How to Run 100 Miles: The Art and Science of Endurance-Week 8

Physiology First
7 min readDec 19, 2021


I’m starting week 8 off with this quote by Robert Sapolsky for a reason…

Whenever we dive into the dopamine pathways which fuel goal-directed, reward seeking behavior we want to preface that the scientific lens for motivation and drive only furthers the mystery and awe that we have for human accomplishment and will in our eyes.

We have evolved to pursue actions that further our chance of survival. This process is beyond fascinating-and truly beautiful. The fact that we can now pursue something as “not conducive” to baseline survival as running for 24+ hours for recreation is a testament to how far we’ve come on this evolutionary ride know as being a human being.

It’s also a really important subject to us. We’ve seen far too many athletes-in endurance sports in particular-suffer from depression and addiction related issues that either precipitate, derail, or dead end their passion for long distance pursuits. The ties between athleticism and addiction are deep, and they are neurophysiological in nature. The same chemical that compels us to lace up our trail running shoes on a frigid winter morning is the chemical responsible for our most addictive drives.

In the book Dopamine Nation author Anna Lembke breaks down the role of dopamine in addiction. It is a fascinating glimpse into the power of a single molecule working in conjunction with a complex system to mark behaviors as worthy of returning to-at first-and ultimately, irresistible.

This interview between Anna Lembke and Dr. Andrew Huberman who Lex and I have had the immense pleasure of meeting years ago through his pioneering virtual reality studies on the physiology of stress and anxiety at Stanford University is a great place to start when learning about dopamine pathways. I believe that it touches on the athletic implications-but if I’m wrong the book does, a little.

I say “a little” because endurance running and ultramarathon training is a different beast altogether. From the way that Anna talk about ice baths in her book it is clear that her exposure to peak performance training is limited-I can’t imagine what she would think of the fact that many of us routinely run from sunset to sundown and through the next sunset….with that said, the book and this podcast are phenomenal resources for better understanding how our brain drive our bodies to do the things that we do.

(David in a V.R simulation involving great white sharks, attack dogs, and other “stressors” engineered to better understand the science of stress and anxiety.)

(Distance Project coach and Physiology First board member Lex Clark and Dr. Andrew Huberman at Stanford University.)

Although the conversation with Anna is interesting on many levels, the deep dive into dopamine below on this solo show with Dr. Huberman may be a more “to the point” resource from an athletic and personal application perspective.

(If some of the elements around “eliminating dopamine” sound a bit extreme consider the context of running and ask yourself whether you still feel the same level of excitement and motivation as you did when you first started…and what small tweaks, like varying your running route, running with or without music, or simply forgetting to add a healthy amount of variance to your training so that it does not become a monotonous habit as opposed to a practice that you look forward to and love!)

When we think about the drive for dopamine in relation to running we end up with an informed lens into one of the most interesting and brilliant mechanisms that nature could have designed….

Running produces a rush of endocannabinoids, the same chemicals mimicked by cannabis. This makes exercise initially pleasurable while raising baseline levels of serotonin and dopamine to elevate mood and ingrain the behavior into a desirable one to pursue again. This keeps us motivated to pursue an active lifestyle and seems like a “win/win” from an evolution standpoint.

The challenge begins when the neurochemical cascade is increasingly out of alignment with the rest of our days i.e-sitting in an office for 8–9 hours and dying to get outside to run as opposed to spending the day gently covering 12–13 miles as we have throughout our history. Another challenge presents itself when maintaining increases serotonin and dopamine levels requires a new baseline level of physical activity that we have linked to one modality-running. Often runners struggle to find the same “feeling” in other training methods such as strength training which makes dedicating the time allocated to physical activity each day to the thing that makes us feel our best and seems most directly related to our goals a “no brainer.”

From years of coaching endurance athletes we’ve seen the same trajectory repeat itself in both the favorable outcomes (athletes with few to no injuries doing what they love year after year) as well as the less favorable (athletes ditching the strength training program for the same high mileage programs that left them injured last time and drove them to strength training until they suffer the injury that takes them out of both domains at which time their mental health suffers as physical activity goes from a near constant to something they can not do without pain.)

Often this is due to a lag in what the strength training offers the athlete from a neurochemical perspective. Those new to strength training often lack the strength to get a huge hormonal and chemical dose of satisfaction from a squat or deadlift workout. It feels like work, like maintenance, and like something that they “have” to do in order to continue doing the stuff that’s really fun. However, when you can add a timer and an element of intrigue (can I get all of these reps accomplished in this timeframe? Can I perform this 70 rep dumbbell cycle without putting the weights down?) the excitement, fun, and reward are all ratcheted up. Notice how the 30/30 training cycle that we started last week feels compared to traditional strength training. See if it makes you more excited to lift and leaves you feeling less like you “need a run” afterwards.

If so, incorporate these training methods into your health and fitness repertoire more often throughout the course of your lifespan. Another trend that we see often is endurance athletes getting extremely consistent with a strength training program that they love….and then not knowing what to “do” when it’s done.

Hopefully this model increases the drive to lift while building some serious strength over the next several weeks! You will definitely feel the impact and the benefit on the trails this summer.

For this week’s training we are using the exact same formula as last week. The only difference is to add the smallest amount of weight possible to each lift on the 30/30 cycle.

We are adding in the addition of a short sprint cycle before the strength training sessions consisting of 8 rounds of 15 second hard/ 45 seconds easy sprinting. The goal is to keep our bodies in “sprint ready condition” while still adapting to the workload of this 30/30 training cycle. Use the sprint warm-up matrix beforehand and approach the sprints at a roughly 70% effort. You should be able to maintain nasal breathing throughout the entire cycle.

Another addition is adding one mile to the first aerobic base day (so a 9 mile run) and 2 miles to the second day (so a 12 mile run.)

The final addition is to incorporate 2 sets of 8 single leg glute bridges after day two of the strength cycle. Lex demonstrates them at minute 35:31 of this week’s Physiology First in Action Live Workout:

We have a live discussion on dopamine and endurance sports on the PFU platform tonight at 7pm EST if you’re reading this program in “real time!” Show up to ask questions and hear some of our personal experiences as athletes and coaches!

Wishing everyone an absolutely awesome holiday week if you’re celebrating and hope that you enjoy the second exposure to the 30/30-we’re on week 3 ourselves at the training center and we have roughly 25 athletes who are sweating, smiling, and toughing their way through this difficult workout-while meeting all of their daily dopamine requirements ;)

BTW: Another way to increase dopamine levels is to take a cold plunge. The students below (including PF Board Member Ethan Smith, 15) visited the Physiology First University campus as well as The Distance Project last week to hear a talk by Lex on how to thrive as a student in an age of disruption. They jumped into the lobster tank full of very icy water afterwards….at least 3 of then did ;) Your support of the platform makes this work with students possible-so thank you for helping us share science based tools for improving mental health and mental fitness with the next generation!




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