Endurance Unlimited

Host Dirk Friel is joined by sleep researcher and sleep coach Charlotte Edelsten, whose expertise is backed by over two decades of research on sleep and performance. Together, they dive deep into the science behind sleep for endurance athletes—addressing why sleep is a true foundation for training adaptations, injury prevention, and race-day performance.

Charlotte Edelsten shares insights from her years conducting research at high-profile endurance events like UTMB Mont Blanc, unpacks why many athletes struggle with sleep quality (even Olympians!), and dispels myths about supplements and wearables. She discusses practical strategies for managing sleep during training and competition, including napping protocols, sleep banking, and how to optimize rest at altitude or before an ultra-endurance race.

00:00 "Endurance Training & Sleep Insights"

03:37 Sleep Disturbances in Athletes

09:10 Caffeine: Adenosine Blocker Explained

11:10 Limitations of Sleep-Tracking Devices

13:21 "Sleep's Impact on Athletic Performance"

18:46 "Understanding Sleep Through Sleep Diaries"

20:54 "Supplements Won't Cure Sleep Issues"

26:07 "Pre-Race Sleep and Mindset"

29:18 "Sleep Strategies and Performance"

31:01 "Gradual Sleep Extension for Athletes"

33:39 "Strategic Napping in Sports"

37:39 "Optimizing Sleep for Best Rest"

42:09 Sleep's Role in UTMB Success

43:49 "Fatigue Management for Runners"

47:42 "Caffeine Strategies in Training"

50:51 "Hallucinations From Extreme Sleep Deprivation"

55:12 "Endurance Unlimited: Follow & Train"

On this episode of Endurance Unlimited, host Dirk Friel sits down with rising star Cam Smith, professional trail runner and ski mountaineering athlete who's just qualified for the 2026 Winter Games in Milan Cortina. Together, they dig into the strategy and preparation behind Team USA’s dramatic World Cup victory in Solitude, Utah—which not only put the U.S. a ticket to the Games for Skimo, but also set the stage for what’s next in this fast-evolving sport.

Cam Smith shares his journey from ultra-endurance races to the high-intensity, quick-transition world of ski mountaineering, offering a behind-the-scenes look at the training philosophies, mistakes to avoid, and the unique demands of mixed relay competition. You’ll hear how he leverages both running and skiing to fuel his performance, and get an inside look at how emerging talent like Anna Gibson is shaking up the U.S. team.

00:00 "Mixed Relay Racing Strategies"

03:32 "Qualifying on Home Soil"

07:50 "Trail Running Meets Skiing"

12:44 "Balancing Racing Seasons and Goals"

15:41 "Short Turnaround: Leveraging Speed"

17:45 Training for Steep Mountain Racing

22:48 "Injuries, Adaptation, and Focus"

24:39 Future Trail Racing Plans

29:30 "Building a Strong Skimo Team"

31:26 "Join Our Thriving Federation"

36:50 "Pacing Strategies in Racing"

38:38 Downhill Training for Racing Success

43:02 "Post-Season Training Reset"

45:19 "Skimo's Impact and Future"

48:40 "Inspiring the Next Generation"

In this episode, Host Allison Bettin is joined by Matt Dixon, an elite triathlon coach and cofounder of Purple Patch Fitness, for an athlete-focused episode on the off-season, including practical strategies to help athletes integrate their training with work, family, and life, as well as building systems that drive long-term success.

Instead of chasing peak fitness or pushing for higher power numbers, Matt urges athletes to focus on rejuvenation, consistency, and building foundational habits that set the stage for breakthroughs later in the season. He makes it clear: the off-season is not about piling on more work, but fine-tuning the invisible groundwork, like sleep, nutrition, strength training, and skill development.

Whether you’re a dedicated competitor or just striving to be your best, tune in for expert tips and actionable advice that will help you come back stronger, faster, and ready to tackle your goals head-on. If you’re wondering how to structure your downtime for maximum gain, this episode is packed with real-world wisdom on building consistency, adopting a “challenge mindset,” and making off-season training not just effective, but fun and fulfilling.

In this episode, Host Allison Bettin is joined by Matt Dixon, an elite triathlon coach and cofounder of Purple Patch Fitness, for a masterclass on the offseason—the time of year Matt Dixon boldly claims is the single biggest predictor of athlete breakthroughs.

Together, they unpack Matt Dixon’s four-phase coaching model and explore why offseason isn’t just a break, but a critical opportunity for reflection, realignment, and revolutionizing athletic potential. You’ll hear actionable insights on athlete retention, the art of the season review, what mistakes coaches often make, and how to turn downtime into your most powerful training advantage.

Plus, discover the holistic habits and “offseason toolkit” that make the difference between a good athlete and a great one—along with practical ways TrainingPeaks brings it all together.

Host Dirk Friel sits down with Dr. Scott Frey, author, neuroscientist, and psychologist, for a deep dive into the critical role that the brain plays in endurance sports performance.

Scott Frey explains how the brain is the "central command and control center" for both physical and cognitive performance, and how neuroplasticity—our brain's ability to change—offers untapped potential for athletes. Scott breaks down how mental fatigue impacts physical output and why neglecting “brain tapering” could be holding you back on race day.

Discover the science behind neuroplasticity, actionable strategies to regulate stress and arousal, and why even top performers may be leaving “low-hanging fruit” on the table by not deloading cognitive stress before big events. Whether you’re coaching, competing, or striving for your personal best, this episode is packed with insights and practical tips to harness the power of your brain for peak performance.

00:00 From Running to Brain Research

06:11 "From Science to Sport Mastery"

13:48 "Optimizing Performance Through Neuroplasticity"

20:44 "Brain's Role in Workout Performance"

23:13 "Tapering Cognitive Load for Athletes"

27:17 "Training Decision-Making Under Fatigue"

36:13 "Rethinking Brain Training Methods"

38:15 "Training for Resilience and Balance"

44:08 "Brain Signals and Survival"

48:53 Measuring Cognitive Fatigue in Training

56:37 "Concussion Effects and Recovery"

01:00:18 "How Brains Heal Differently"