Dr. Nick Tiller is an exercise scientist at the Lundquist Institute at Harbor-UCLA, a two-decade ultrarunner, and the author of The Skeptic's Guide to Sports Science and the new The Health and Wellness Lie.

In this conversation: why ultrarunning is, by Nick's cheerful admission, not actually good for you, and why we keep signing up anyway; the red flags that should trip your bullshit detector in 2026; the great protein panic and how a "health halo" turns a Pop-Tart into a recovery food; what the evidence does and very much doesn't say about AG1; KT tape, cupping, and the slippery ethics of selling someone a placebo; and how to stay skeptical without curdling into a cynic whose brain has fallen out.

This episode is brought to you by LMNT, the new Lemonade Iced Tea flavor has been quietly fixing our hydration and our 4pm coffee regrets; grab a free sample pack with any order at drinklmnt.com/UltraSignup.

Featured race: the Ode to Laz Michigan Backyard Ultra, a 4.167-mile loop run every hour on the hour through 8,000 acres of Holly State Recreation Area in Holly, Michigan, on Saturday, July 18. The only way to win is to be the last runner standing, which is why the motto is "finishing last means the most." If you're backyard-curious but not ready to sign over your soul, the Oak Flats 3-hour option lets you dip in for one, two, or three loops. It's a championship-affiliated race, so the winner takes a silver ticket toward the USA national backyard team. Registration closes Thursday, July 16. Sign up at UltraSignup.com.

The Trailhead is part of the UltraSignup Podcast Network.

Ben Ratliff is a former New York Times music critic, a writing professor at NYU, and the author of Run the Song: Writing About Running About Listening, longlisted for the National Book Award and named a finalist for the PEN/Diamonstein-Spielvogel Award for the Art of the Essay, which chronicles what he hears when he brings music into his near-daily runs through the Bronx.

In this conversation, Zoë and Brendan talk with Ratliff about why running made him a better listener, and why the optimal-BPM running playlist is, by his lights, beside the point. He makes the case for listening as active attention rather than ambient wallpaper, explains why some of the slowest and quietest music turns out to be the most enlivening to run to, and pushes back on the idea that "good taste" is something you can buy. Along the way: defamiliarizing a song until it sounds brand new, the strange kinship between a long run and a long DJ set, and how a career critic ends up running to everything from jazz to Ice Spice.

This episode is brought to you by Running Warehouse, where Zoë gets basically all her summer running gear, vests, socks, hats, shirts, and a frankly irresponsible number of gels, with fast shipping and a return policy run by actual humans.

This week's featured race is the FCA Endurance Race in Oakwood, Georgia — a choose-your-own-adventure event on a flat, one-mile paved loop around the University of North Georgia's Oakwood campus. Pick your distance: a 5K, a 10K that detours onto dirt and a stretch of cross-country trail, or a timed race of two, four, six, twelve, or twenty-four hours, with some durations offering a 6 p.m. start so you can run straight into the night. It all happens Saturday, June 6, 2026, and registration stays open right through race day. Sign up at UltraSignup.com.

The Trailhead is part of the UltraSignup Podcast Network.

When you hit the wall at mile 19 of a marathon (or mile 80 of a 100-miler) it feels like your body is the problem. Your legs are concrete, your stomach is in revolt, and the finish line might as well be on the moon. But what if the wall is mostly in your head?

Emily Balcetis is a social psychologist who studies how vision and perception shape motivation: how what people literally see changes what they believe they can do. She runs the SPAM Lab at NYU and is the author of Clearer, Closer, Better: How Successful People See the World. Her TED Talk on why some people find exercise harder than others has been viewed over a million times.

Zoe and Brendan get into why highly motivated runners literally see the finish line as closer than it is, how Joan Benoit Samuelson used a woman in pink shorts to win the first Olympic women's marathon in 1984, and why the wall is a psychological phenomenon rather than a physiological one. Emily explains why willpower isn't a fixed trait you either have or don't, the if-then framework she calls foreshadowing failure, and how negativity bias means our brains lie to us about our own progress, which is why becoming your own accountant might be more useful than another motivational Post-it on the bathroom mirror. Plus: how Emily decided to learn the drums in a one-bedroom Manhattan apartment, and what it taught her about tracking the kind of progress the brain can't see.

This episode is brought to you by LMNT. Try the new 12oz Sparkling at drinkLMNT.com/UltraSignup and grab a free sample pack with any order.

The featured race is the Haul Ass Ultra Running Festival, Saturday, June 6th, in Erie, Colorado. Eight distances on the menu: a 50-miler, 50K, 10K, 5K, and 3, 6, 9, and 12-hour timed events, which means whatever shape you're in and whoever you're bringing along, there's a way to make it work. Sign up at UltraSignup.com.

The Trailhead is part of the UltraSignup Podcast Network.