Science Of Ultra | Ultra Marathon And Trail Running Expertise | World Leading Endurance Science And Coaching

Ultra marathon running physiology brought to you by the world’s leading scientists, coaches, and athletes. Science Of Ultra host, Dr. Shawn Bearden, brings you interviews and more to deliver everything you want to know about all facets of training, nutrition, hydration, environment, psychology, gear, and much more. Become your ultra best!
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Science Of Ultra | Ultra Marathon And Trail Running Expertise | World Leading Endurance Science And Coaching



All Episodes
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Sep 13, 2016

Findings from recent research on recovery practices and their effectiveness for ultra marathon finishers.

Aug 30, 2016

The myth of adrenal fatigue.

Aug 16, 2016

Western States champion (2015), Magdalena Boulet, joins me for an amazing episode. Learn all the ins and outs of her training, racing approaches, nutrition strategies, and much more!

Aug 2, 2016

Roundtable discussion with three coaches (Paul Lind, Andrew Simmons, Ty Draney) recorded on location, including audience questions.

Jul 19, 2016

Ian Torrence has complete nearly 200 ultra distance events and has won approximately 25% of them. He has important advice to give regarding longevity in the sport and approaches to DNFing that you need to hear if you want to be successful in this sport for years to come.

Jul 5, 2016

You are an endurance runner. So, what's the point in doing high intensity interval training (HIIT)? Whether you are new to endurance running or a seasoned veteran, you will benefit from HIIT. We explore how, what, when, and why in this episode.

Jun 21, 2016

Learn how to prepare for performance in the heat and how heat acclimation can actually improve your performance in moderate temperatures.

Jun 7, 2016

Ben Levine, MD is among the legends of exercise cardiology and altitude physiology in sport performance. It is an honor to have him join the Ultra Clan for this amazing interview, packed with heaps of evidence-based, applicable, relevant, and actionable knowledge.

May 24, 2016

Today, I shine the spotlight on Mathew Laye, PhD. He is a scientist, coach, and athlete. As winner of the Rocky Raccoon 100 miler, along with his scientific and coaching background, he brings a rare mix of all three areas of expertise in ultra marathon training and racing to the show.

May 10, 2016

A double episode. Interviews with cardiologists Larry Creswell M.D. and Aaron Baggish M.D. They are at the forefront of heart health in endurance athletes. Is ultra marathon running okay for your heart? Listen and learn.

Apr 26, 2016

My guest today has had a life of endurance, persistence, adventure and exploration that we can all learn from. My guest is Terri Schneider. She was a professional triathlete for nine years, has raced multi-day eco-adventures around the planet, and is an ultra marathon veteran. We explore her life of endurance pursuits through the lens of her recent book, Dirty Inspirations: Lessons from the trenches of extreme endurance sports.

Apr 12, 2016

This week, we explore the ins and outs of economical running. Learn what you can do to improve yours and to what extent it will make a difference in your performance.

Mar 29, 2016

My guest today is Michael Gervais, PhD. He has been described as an industry visionary. Dr. Gervais is a licensed psychologist who focuses most of his time on people at the "top of their game", including the NFL's Seattle Seahawks, NBA players, Olympians, military personnel and corporate leaders. While spending years in the trenches of high-stakes circumstances, he has developed clarity for the tools that allow people to pursue their potential.

Mar 15, 2016

My guest today is John VonHof. He literally wrote the book on foot care for the athlete, Fixing Your Feet. You can learn more from him on his website, <link><link>

Today we dig into all the essential components of good foot care, from shoe fitting to blister care. We wrap up by defining the essential features of a good minimalist foot care kit for your next run or adventure.

Mar 1, 2016

My guest this week is Max King. He won the 2011 World Mountain Running Championships and the 2014 IAU 100 km World Championship. He’s won numerous national titles at distances ranging from half marathons to ultra marathons and he was named U.S. national mountain runner of the year in 2011. He is a back-to-back winner of the Warrior Dash world championship, winning in 2014 and 2015. Also, in 2014 he tackled his first 100 mile race, the legendary and extremely competitive Western States 100 mile Endurance Run where he finished 4th.

