The Endurance Lab

Can your breathing be the hidden reason running feels harder than it should?
In this episode of The Endurance Lab, I sit down with Dr. Andrew Sellars to explore one of the most overlooked performance limiters in endurance sport: breathing.
Most runners focus on aerobic fitness, mileage, and strength training — but almost nobody trains the muscles that power every breath. Dr. Sellars explains how inefficient breathing can quietly drain performance, why the respiratory system may be the bottleneck for many runners, and how targeted breathing training can improve running economy, VO2 max, and overall endurance.
We talk about how the respiratory muscles affect performance, why breathing may decline with age if left untrained, and how runners can improve it without adding more mileage. We also dive into CO2 tolerance, nasal vs mouth breathing, respiratory muscle training, and how breathing patterns can influence how hard running feels at marathon pace and beyond.

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Get 10% off the Isocapnic BWB to train your respiratory muscles👉 https://shop.isocapnic.com/?sca_ref=10462834.lsRLwaoT7WUNdYIUse code: JusmanSo
Train smarter with Athletica and get 15% off for as long as you stay subscribed!👉 https://athletica.ai/?via=theendurancelabUse code: JUSMAN

Check out all exclusive partner discounts from The Endurance Lab👉 https://theendurancelab.run/exclusive-discounts

In this episode, we cover:
• Why breathing is often ignored in endurance training
• How the respiratory system can limit running performance
• Why breathing can use up a significant amount of energy during hard efforts
• The role of respiratory muscles in fatigue
• Whether breathing gets worse with age
• CO2 tolerance and why it matters for runners
• How respiratory muscle training works
• How breathing affects VO2 max
• Nasal breathing vs mouth breathing for runners
• Why slower, deeper breathing may help running feel easier
• How to integrate breathing training into marathon prep
Chapters
00:00 Intro
00:40 Who Is Dr. Andrew Sellars?2:15 Is Breathing Limiting Your Running?
7:26 How Does Breathing Limit Performance?
10:43 What Actually Limits Your Breathing?
16:08 The Low-Hanging Fruit Most Runners Ignore
18:08 What Is CO₂ Tolerance?
25:45 How To Improve CO₂ Tolerance?
29:41 What is Respiratory Muscle Training?
34:438 How Much Faster Can Breathing Training Make You?
41:37 Can Respiratory Muscle Training Improve VO₂ Max?
47:07 How Would Respiratory Muscle Training Fit Into A Training Plan?
57:013 The Best Breathing Pattern for Marathon Pace
01:02:14 Nasal vs Mouth Breathing

#running #endurancetraining #breathing #vo2max #marathontraining #runningperformance #zonetraining #respiratorytraining #nasalbreathing #mastersrunning #theendurancelab #jusmanso

Can your breathing be the hidden reason running feels harder than it should?
In this episode of The Endurance Lab, I sit down with Dr. Andrew Sellars to explore one of the most overlooked performance limiters in endurance sport: breathing.
Most runners focus on aerobic fitness, mileage, and strength training — but almost nobody trains the muscles that power every breath. Dr. Sellars explains how inefficient breathing can quietly drain performance, why the respiratory system may be the bottleneck for many runners, and how targeted breathing training can improve running economy, VO2 max, and overall endurance.
We talk about how the respiratory muscles affect performance, why breathing may decline with age if left untrained, and how runners can improve it without adding more mileage. We also dive into CO2 tolerance, nasal vs mouth breathing, respiratory muscle training, and how breathing patterns can influence how hard running feels at marathon pace and beyond.

Get the Hume Health Body Pod for up to 50% off👉 https://humehealth.com//discount/ENDURANCELAB?redirect=/pages/hume-body-pod&utm_source=youtube&utm_medium=influencer&utm_campaign=ENDURANCELABUse code: ENDURANCELAB

Get 15% off all NovaaLab red light therapy products👉 https://tidd.ly/46iKcApUse code: EnduranceLab15

Get 10% off the Isocapnic BWB to train your respiratory muscles👉 https://shop.isocapnic.com/?sca_ref=10462834.lsRLwaoT7WUNdYIUse code: JusmanSo
Train smarter with Athletica and get 15% off for as long as you stay subscribed!👉 https://athletica.ai/?via=theendurancelabUse code: JUSMAN

Check out all exclusive partner discounts from The Endurance Lab👉 https://theendurancelab.run/exclusive-discounts

