
Human Performance Outliers Podcast with Zach Bitter
Welcome to the Human Performance Outliers Podcast. Your host Zach Bitter, will take you through a series of interesting topics around health, fitness, endurance, running, hybrid athlete training, ultramarathon, and nutrition. Join in for interviews with folks exploring their outer limits and research in a wide variety of sports, fitness, and nutrition.
Latest episodes

Jul 3, 2025 • 37min
Episode 446: WSER 100 - What We Learned
WSER 100 is becoming one of the most recognized and high stakes 100 mile ultramarathons for both professionals and ultramarathon participants. we can learn a lot about how participants are preparing and completing this event. Here are some things to consider from what we learned at the 2025 WSER 100. Heat adaptation and in race management The power of race day expectations The psychology around group and competitive pressure Considerations around varied weather events The role of super shoes on the trails Endurance Training Simplified Series LMNT: drinkLMNT.com/HPO (free sample pack with purchase) deltaG: deltagketones.com Code: BITTER20 (20% Off) Maui Nui Venison: mauinuivenison.com/bitter CurraNZ: curranzusa.com Code: Bitter20deal (20% Off) Support HPO: zachbitter.com/hposponsors HPO Website: zachbitter.com/hpo Zach’s Coaching: zachbitter.com/coaching Zach’s Newsletter: substack.com/@zachbitter Find Zach: zachbitter.com - IG: @zachbitter - X/Tw: @zbitter - FB: @zbitterendurance - Strava: Zach Bitter

Jun 30, 2025 • 1h 34min
Episode 445: Jeff Garmire | Cocodona, Media, & Doping Control in Ultra
Jeff Garmire is a professional ultramarathon athlete, coach, author, podcast host, and one of a very few to have participated in all Cocodona 250 events. Long ultras are not even long for Jeff, as he has also completed some monster through hikes like John Muir Trail, Arizona Trail, Continental Divide and more. He is currently gearing up for an unsupported attempt on the Appalachian Trail in August. Endurance Training Simplified Series Zach’s Low Carb Endurance Approach Series LMNT: drinkLMNT.com/HPO (free sample pack with purchase) deltaG: deltagketones.com Code: BITTER20 (20% Off) Maui Nui Venison: mauinuivenison.com/bitter CurraNZ: curranzusa.com Code: Bitter20deal (20% Off) Support HPO: zachbitter.com/hposponsors HPO Website: zachbitter.com/hpo Zach’s Coaching: zachbitter.com/coaching Zach’s Newsletter: substack.com/@zachbitter Find Zach: zachbitter.com - IG: @zachbitter - X/Tw: @zbitter - FB: @zbitterendurance - Strava: Zach Bitter Jeff: freeoutside.com | IG: @thefreeoutside | YouTube: @JeffGarmire | Podcast: Free Outside Podcast

Jun 24, 2025 • 1h 34min
Episode 444: WSER 100 | Meghan Canfield: 13 Finishes, 10 top 10
Meghan Canfield has a deep history and love for the WSER 100 Endurance Run, completing it 13 times and finishing in the top 10 on 10 occasions. She has been a long time friend, and big influence on the ultramarathon community. She joined me to discuss why the WSER 100 is unique, her many experiences with this event, as well as growing with the sport. Meghan: zenithcoaches.com/about-us/meghan-canfield - IG: @runningmegleg Endurance Training Simplified Series LMNT: drinkLMNT.com/HPO (free sample pack with purchase) deltaG: deltagketones.com Code: BITTER20 (20% Off) Maui Nui Venison: mauinuivenison.com/bitter CurraNZ: curranzusa.com Code: Bitter20deal (20% Off) Support HPO: zachbitter.com/hposponsors HPO Website: zachbitter.com/hpo Zach’s Coaching: zachbitter.com/coaching Zach’s Newsletter: substack.com/@zachbitter Find Zach: zachbitter.com - IG: @zachbitter - X/Tw: @zbitter - FB: @zbitterendurance - Strava: Zach Bitter

Jun 11, 2025 • 24min
Episode 443: Ultra Updates - Cheating in Ultra?
This episode covers some current topics in the ultramarathon world. Topics covered include; big name injuries a result of high volume training and shoes, has ultramarathon growth and access resulted in cheating, Gerda Steyn the Queen of Comrades. Edit: Gerda Steyn has won Comrades 4x: '19, '23, '24, '25 Endurance Training Simplified Series Zach’s Low Carb Endurance Approach Series LMNT: drinkLMNT.com/HPO (free sample pack with purchase) deltaG: deltagketones.com Code: BITTER20 (20% Off) Maui Nui Venison: mauinuivenison.com/bitter CurraNZ: curranzusa.com Code: Bitter20deal (20% Off) Support HPO: zachbitter.com/hposponsors HPO Website: zachbitter.com/hpo Zach’s Coaching: zachbitter.com/coaching Zach’s Newsletter: substack.com/@zachbitter Find Zach: zachbitter.com - IG: @zachbitter - X/Tw: @zbitter - FB: @zbitterendurance - Strava: Zach Bitter

May 29, 2025 • 1h 35min
Episode 442: Wild Hunt Conditioning 1100 Mile Project & Rarámuri Tribe
James Pieratt of Wild Hunt Conditioning joined me to catch up before he kicks off his 1,100 mile journey along the West Coast and discuss the famous Rarámuri Tribe's endurance practices and lifestyle. Audio Endurance Training Simplified Series Zach’s Low Carb Endurance Approach Series LMNT: drinkLMNT.com/HPO (free sample pack with purchase) deltaG: deltagketones.com Code: BITTER20 (20% Off) Maui Nui Venison: mauinuivenison.com/bitter CurraNZ: curranzusa.com Code: Bitter20deal (20% Off) Support HPO: zachbitter.com/hposponsors HPO Website: zachbitter.com/hpo Amazon Store: amazon.com/shop/zachbitter Zach’s Coaching: zachbitter.com/coaching Zach’s Newsletter: substack.com/@zachbitter Find Zach: zachbitter.com - IG: @zachbitter - X/Tw: @zbitter - FB: @zbitterendurance - Strava: Zach Bitter James: wildhuntconditioning.com - IG: @wildhuntconditioning