Feb 16, 2016

An incredible episode on psychological fatigue. Is fatigue in ultra endurance performance mostly in your mind? What can you do to stay psychologically motivated to keep going? Listen and learn on today's episode with the pioneering experts on this topic.

Feb 2, 2016
My guest today is Daniel Lieberman, PhD
Dr. Lieberman is Professor and Chair of the Department of Human Evolutionary Biology, and the Edwin M. Lerner II Professor of Biological Sciences at Harvard University. He was educated at Harvard and Cambridge. He studies how and why the human body is the way it is, and the relevance of human evolution to contemporary health. His major research foci include the evolution of long distance walking and running abilities as well as the effects of shoes on locomotor biomechanics and injury; he also studies the evolution of the highly unusual human head. His work has been funded by the National Institutes of Health, the National Science Foundation, and many other groups and foundations. He has ongoing fieldwork projects in Kenya and Mexico. In addition to over 130 peer-reviewed research articles, he’s published several books including "The Evolution of the Human Head (Harvard University Press, 2011), and “The Story of the Human Body” (Pantheon, 2013). If you’ve read the book “Born to Run”, then you’re already familiar with his work because that title was actually the title of a cover in the journal Nature that featured his research well before the book of the same title; and my guest is a major figure in the book itself.
In this episode, we explore the evolution of running, the biomechanics of barefoot running, and what shoe cushioning is and does for (and to) us. We make the distinction among barefoot, minimalist, and cushioned shoes and learn about the interesting effect of barefoot running, and possibly minimalist shoe running, on normalizing foot arches.
As always, we wrap up with some actionable answers to fundamental questions in barefoot running when I ask Dr. Lieberman,
  1. What are the most common misconceptions you see in the running community with respect to barefoot vs shod running?
  2. Based on all your research, are their compelling reasons to consider barefoot or minimalist running from an endurance performance standpoint?
  3. Is there any reason to think that someone running ultra marathons would perform better or be less injury prone by switching to barefoot or minimalist running if fully and properly adapted.
  4. Should runners pay attention to their foot strike or should they just let their bodies do what’s comfortable and allow natural biomechanical adjustments to develop without conscious input?
Jan 19, 2016
My guest today is Louise Burke, PhD
Dr. Burke is Head of Discipline in Sports Nutrition for the Australian Institute of Sport. She is also Chair in Sports Nutrition, Mary MacKillop Institute for Health Research, Australian Catholic University. She served as Team dietitian for the Australian Olympic team for the past 5 Olympics ( specifacally in: 1996, 2000, 2004, 2008 and 2012). Her long list of peer-reviewed publications have been cited nearly 4,000 times. She is the author of the books Practical Sports Nutrition and Clinical Sports Nutrition. She is one of the top sports nutrition experts on the planet and she is a world leading expert on today’s topic of fat adaptation in endurance sport training and performance.
How much hype and hyperbole have you heard on the topic of fat adaptation in endurance performance? How often have you wanted the rigorous answers to specific questions on whether the science truly bears out this approach? Within the ultra marathon community, the idea of adapting substrate sources to prefer fat is a very popular topic. The idea is that a higher percentage use of fat will spare glycogen and thereby improve performance in an endurance event. Basically, the intent is to delay running out of internal stores of carbohydrate because it may be challenging to ingest and absorb carbohydrates at a rate that can keep up with use in an ultra marathon.
Today, Dr. Burke helps us understand the history of this topic and cuts straight to the unbiased exploration of the currently available data. Note that this idea has been around for a long time and it’s current popularity is a renaissance of previous waves of enthusiasm. What’s the real skinny on fat adaptation? This episode covers it all, including best practice guidelines for your top performance.
Our wrap-up action items today are the answers to:
  1. What are the most common mistakes Dr. Burke sees ultra endurance athletes making with their overall nutrition? And, what should you be doing?
