rate vs Tidal Volume 58:36 Tymewear Vital Pro 1:03:57 Training in Heat 1:07:49 What Is Durability? 1:11:28 Other Real-Time Tools 1:13:48 Stress and Breathing 1:14:54 Training Breathing Muscles 1:17:13 ISOCapnic BWB #runningover40 #marathontraining #zonetwotraining #heartratetraining #endurancetraining