May 23, 2025 • 1h 16min
Episode 441: Cocodona 250 Record Breaking Performance - Dan Green
Dan Green recently won the Cocodona 250 and broke the course record along the way with a time of 58:47:18. Prior, Dan has found success running fast times at the Javelina 100, including breaking 13 hours last year and landing on the podium. Dan Green: IG @danisgreen - YouTube: @BargainBoysMedia Endurance Training Simplified Series Zach’s Low Carb Endurance Approach Series LMNT: drinkLMNT.com/HPO (free sample pack with purchase) deltaG: deltagketones.com Code: BITTER20 (20% Off) Maui Nui Venison: mauinuivenison.com/bitter CurraNZ: curranzusa.com Code: Bitter20deal (20% Off) Support HPO: zachbitter.com/hposponsors HPO Website: zachbitter.com/hpo Amazon Store: amazon.com/shop/zachbitter Zach’s Coaching: zachbitter.com/coaching Zach’s Newsletter: substack.com/@zachbitter Find Zach: zachbitter.com - IG: @zachbitter - X/Tw: @zbitter - FB: @zbitterendurance - Strava: Zach Bitter

May 19, 2025 • 1h 28min
Episode 440: 603 Miles in 6-Days | Megan Eckert
Megan Eckert is a World Record holding ultramarathon athlete for Mount to Coast, teacher, and coach. She recently broke the women's 6-Day World Record, by completing 603 miles. She holds the women's Backyard Ultra record with 87 laps for 362 miles, qualified for Team USA's 24-Hour World Championship Team, and much more. Endurance Training Simplified Series Zach’s Low Carb Endurance Approach Series LMNT: drinkLMNT.com/HPO (free sample pack with purchase) deltaG: deltagketones.com Code: BITTER20 (20% Off) Maui Nui Venison: mauinuivenison.com/bitter CurraNZ: curranzusa.com Code: Bitter20deal (20% Off) Support HPO: zachbitter.com/hposponsors HPO Website: zachbitter.com/hpo Zach’s Coaching: zachbitter.com/coaching Zach’s Newsletter: substack.com/@zachbitter Find Zach: zachbitter.com - IG: @zachbitter - X/Tw: @zbitter - FB: @zbitterendurance - Strava: Zach Bitter Megan: @_megeckert irunfar article: https://www.irunfar.com/megan-eckert-womens-six-day-world-record-2025-interview

May 13, 2025 • 1h 46min
Episode 439: Ultra Running Success - Alyssa Clark
Alyssa Clark, a professional ultramarathon runner with impressive wins at events like Moab 240, shares her journey from athlete to coach. She opens up about managing ulcerative colitis while fueling for endurance runs, highlighting the importance of personalized nutrition strategies. Their conversation dives into the latest trends in ultraracing, the evolution of race formats, and the significance of balance in off-season training. Alyssa's insights on adapting fueling methods and embracing diverse race experiences offer a fresh perspective on ultra running challenges.

May 1, 2025 • 1h 39min
Episode 438: Ultra World Records & National Championships - Charlie Lawrence
Charlie competed in D1 Cross Country and Track & Field for the University of Minnesota. He currently holds the World Record for the 50 Mile, 4:48:21 (5:46/mi). He recently won the USATF 50 KM Road Championships in a time of 2:49:01. Endurance Training Simplified Series Zach’s Low Carb Endurance Approach Series LMNT: drinkLMNT.com/HPO (free sample pack with purchase) deltaG: deltagketones.com Code: BITTER20 (20% Off) Maui Nui Venison: mauinuivenison.com/bitter CurraNZ: curranzusa.com Code: Bitter20deal (20% Off) Support HPO: zachbitter.com/hposponsors HPO Website: zachbitter.com/hpo Amazon Store: amazon.com/shop/zachbitter Zach’s Coaching: zachbitter.com/coaching Zach’s Newsletter: substack.com/@zachbitter Find Zach: zachbitter.com - IG: @zachbitter - X/Tw: @zbitter - FB: @zbitterendurance - Strava: Zach Bitter Charlie: IG: @lawrence_char - YouTube: youtube.com/@lawrence_char

Apr 18, 2025 • 1h 14min
Episode 437: Backyard Ultras with Sam Harvey
Sam Harvey is one of the best Backyard Ultra runners in the World. He was part of the legendary push that resulted in three men breaking the World Record at the Big’s Backyard Ultra Championships in 2023. He has a wide range, which he recently showcased by winning the Tarawera 100 mile this year. Endurance Training Simplified Series Zach’s Low Carb Endurance Approach Series LMNT: drinkLMNT.com/HPO (free sample pack with purchase) deltaG: deltagketones.com Code: BITTER20 (20% Off) Maui Nui Venison: mauinuivenison.com/bitter CurraNZ: curranzusa.com Code: Bitter20deal (20% Off) Support HPO: zachbitter.com/hposponsors HPO Website: zachbitter.com/hpo Amazon Store: amazon.com/shop/zachbitter Zach’s Coaching: zachbitter.com/coaching Zach’s Newsletter: substack.com/@zachbitter Find Zach: zachbitter.com - IG: @zachbitter - X/Tw: @zbitter - FB: @zbitterendurance - Strava: Zach Bitter Sam: samharveyultra.com - IG: @samharvey_cloudlander