Harvard evolutionary biologist Dan Lieberman is the scientist whose work reshaped how we understand running. His research on human evolution helped popularize the idea that we’re born to run, that our bodies, from our toes and tendons to our oversized glutes, are uniquely adapted for endurance. In this conversation, he joins Zoë and Brendan to explore what running reveals about being human.

We dig into why ultrarunning is evolutionarily bizarre but still deeply natural, what persistence hunting really looked like, and how belly fat, treadmills-as-torture-devices, and even the barefoot craze all tie into our running story. It’s part science lesson, part reminder that while we didn’t evolve for nipple tape, running is still one of the most human things we do.

Thanks to LMNT for supporting The Trailhead!

Joe Grant has always blurred the lines between athlete and artist. From racing UTMB and Hardrock to biking between Colorado 14ers, Joe’s career has evolved into something bigger than competition—projects that fuse endurance, place, and creativity. In this conversation, Joe joins hosts Zoë Rom and Brendan Leonard to talk about his journey from racing to FKTs to local San Juan projects, why he ditched the watch, and how he balances gear geekery with poetry and film photography.

If you’ve ever wondered how running can fuel creative work—or vice versa—this episode goes deep into what it means to truly be present on the trail.

Thanks to Running Warehouse for sponsoring The Trailhead!

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🎧 Check out other shows on the UltraSignup Podcast Network:

• The Buzz with Buzz Burrell — grounded takes on the big ideas shaping trail and ultrarunning.

• Between Two Pines — conversations that connect trail running with culture, community, and the outdoors.

This week on The Trailhead, Zoë Rom and Brendan Leonard sit down with one of ultrarunning’s most quietly legendary figures: Junko Kazukawa. A two-time Leadwoman, breast cancer survivor, and one of the few athletes to complete both the Grand Slam of Ultrarunning and the Leadwoman series in a single year, Junko’s story is a masterclass in resilience and joy.

Born in Sapporo, Japan, and now based in Denver, Junko shares how she started running in the U.S. after coming over as a student, how she trained through cancer treatments, and why she still lines up for 100- and 200-mile races at age 62. She talks about the identity and community she’s built through the sport, how her view of fitness has evolved over decades, and why she believes “glutes are everything.”

We also hear about her favorite races around the world, from the Tour de Géants to Mount Fuji, and what keeps her motivated to take on new challenges even as recovery gets harder with age. Whether you’re chasing your first ultra or your 26th, Junko’s joy and perspective will make you want to lace up and keep going.

Thanks to Running Warehouse for supporting The Trailhead. Check out their great selection of everything from shoes to nutrition, packs and socks, with free two-day shipping.

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