In this episode, we cover:
• Why breathing is often ignored in endurance training
• How the respiratory system can limit running performance
• Why breathing can use up a significant amount of energy during hard efforts
• The role of respiratory muscles in fatigue
• Whether breathing gets worse with age
• CO2 tolerance and why it matters for runners
• How respiratory muscle training works
• How breathing affects VO2 max
• Nasal breathing vs mouth breathing for runners
• Why slower, deeper breathing may help running feel easier
• How to integrate breathing training into marathon prep
Chapters
00:00 Intro
00:35 Who Is Dr. Andrew Sellars?2:15 Is Breathing Limiting Your Running?
7:21 How Does Breathing Limit Performance?
10:38 What Actually Limits Your Breathing?
16:03 The Low-Hanging Fruit Most Runners Ignore
18:03 What Is CO₂ Tolerance?
25:40 How To Improve CO₂ Tolerance?
29:36 What is Respiratory Muscle Training?
34:43 How Much Faster Can Breathing Training Make You?
41:32 Can Respiratory Muscle Training Improve VO₂ Max?
47:02 How Would Respiratory Muscle Training Fit Into A Training Plan?
57:08 The Best Breathing Pattern for Marathon Pace
01:02:09 Nasal vs Mouth Breathing

#running #endurancetraining #breathing #vo2max #marathontraining #runningperformance #zonetraining #respiratorytraining #nasalbreathing #mastersrunning #theendurancelab #jusmanso

Train smarter with Athletica and get 15% off for as long as you stay subscribed!👉 https://athletica.ai/?via=theendurancelabUse code: JUSMAN
📚 Dr. Paul Laursen resources:
Article we spoke about
👉 https://pmc.ncbi.nlm.nih.gov/articles/PMC5117036/

Dr. Paul Laursen website
👉 https://www.paullaursen.com/

Science and Application of High Intensity Interval Training
👉 https://www.amazon.com/Science-Application-Intensity-Interval-Training/dp/1492552127/ref=as_li_ss_tl?ie=UTF8&qid=1543887074&sr=8-2&keywords=science+and+application+of+high+intensity+interval+training&linkCode=sl1&tag=hiit09f-20&linkId=478578fb20c993ebde477fea72dbe1ef

Socials: @hiitscience @athletica_ai

Check out all of the exclusive discounts from Partners of The Endurance Lab
👉 https://theendurancelab.run/exclusive-discounts

Is Zone 2 better than HIIT?
Does endurance training accelerate cardiac aging?
Can improving fat oxidation actually raise your VO₂ max?

In this episode of The Endurance Lab Podcast, I sit down with Dr. Paul Laursen — exercise physiologist, HIIT researcher, elite triathlon coach, and co-founder of Athletica — to unpack one of the most misunderstood topics in endurance training: how aerobic base, fat oxidation, and high-intensity interval training actually work together.
We go beyond the simplistic “Zone 2 vs HIIT” debate and explore how building a strong aerobic foundation improves fat oxidation — even at high intensities — and why that may be one of the hidden drivers of a higher VO₂ max ceiling and the ability to run faster for longer.

🎙 About Dr. Paul Laursen
Dr. Paul Laursen has worked within high-performance sport systems connected to the Australian Institute of Sport and High Performance Sport New Zealand. Academically, he is best known for his research on high-intensity interval training and how manipulating intensity, duration, and recovery drives adaptation. He co-authored High-Intensity Interval Training: Science and Application and co-founded HIIT Science and Athletica.
We also discuss:
• The minimum effective dose of HIIT for midlife athletes
• Why fat oxidation at high intensities matters more than you think
• Carbohydrate periodization and “fuel for the work required”
• HRV-guided training and nervous system readiness
• Whether endurance training accelerates cardiac aging
• The neurological benefits of intensity (yes, lactate feeds the brain)
• The real limitations of ChatGPT-generated training plans
• How AI platforms like Athletica differ from generic AI tools
• The future of AI in endurance coaching

If you’re a masters runner, endurance athlete, or coach trying to balance performance with longevity, this conversation will reshape how you think about training intensity, metabolism, and adaptation.
🔬 Topics Covered
VO₂ max
Fat oxidation
Zone 2 training
HIIT science
Carbohydrate periodization
Metabolic flexibility
HRV and nervous system recovery
Cardiac health in endurance athletes
AI in coaching

Chapters
0:00 Intro
2:05 Zone 2 vs HIIT: A False Dichotomy
5:12 Why Aerobic Base Is the Foundation of Performance
13:10 Lactate, Mitochondria & Lower Lactate at the Same Heart Rate
17:17 Fat Oxidation at High Intensities (The VO₂ Max Connection)
30:10 Definition of High Intensity
37:01 The Minimum Effective Dose of HIIT for Midlife Athletes
39:23 HRV, Nervous System Readiness & When NOT to Train Hard
44:34 Does Endurance Training Accelerate Cardiac Aging?
48:09 Neurological Benefits of HIIT (Why the Brain Loves Lactate)
49:49 Carbohydrate Periodization & Fueling Strategy
53:40 Why ChatGPT Training Plans Fall Short
55:02 How AI Coaching Platforms Actually Work
1:00:54 Can AI Detect Overtraining Better Than Coaches?
1:05:11 The Future of AI in Endurance Coaching