  2. What would she say to an ultra endurance athlete interested in training and performing at their best today, regarding fat adapting diets?
Jan 5, 2016
My guest today is Michael Joyner, MD. He would need no introduction in the field of exercise physiology. Dr. Joyner is an integrative physiologist, scientist, and evidence-based Anesthesiologist at the Mayo Clinic. His specific areas of expertise include autonomic control of circulation, muscle and skin blood flow, exercise, oxygen transport and metabolic regulation in humans. Additionally, much of his lab’s work in these areas includes the study of aging. This work has been continuously funded by the NIH since the early 1990s. The list of his awards and honors is lengthy; suffice it to say that he has received many of the highest awards in the fields of physiology, medicine, and exercise. Most scientists would feel they had a worthy career with 2 or 3 seminal papers on a subject. My guest today has a list of seminal publications longer than many scientists complete lists. Dr. Joyner published over 350 scientific papers, and many books and book chapters; with many thousands of citations. Simply put, Dr. Joyner is one of the most influential figures in modern exercise science, from molecules & mechanisms to health advocacy. He is also an avid runner.
Later in the interview, you get a glimpse into his knowledge base in the history of running and runners. He rattles off runners and other elite athletes, their ages, and times of performance over many decades. This breadth and depth of knowledge allows him to bring to you amazing insights and many thoughtful ideas….including a haiku!
You can connect with Dr. Joyner at:
His website on Human Limits of Performance
Twitter: @DrMJoyner
His clinical profile at the Mayo Clinic
Dr. Joyner answers many questions, including:
  1. What are the definition(s) of fatigue?
  2. How does ‘fatigue’ differ from ‘tired’ and where do they overlap physiologically.
  3. What are the causes of fatigue in extreme cases or high intensity: occlusion of blood flow, max sprint, constant effort at ~maximal lactate steady state (fatigue in about an hour or two)?
  4. When we talk about VO2max, we generally consider the cardiovascular system - delivery of oxygen-rich blood - as the major limiting factor based on the knowledge that isolated muscle (like in single leg lifts) can consume more oxygen per 100 grams than that same tissue does at whole body VO2max. Is there a role of the cardiovascular system in exhaustion if we maintain fluid and electrolyte homeostasis?
  5. Muscle micro-trauma is likely to be a major cause of fatigue in ultras. First, what exactly is the muscle trauma and damage that is occurring during ultra marathons? Second, is this likely to be a major source of fatigue?
  6. What is the physiological basis of cardiac drift and does it have a role in fatigue or exhaustion?
  7. Fatigue is very complicated when we consider running ultra marathons. What can we say are likely contributors? Are there any factors that might be contributors in higher intensity effort that are not likely to contribute to fatigue in an ultra marathon?
  8. What do we know about aging an endurance performance relevant to fatigue?
  9. In longer events, we are likely to become relatively depleted of stored glycogen before the end of the race. If our event lasts hours…perhaps many hours…longer, and we can consume and absorb 60-90 g of carbohydrates per hour - will substrate availability contribute to fatigue even if we slow down enough to match energy intake with utilization? In other words, is there anything about being in the depleted state for a long period of time (muscle cells contracting with little internal carbohydrate) that shifts efficiency so as to contribute to fatigue?
  10. What do we know about the nature of systemic feedback signals to the brain that may contribute to fatigue/exhaustion in ultras?
  11. What do we know about the brain and motivational fatigue in events that require moderate effort for many hours, over night, and some times even multi-day?
  12. What role does sleep deprivation play in fatigue/exhaustion?
We develop a list of the expected common or primary predicted sources of fatigue/exhaustion in ultra events.
We wrap up with two action questions.
  1. What are the most common misunderstandings for misconceptions about fatigue and exhaustion in ultra endurance performance?
  2. What are the 3-4 most important actions we can take to stave off fatigue or exhaustion in an ultra endurance event (what can we do about the most common causes)?
Dec 29, 2015

My guest today is Jennifer Pharr Davis. She is an author, speaker, and a National Geographic Adventurer of the Year.

