Forty-Eight Miles, Twelve Thank-Yous: Lex Fridman Takes On the Goggins Challenge

Fridman explains that David Goggins posted a 48-hour challenge: run four miles every four hours, for 12 sessions and 48 miles in total. He took it on to harden his mind in a dimension he does not usually challenge, and admits he is not sure what he is doing and did not think about it much. It was below freezing, icy and windy, so windy that he could not record the intro outdoors.

He adds a twist of his own: a thought experiment in gratitude. He wrote down 12 things he is grateful for, one per session, to think about while running and to discuss afterward. He hopes this strips away the literal and metaphorical fat of the mind, the distractions and busyness, and leaves only what makes life worthwhile.

Fridman says he normally tests himself in intellectual work rather than physical work, so this is a way to see whether he can still be tough. He also mentions he might swap one running session for a training session, and invites viewers to watch to the end to see how long he lasts.

The first thank-you goes to his childhood in Russia and above all his grandmother, whom he credits with love, kindness, toughness and a piercing, minimalist intelligence. He misses her and the wider family deeply. He traces his love of literature, knowledge and curiosity about the human mind back to those early years and to a close childhood friend, Yura, who showed him the value of friendship.

His family had few material possessions, but that did not matter; life centered on relationships, friendships and music. In the second session he thanks his father for a love of physics, science, rigorous math, music and poetry and the ability to find humor in painful things. He thanks his mother for teaching him to express emotion, and his brother, whom he still wants to be like.

On the third run, running in the morning, he reflects on his gratitude to the United States. He jokes about being Russian but says he is a red-blooded American, and praises a country that welcomes immigrants and lets people with a dream compete and cooperate in a diverse pool. In the fourth session he talks about friendship in America, especially his lifelong friend Matt from the Chicago suburbs and others he met in Naperville.

The fifth session is a jiu-jitsu session in place of a run, which he says felt remarkably good and like the calm before the storm. He says the mat is one of the few deeply honest places in the world, because in one-on-one combat sports you cannot hide from the truth and get choked repeatedly by close friends.

For Fridman, the humility this brings is essential for happiness and continuous growth. Being tapped by a 20-year-old blue belt reminds you that you are mortal and not such a big shot, however good you are at programming or science. He ties this to Joe Rogan, whom he looks up to partly because of the humility that accompanies his success.

He thanks the people who taught him, from Philadelphia judo and Balance Studios, where he went from white to black belt, to his current gym in Boston and its trainers. He thinks jiu-jitsu attracts people who enjoy puzzle-solving and curiosity, producing interesting, humbly curious friends. He hopes to keep training for the rest of his life and to stay largely injury-free.

By the sixth session, around 20 miles, he is losing track of the count and focusing on the next step, running about nine-minute miles with some shin splints and ankle pain to avoid aggravating injuries. He says filming is probably the hardest part because it means facing the camera. His gratitude topic is books, especially existential philosophers and writers such as Camus, Nietzsche, Dostoevsky, Kafka and Hesse.

He reads slowly, spending months in a book like a friendship with its author and ideas, and describes transformative moments that made him think about mortality. He mentions Orwell's Animal Farm as a favorite and Ernest Becker's The Denial of Death. His Soviet upbringing meant he never got into science fiction, and he wants to read the Foundation series, Snow Crash and Dune.

By the seventh and eighth sessions the challenge becomes mostly mental. He is grateful for artificial intelligence, the shoulders of giants in computer science, math, neuroscience and psychology, and the feeling of being born at the right time to work on understanding the mind. After a 3 a.m. run he spent an hour at a Dunkin' Donuts with coffee and an audiobook, feeling delirious but happy.

His MIT-era session covers his academic journey, from a PhD in computer science focusing on machine learning to research at Google and the interdisciplinary community at MIT. He says MIT also taught him that academia is not the right place for his dream of large-scale impact through big collaborative moonshot projects.

At 32 miles things are rough and he walks part of the run. He thanks the community of supporters online, including people on Patreon and those who email him. He also thanks the sponsors, explaining that he avoided them at first but at one point genuinely needed money for food and shelter, and he hoped monetization would not get in the way of deep conversations.

He says Cash App took a risk on him, singling out a person named Naveed, and he was surprised that recommending products he already uses felt pleasant. He adds that sponsorship lets him survive while working on his main dream, a startup, and that nothing forces him to accept any particular sponsor. He is candid about the strain: these videos are hard to record and he worries about showing fragility.

At 36 miles he reports a surprisingly energetic stretch after four small cappuccinos, though his pace has slowed from about nine to ten minutes per mile and a headache suggests he needs electrolytes. He discusses eating mostly meat and low-carb, and regrets overeating, including a whole roasted chicken, and says he cares how he feels rather than his weight. His takeaway is that if you take one step at a time, the suffering ends and the good times come.

The tenth session is about his podcast. Fridman is grateful that so many of the busiest engineers and thinkers agreed to talk to him, and says his strategy has been asking "silly profound questions." He cites Elon Musk, who made time twice, and Donald Knuth, who welcomed him into his home and offered hot dogs afterward, along with Eric Schmidt, Eric Weinstein and Sean Carroll.

What moved him most is that these people truly listen, looking him in the eye despite not knowing who he is, which made him happier about the human race. He credits Joe Rogan with showing that there is a hunger for multi-hour conversations, and calls podcasts an exciting medium for long-form discussion.

By 40 miles his muscles are exhausted but there are no injuries, and he says it is just the mind now. He swapped one session for jiu-jitsu but is determined to finish the full 48 miles with an eight-mile run at 7 p.m. He is grateful for the hardship in his life, many recent examples of it self-imposed, and for people who loved him and wanted him comfortable.

He says a fire in him refuses to be mediocre, and he neither does hot baths nor mediocrity. He is endlessly unsatisfied with not realizing his potential and is driving toward a dream, comparing himself to no one, with the metaphor that it is about the dragon, not the princess.

Fridman completes all 48 miles, though he notes he swapped one session for jiu-jitsu and made up the distance in an eight-mile run. Rather than rushing on to the next thing, he savors the moment and walks the last stretch of a 10-mile route. His legs are shot, and he calls it probably the hardest thing he has done physically.

The sessions he found mentally roughest were seven, eight, nine and maybe ten. His main lesson is to take one step at a time, focus on the moment and avoid planning for the future, which got the job done. He closes by thanking Goggins for challenging the world, urging viewers to keep pushing their limits intellectually and physically, and to keep putting love into the world.