Run Long Run Healthy

Heart rate, pace, and power are the metrics every endurance athlete tracks, but they're all proxies for what's really happening inside the body. In this episode, Brady sits down with Arnar Larusson, co-founder of Tymewear and the mind behind the VitalPro device. Arnar makes the case for ventilation as a more direct, more stable window into internal workload and fitness. Custom insoles made with supershoe foam: visit kilarun.com and use code “RLRH” to get $50 off your first order.

Carb loading before a marathon is one of the most "accepted" rituals in distance running, but does it actually improve race performance? In this episode of Run Long Run Healthy, Thomas Watson and Brady Holmer break down a brand-new meta-analysis that finally asks the question nobody had rigorously tested: does carbohydrate loading work if you're already fueling properly during the race? If you've ever wondered whether you really need to stuff yourself with pasta the night before your marathon, this episode has the answer. 00:00 Introduction: Revisiting the Carb Loading Orthodoxy 00:32 What Is Carbohydrate Loading? (Glycogen Science Explained) 03:27 The Original Protocol & Old-School Traditions (Pasta Parties, Grandma's Marathon) 06:10 The New Meta-Analysis: Does Carb Loading Even Work? 08:00 Placebo, "Nocebo," and the Study's Limitations 13:32 Sponsor: Kila Insoles 15:55 What This Means for Everyday Marathon Runners 19:49 Brady's Recommended Carb Loading Protocol 28:19 Race-Day Fueling & the Breakfast Debate 32:30 Final Takeaways: Do You Actually Need to Carb Load?

Wahoo Fitness spent 15–20 years becoming the data leader in indoor cycling and now they're bringing that same obsession with precision to running. In this episode of Run Long Run Healthy, Thomas Watson and Brady Holmer sit down with Joe Justice and Mac Cassin of Wahoo Fitness to break down the KICKR RUN treadmill, a machine they rebuilt from the ground up instead of just copying what already existed. We get into why cycling data (power, cadence, FTP) doesn't translate cleanly to running, how Wahoo is tackling grade-adjusted pace, vertical oscillation, and ground contact time, and why "durability" and physiological resilience are the next frontier in runner data. Joe and Mac also walk through the three non-negotiable design principles behind KICKR RUN (run feel, speed/acceleration control, and simplified controls), the treadmill's 4-minute-mile top speed, Run-Free adaptive pacing mode, terrain mode, and the Bluetooth headwind fan. Plus, how thermoregulation changes when you take a run indoors. Chapters: 0:00 Introduction: Wahoo enters the treadmill game 1:04 Why Wahoo built a treadmill from scratch 2:03 The cycling-to-running data gap 4:00 GPS accuracy & grade-adjusted pace 6:20 Individualized metrics vs. population averages 7:55 Physiological durability & resilience scoring 10:24 Sponsored by Kila custom insoles 12:37 Turning treadmill data into actionable feedback 14:43 Inside KICKR RUN's 6–7 year development story 16:39 The 3 non-negotiable design principles 19:35 Why treadmill speed limits held runners back 21:24 Run-Free mode, terrain mode & the headwind fan 26:16 The case for precision in indoor training 27:33 Reframing the treadmill as a tool, not a fallback 29:58 Thermoregulation, sweat & heat adaptation indoors 33:57 Reducing mental load to stay motivated 38:13 The next 10 years: AI, wearables & training data 44:07 Explaining Wahoo's 3DP/4DP performance models 50:09 Will AI ever replace a running coach? 55:42 Integrating cycling into your run training 58:53 Where to demo the Wahoo KICKR RUN Custom insoles made with supershoe foam: visit kilarun.com and use code “RLRH” to get $50 off your first order. Check out the KICKR RUN Treadmill: https://www.wahoofitness.com/devices/running/treadmills/kickr-run-buy

Could the best runners of the 1960s have beaten the sub 2-hr marathon if they had 2026 level sports science, gear, and training protocols? That’s what Thomas is looking to answer today - and why our understanding of Marginal Gains is, at times, flawed. Chapters: 00:00 Could old-school runners have broken 2 hours? 01:31 Derek Clayton's old-school gear, diet & training 02:32 Stacking modern marginal gains onto Derek 05:42 Were old-school runners just tougher? 06:36 Origin of "marginal gains": Team Sky 07:30 The Team Sky doping controversy 08:29 Debunking the marginal gains myth 11:20 Ceiling effects and the Atomic Habits graph 13:04 Marginal gains = avoiding bad outcomes too 14:00 Back to Derek: what the real data says 18:05 Why Derek would still trail today's best 19:45 Verdict, and a message to Derek Clayton 22:03 Two real takeaways for your own training Join Marathon Handbook’s RunClub for access to our members-only podcast, training plans, community rooms, merch and more: https://marathonhandbook.com/runclub Shop Marathon Handbook merch: https://store.marathonhandbook.com

We do blood testing with RYTHM: Rythm is offering our listeners 15% off your first month and free shipping at https://RYTHM.HEALTH/RLRH Brought to you by ProBio Nutrition - your all-in-one daily supplement for runners. Get 40% off with code RLRH (and an additional 10% off + free shipping with a subscription) ➡️https://bit.ly/ProBioRLRH Brady and Thomas break down the new viewpoint paper on endurance whose co-authors include Michael Joyner: https://journals.physiology.org/doi/pdf/10.1152/japplphysiol.00343.20250:00 Introduction – The 4 Components of Fatigue Resistance0:39 What Is Durability? (The Joiner Model Revisited)4:00 Sponsor: ProBio Nutrition5:12 How to Use These 4 Terms to Find Your Weaknesses5:57 #1: Durability – Holding Your Physiology Together at Constant Pace8:32 How to Train for Better Durability11:30 #2: Fatiguability – Performance Loss Under Variable Intensity14:38 Sponsor: RYTHM Health (At-Home Blood Testing)17:11 #3: Repeatability – Can You Hit the Same Splits Every Interval?18:36 How to Train for Better Repeatability22:37 #4: Resilience – Performing Under Unexpected Conditions23:55 Amby Burfoot's 1968 Boston Win: A Case Study in Resilience26:47 How to Train for Resilience (Steve Magnus's Secret Tactic)28:31 The Danger of Being Over-Optimized on Race Day29:52 Thomas & Brady's Own Strengths and Weaknesses35:45 Resilience: The Last Unmeasurable Variable in Endurance Sport37:04 Wrap-Up