Jennifer is among the most well known of American long distance hikers. She holds the record for the women’s FKT for a thru-hike of the Appalachian trail; a record which was the overall outright record for several years and fell by only 3 hrs 12 minutes in the summer of 2015. She has hiked over 12,000 miles on six different continents, including thru-hikes on the Pacific Crest Trail, the Appalachian Trail (three times), the Colorado Trail, the Long Trail in Vermont, the Bibbulmun Track in Australia, and numerous trails in Europe and South America, including the Tour du Mont Blanc, which ultra marathon runners will be familiar with.

Connect with Jennifer:
1) On the trail!
2) Facebook: Jennifer Pharr Davis
3) Twitter and Instagram: JenPharrDavis
4) Her company:
5) Books: Becoming Odyssa and Called Again: A Story of Love and Triumph

She answered many questions on this in depth interview, including:

You hiked that AT in 2005, 2008, and the overall record setting year 2011. Your first women’s record of the trail in 2008 was a bit over 57 days; in 2011 you destroyed that record and did the trail in a bit over 46 days. How did that enormous improvement come about?

Would you describe the demands of a long-distance thru-hike? Granted that weather can have a big impact, what does a ‘typical’ day look like for a long distance thru hiker?

Are you ever running/jogging during a thru-hike or is it all hiking?

Tell us about your training for a thru-hike. In your experience, would a 3-4+ week thru-hike be good training for ultra marathons of 100 miles or longer?

How do you handle sleep deprivation, or functioning on little sleep, for weeks on end? Tell us about your nutrition for a thru-hike.

Tell us about your foot care on a thru-hike.

You wrote an article recently for the New York Times for which you explored the topic of sex differences, or lack thereof, in ultra distance events. Tell us about that.

Tell us about the psychological demands of a major thru-hike.

As an exceptional, experienced, and accomplished ultra-endurance athlete, you have surely had some very dark moments (mentally).
Would you take us to back to your darkest experience, tell us that story and how you handled it?

We wrapped up with some advice for ultra marathon runners interested in tackling a thru-hike.

Dec 22, 2015
My guest today is Patrick Wilson, PhD and RD. He is Assistant Professor of exercise science in the Human Movement Sciences Department at Old Dominion University, in Norfolk, VA, where he also directs the Human Performance Laboratory. He earned a Ph.D. in Kinesiology from the University of Minnesota, where he also received training in the areas of public health and epidemiology. He completed his post-doctoral research training at the Nebraska Athletic Performance Laboratory, specializing in sport nutrition applications for collegiate athletes. And, he is also credentialed as a registered dietitian. 
He has authored numerous peer-reviewed publications covering a wide variety of sport nutrition-related topics. He has conducted both laboratory- and field-based research examining the effects of nutrition on endurance exercise performance, including the effects of carbohydrate composition on gastrointestinal distress and performance during prolonged running. His studies have included marathon runners, ultra-endurance runners, and Ironman competitors.
In this episode, we cover all the angles on gastrointestinal (GI) distress as it applies to ultra runners. You learn the major factors that influence GI distress and how to maximize your chances of keeping your GI tract happy.
In the wrap-up, he answers two key questions.
1. What is the biggest mistake athletes make regarding food/drink intake and GI distress?
2. What take-home recommendation would you give for athletes to reduce their chances of developing GI distress in ultra events?
Dec 15, 2015

William is a 62 year old British and Scottish international athlete and has set 160 ultra distance running records (from 30 miles on the track to 3100 miles/ 5000 kms on the road) at World, British and Scottish level including age-group records.

