Endurance Unlimited

Fueling Insights Explained: Iñigo San-Millán on Optimizing Carbohydrate Intake for Cyclists — Season 7 Ep 9

You're not seeing things. CoachCast has been renamed Endurance Unlimited. Stay tuned for more great episodes and more. Now, on to this episode... Dr. Iñigo San-Millán explains the science and strategy behind optimal cycling nutrition. Learn how TrainingPeaks' new Fueling Insights feature leverages decades of his metabolic research data to help athletes and coaches evaluate and individualize fueling plans based on athlete metrics, not guesswork. From breaking through the outdated 40-gram carb ceiling to personalizing race-day nutrition for every level of today's cyclist, learn how this tool is changing how we plan, perform and recover. 03:34 Iñigo Intro and Current Roles 07:50 Revamping Carbohydrate Intake for Athletes 12:41 Metabolic Flexibility 14:28 Pioneering Carbohydrate Oxidation Research 19:08 Fat Oxidation Misconceptions in Athletes 21:07 FATMAX: Peak Fat Oxidation Point 26:30 Race Performance and Energy Expenditure 27:48 Balancing Glycogen for Athletes 31:05 Cyclists' Nutrition & Intensity 38:31 Fueling Insights Workout Calculation Steps 39:48 Metabolism Variability Among Individuals 44:32 Risks of Fasted Workouts 47:16 Understanding Gross Efficiency Limitations 56:54 The Nutrition Evolution Learn more about Fueling Insights Learn more about TrainingPeaks Episode 1, Season 5: The Biochemistry of Zone 2

From Couch Potato to World Champion: April Zilg on Coaching and What Makes a Great Paddle Athlete — Season 7 Ep 8

The evolution of paddle sport racing is pushing the limits of endurance competition, where training technology and data-driven coaching play a significant role. April Zilg, world champion paddle athlete, joins the show to share her journey from "couch potato" to the top of the stand up paddle board (SUP) world—all powered by smart training, dedication and data. In this episode, April reveals how technique-focused coaching, a science-based approach to training and leveraging TrainingPeaks shapes her work with athletes of all levels. Get a crash course in the many flavors of paddle sports—from lightning-fast sprints to epic 1,000-mile adventures—and how race type, equipment and environment shape effective training strategies. April stresses the importance of tracking progress, balancing intensity and recovery, and being open to new technology, including heart rate and (soon) power meters on the water. Whether you're curious about SUP racing, endurance coaching, or just want a peek behind the paddle, this episode is full of valuable coaching and training tips.

Gravel's Evolution: Dylan Johnson Talks Unbound, Training, Gear Choices & Strategy — Season 7 Ep 7

In this episode, host Dirk Friel sits down with professional gravel racer and Ignition Coaching coach Dylan Johnson to dig into all things gravel. They break down the cutting-edge equipment trends seen at the 2025 edition of Unbound Gravel, as well as training trends, nutrition and training tips for both amateurs and pros. Hear why mountain bike tires are dominating the scene, the evolving role of aerodynamics in the sport, and the reasons behind faster race times over the last few years. Whether you're a seasoned cyclist or a gravel-curious newcomer, you'll hear expert advice on your next gravel race and the new "Unbound Block" approach to training. Dylan also offers a glimpse into the future of even faster gravel racing. To learn more about Dylan Johnson, check out his training plans or follow him on YouTube and Instagram.

Fixing Food Culture in Endurance Sports Beyond Carbs and Calories — Season 7 Ep 6

In this episode of the CoachCast, host Dirk Friel sits down with Kristen Arnold, a registered dietitian, elite cycling coach, and former pro racer, to unpack the complex relationship endurance athletes often have with food and body image. Drawing from her coaching and clinical experience, Kristen explores how disordered eating patterns can quietly surface in training environments that overemphasize being lean, disciplined, or performing at any cost. Kristen offers practical strategies for coaches and athletes to identify red flags, reframe food as fuel (not a reward or punishment), and prioritize long-term health alongside results. From race-day fueling to an off-season mindset, this conversation challenges outdated norms and empowers listeners to pursue performance with compassion, curiosity, and balance. Resources discussed in this episode: Environment and Language Guide for Discussing and Managing Physique USOPC Sports Nutrition Resources for Young Athletes Directory of Registered Dietitians Sports Nutrition for Women E-Course HEXIS App Fulein App

From Racing Pro Motocross to Running the Boston Marathon with Coach Alex Martin — Season 7 Ep 5

In this episode, Dirk Friel talks with Alex Martin, a former professional motocross and supercross racer who spent over 15 years competing at the highest level, earning podiums and top-five finishes. After retiring from racing as a pro, Alex leaned into his passion for training and performance, co-founding Troll Training. His coaching company blends motocross performance with endurance sports methodologies. Alex shares his journey from motocross to recently catching the “running bug” and how structured training, especially via TrainingPeaks, helped him transform his racing career and life after retirement. He just raced the 2025 Boston Marathon, finishing at 2:48:35, just shy of a PR, with plans to run several other big races in the coming months. From building marathon fitness as a busy dad and coach to balancing strength, endurance, and recovery in high-risk motorsports, Alex shares an insider’s look at taking advantage of experience and science to advance the art of coaching unique athletes.