Rethinking Effort and Intensity for Endurance Athletes with Siren Seiler

“The physiology can be complicated, but the training doesn’t have to be.” In this episode, I am joined by Siren Seiler, a sports physiologist and endurance athlete who brings a unique perspective to the science of performance. Having transitioned from the subjective world of competitive dance to the objective, data-driven realm of endurance running, Siren explores the friction between laboratory theory and real-world application. We discuss the mechanisms of intensity, examining how we move from the three physiological zones defined by lactate thresholds to the more granular five-zone models used by practitioners. We also tackle the practical challenges of monitoring these intensities when moving from the road to the mountains. Siren shares insights into how vertical gain and technical terrain shift the physiological cost of an effort, often rendering traditional pace-based metrics obsolete, and how breathing rate can help fill that gap. We also touch on the apparent conflict between Polarised Training and Double Threshold training and why Norway are so successful in sports. Whether you are interested in the specific mechanics of lactate monitoring or looking for a more robust way to structure your season, this discussion provides the theoretical depth needed to move from simply consuming information to making informed, science-backed training decisions. Looking for coaching or guidance? Read more at https://bornonthetrail.substack.com/p... USEFUL LINKS Contextualizing the Norwegian standardized intensity zone framework in an international sample of endurance practitioners: https://www.researchgate.net/publicat... RELATED BORN ON THE TRAIL CONTENT How To Improve Your Performance by 44% in Just 10 Weeks*: https://bornonthetrail.substack.com/p... Are You a Better Judge of Effort Than Technology?: https://bornonthetrail.substack.com/p... Reviewing Breathing Sensors as a Tool for Workload Monitoring: https://bornonthetrail.substack.com/p... FOLLOW SIREN SEILER LinkedIn:   / siren-amelia-seiler-viken-a07215345   Research Gate: https://www.researchgate.net/profile/... Instagram: https://www.instagram.com/sirenseiler... Personal Website: https://sirenseilercoaching.wordpress... FastTalk Labs: https://www.fasttalklabs.com/byline/s... WATCH THIS SHOW ON OTHER PLATFORMS YouTube:    / @bornonthetrail   Spotify: https://open.spotify.com/show/6o5yHth... Apple Podcasts: https://podcasts.apple.com/us/podcast... Youtube Music:    • Born on the Trail: Going Longer   FOLLOW BORN ON THE TRAIL ON SOCIAL MEDIA Substack: https://bornonthetrail.substack.com/ Instagram:   / bornonthetrail   TikTok:   / bornonthetrail   Facebook:   / bornonthetrail   CHAPTERS ----------------------------- 00:00 Intro 05:49 Why Research Training Intensity? 09:21 Why Does Norway Punch Above its Weight in Sports? 15:58 Standardising Intensity Zones in Norway 21:00 Intensity Zones as a Communication Medium 29:27 How To Set Your Intensity Zones 37:20 Does Injury Change Your Zones? 39:33 Why Do Zones Change Between Sports? 48:52 Confusion Between 5 and 3 Zones 52:30 Intensity for Strength Training 57:28 Prescribing Intensity for Ultra Endurance 1:02:44 Using Breathing Rate as an Intensity Metric 1:11:00 Double Threshold vs Polarised Training 1:21:50 Outro