Connect with William:;  Twitter: @williamsichel;  Facebook:

Since 1994 William has competed in 92 ultra marathons at home and abroad – winning 16 of them. He has also represented Great Britain 11 times and Scotland 7 times.

William has three grandchildren and has been self-employed all his life.

Since 1982 William has lived in the remote Orkney Islands, off the north coast of Scotland, 750 miles north of London.

In this episode we learn all about the training William follows to compete and succeed in extreme ultra endurance events.

Dec 8, 2015
My guest today is…you…and…me.
This episode is all about an amazing new project I’ve created for you. If you don’t want to hear about a new project I have for you, and only what the science on Science Of Ultra - then I’ll be back next week with another amazing Science Of Ultra episode. But, if you want more from me...
Have you ever wondered what it’s really like to have a coach for your ultra training? Is a coach worth the cost? Maybe you have a coach and you wonder how another coach is different. Will a coach really help you to become your best? What are the conversations with a coach like? How exactly does the relationship with a coach work? What sorts of workouts are prescribed? How will I feel following someone else’s prescribed plan every day? How flexible is a coach when life events happen? 
Wouldn’t it be great if you could have the ultimate observer’s experience…to listen to every word between a motivated athlete and a highly qualified coach…to have access to every detail of every workout (even nutrition)…to follow the athletes daily experience…to even be able to ask the athlete questions…the ultimate observer’s experience as if you were there with the athlete for every single step - a completely open book? Wouldn’t that be amazing? Would you like 100% access to follow the journey with an ultra athlete and coach?
That’s exactly what I’m bringing to you now. I’m calling it the Journey to 100. I’ve hired a coach and I’m going to make every aspect of my journey completely open to you, and you can ask me all the questions you like. For the next year, my coach is going to push me towards my first 100 mile race.
This opportunity for you is unprecedented. Never before has there been a completely open, 100% access experience to an ultra athlete’s journey to taking on their first 100 mile race. Nothing like this, with such total access, has ever been done and I’m bringing it to you.
I started Science Of Ultra with a single-minded focus - to connect you with the reliable, valid, and actionable evidence-based knowledge you need to make the most informed choices about your ultra pursuits. I hope that Science Of Ultra is proving to be valuable to you. I absolutely love bringing it to you.
I am now starting a second podcast. The Journey to 100 podcast will be published weekly, just like Science Of Ultra.
However, the Journey to 100 will be focused on giving you what we might call the ‘fly on the wall’ experience. You will be able to listen to my weekly recorded conversations with my coach, you’ll be able to read every workout on the web site, you’ll be able to investigate my nutrition, and you will get my blog posts about my personal experience. In addition, you will be able to ask me questions that I will answer in every podcast episode of Journey to 100. Science Of Ultra will always be exactly what it has been and we have more great science coming in next week’s episode. But, I am using this one episode of Science Of Ultra to let you know about the Journey to 100 because I want you, the loyal Ultra Clan, to be the first to hear about this exciting venture. 
So, how will this work. Well, keep listening to Science Of Ultra episodes every week...
Then join the Journey to 100. While you are on the web site, look at the navigation choices in the top menu. You will find a link to Journey to 100. Click on that menu item link. On the Journey to 100 page, you’ll find all the information you need to join the journey.
Have you ever wondered what the coaching experience is like? Are you interested in what it takes to step up to the 100 mile distance? Maybe you want to become a better 100 mile runner? Maybe you’re just curious. The Journey to 100 is for you! Go to and select Journey to 100 in the menu or go directly to it at
Although Journey to 100 will have it’s own podcast, separate from the Science Of Ultra podcast, I will use the same Twitter, Instagram, and Facebook pages to post for both. So, if you are already following, great! If not, go to and click on the respective follow icons at the top of the page.
When will you ever get to be completely on the inside of a coaching journey focused on a 100 mile ultra race? This is your chance to experience every aspect. Go to (or use the menu link at the top of the main page) to join your Journey to 100.