Recovery is a billion-dollar industry, but most athletes are still tired, sore, and unsure what actually works. 15% OFF all NovaaLab Red Light Therapy products👉 https://tidd.ly/46iKcApUse code: EnduranceLab15 Christie Aschwanden's New York Times best-seller:Good to Go: What the Athlete in All of Us Can Learn from the Strange Science of Recovery 👉 https://www.amazon.com/Good-Go-Athlete-Strange-Recovery/dp/039325433XThe Endurance Lab Training Plans (5K, 10K, Half & Full Marathon)👉 http://theendurancelab.run/training-plans Check out all of the exclusive discounts from Partners of The Endurance Lab👉 https://theendurancelab.run/exclusive-discountsIn this episode of The Endurance Lab Podcast, I sit down with Christy Aschwanden — award-winning science journalist and author of the New York Times bestseller Good to Go — to cut through the hype and get brutally practical about the smartest recovery strategy according to science.We talk about what “recovery” really means, why so many popular recovery tools are driven by marketing more than evidence, and how to train hard (especially in midlife) without digging a fatigue hole you can’t climb out of.You’ll also learn: • The difference between overreaching vs. overtraining (and why athletes confuse them) • Why “more training” eventually stops working — and what to do instead • The most overlooked recovery levers after the basics are handled • How placebo and expectation can genuinely change what you feel • How to use HRV without outsourcing your judgment to your wearable • The biggest recovery myths that need to die (including supplements)If you’ve ever felt overwhelmed by recovery advice or unsure whether you’re adapting or just accumulating fatigue, this conversation will give you a clearer framework — and a calmer way to train for the long game.Chapters0:00 Intro1:08 Why Christy wrote Good to Go
3:30 Evidence-based recovery protocol
9:20 Other levers after sleep
18:44 Is volume or intensity harder to recover from?
21:05 Recovery for central nervous system fatigue vs peripheral muscular fatigue
24:22 Overreaching vs overtraining
25:30 Why recovery is more difficult as we age?
27:22 Leveraging the placebo effect to enhance recovery
29:48 HRV in the context of recovery
33:57 Recovery demands of fasted training
35:00 Is muscle soreness adaptation or injury?
41:51 Recovery myth that needs to die#endurance #recovery #running #marathontraining #mastersathlete #sportsscience #training #overtraining #hrv #sleep #athleteperformance #strengthtraining #health #triathlon #cycling #podcast #theendurancelab

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Use code: ENDURANCELAB
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Use code: ELAB10 👉 https://www.moboboard.com/

Running Rewired by Jay Dicharry
👉 https://www.stablebookgroup.com/products/running-rewired?_pos=2&_sid=018450efb&_ss=r

The Endurance Lab Training Plans (5K, 10K, Half & Full Marathon)
👉 http://theendurancelab.run/training-plans

Check out all of the exclusive discounts from Partners of The Endurance Lab
👉 https://theendurancelab.run/exclusive-discounts

Most runners try to “get fitter” with more miles, more intensity, better shoes, more gadgets. Jay Deshari (board-certified sports clinical specialist, PT, biomechanist, researcher, and author of Running Rewired) makes the case that the biggest gains often come from something way less sexy: Better mechanics + better elasticity + better durability.
In this episode, we go deep on why distance running is largely elastic (tendons storing + releasing energy) and how small posture and movement changes can shift running economy by up to 8%, which can beat the benefit of most “super shoe” upgrades.

What we cover
• Why running economy is largely elastic energy transfer (joint to joint)
• The slingshot idea: you must absorb/storing energy first to release it
• Why “land under your body” can be misleading (you often contact slightly in front to load tendons)
• Jay’s lab observation: running economy changed up to 8% just from posture orientation (slight lean forward/back)
• What “form breakdown under fatigue” really costs you (seconds → minutes)
• Why plyometrics are the fastest way to train elastic return (and how most people do them wrong)
• Short ground contact is the point (don’t “hang out” on the ground)
• Avoid ego box jumps (knee-height max)
• Do them fresh, not cooked after a hard session
• A simple strength template for runners (especially 40+)
• 3 quality sets × 4 exercises (done fast, done right)
• 6–8 rep range, rest long enough to actually lift heavy
• Over 40: 2×/week strength often beats another run day for durability + longevity
• The truth about “stability shoes,” pronation/supination, and what actually matters
• Heel striking: not the villain. Where your foot lands relative to your body matters more than what part hits first.

If you’re a masters runner (or just injury-prone), this one is a goldmine.
Chapters
0:00 Intro
8:47 Run 8% faster with less effort
22:40 Muscles vs tendons for running
29:18 Plyometrics
36:38 Strength training
47:47 MOBO Board
1:01:48 Supination, pronation & stability shoes
1:0:31 Heel vs mid vs forefoot strike

#Running #RunningEconomy #RunFaster #Biomechanics #RunningForm #InjuryPrevention #MastersRunning #Plyometrics #StrengthTrainingForRunners #RunningRewired #JayDeshari #EnduranceLab #Zone2 #VO2max #TempoRun #SuperShoes #MarathonTraining #TrailRunning #Mobility #FootStrength