Dec 1, 2015
Science of Ultra   Episode 13   Carbohydrates for ultra marathon training and racing
My guest today is Asker Jeukendrup, PhD. He is a leading sports nutritionist and exercise physiologist who spent most of his career at the University of Birmingham (UK), where he was a Professor of Exercise Metabolism and Director of Research. He worked the last 4 years for PepsiCo as Global Senior Director of the Gatorade Sports Science Institute Based in Barrington IL (US). He is currently running a consulting business “Mysportscience” and is a visiting professor at Loughborough University. During his career he authored over 200 research papers and book chapters, many of which have helped to change the sports nutrition landscape. He is also the author of 8 books. He is the former editor of the European Journal of Sport Science and Associate editor of the Journal of Sports Sciences. During his career he worked with many elite athletes and teams including several World and Olympic champions. He also practices what he preaches and is competing in Ironman distance triathlons as well as other endurance events. To date he has completed 21 Ironman races including 6 times at the Ironman world Championship in Hawaii. 
You can connect with Dr. Jeukendrup:
Twitter @jeukendrup
Here are some of the questions Dr. Jeukendrup answers:
  1. On a daily basis, what are the carbohydrate needs of an ultra endurance athlete?
  2. How many calories can most people digest and absorb per hour when running?
  3. What is the fate of consumed carbohydrate relative to stores while exercising?
  4. What are the key factors to be considered with respect to the carbohydrates during a long event that may last 24 hrs?
  5. Can we predict when relative glycogen depletion might occur in an ultra marathon?
  6. What should we consider when we are choosing specific high-carbohydrate foods?
  7. What are the key issues to consider relative to the timing of carbohydrate intake prior to, during, and following training workouts?
  8. What about timing of carbohydrate consumption for a race event?
  9. Is glycemic index of a given food different when running vs at rest?
  10. For those who don’t like sweet tastes while exercising or late in races, what are the sources of simple carbs that don’t taste sweet?
  11. Are there data, or any good reason to expect, that any aspect of carbohydrate digestion/optimal sources/etc. will change over the course of an ultra marathon? Does carbohydrate physiology change when we go way beyond the better understood distance of marathon? 
  12. Is consumption of foods that contain protein, fat, or fiber a concern in light of effects on gastric emptying?
  13. When we consume carbohydrate during a run but prior to reaching very low levels of glycogen in muscle and liver, are those calories used more/less/equally to stored muscle glycogen?
  14. Can carbohydrate consumption keep us from reaching a muscle and/or liver glycogen depleted state?
  15. What is the relation between carbohydrates (type, source, complexity?) and likelihood of GI distress?
  16. Tell us about the topic of ‘fat adaptation’ to spare glycogen. From my reading and understanding, there is no good evidence that fat adaptation provides any benefit to endurance performance and it may even impair higher intensity performance (like going uphill) by not ‘sparing’ glycogen but rather by ‘impairing’ glycogen utilization…that apparent sparing may actually be a side effect of impaired utilization.
  17. How does caffeine ingestion interact with endogenous and exogenous substrate utilization?
  18. GI distress late in a race makes it difficult for some people to retain any calories they might swallow. Tell us about this interesting topic of ‘mouth sensing’ and what it might do for us in that situation.
We wrap up with a couple of focused action items:
1) What are the 2-3 biggest mistakes or misconceptions that you see endurance athletes make regarding carbohydrate and fueling for performance? 
2) What advice do you have for runners wanting to dial in their carbohydrate strategies (maximizing calories, best sources for them, etc.) for training and racing? 
Nov 24, 2015

My guest today is Cody Lind. He's sponsored by Scott and, at age 20, is a rising start in the ultra marathon community. He set five course records and placed second in the U.S. Sky Running Series.

We talk about his training, racing, and his perspectives on running. From big weekly mileage to big weekly vertical, Cody trains hard. Learn about his special connection to the Western States 100 mile Endurance Run and what it takes for even a gifted runner to do well in Sky Running in the U.S.

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