View all show notes and timestamps on the KoopCast website. Episode overview: Dr. Nicolas Berger is a Senior Lecturer in Sport & Exercise at Teeside University’s Centre for Rehabilitation. In this episode, we discuss the emerging topic of durability in endurance sports and how it applies to ultrarunning. Topics discussed:   1- Why examining physiological variables matter and why determining what variables matter more is important for training design 2- How physiological testing is limiting 3- The concept of durability 4- What affects durability and how to improve it 5- How progression runs useful in some contexts and not in others Episode highlights: (17:26) Muscular fatigue: Gui Millet’s 2011 presentation, ultramarathon runners are more muscular than marathon runners, additional muscle mass may combat fatigue, strength demands of uphill and downhill running, sacrificing running economy for strength and durability (24:00) Strength gains from training: trail runners get strength gains naturally, there is a higher bar for strength training trail runners, strength for running economy in road runners (44:59) DIY-ing your own durability test: consistency of testing, track what you eat and how you feel, measure what you can, keep conditions similar, deciding what training to work on Additional resources: Nic’s profiles- TU Research Profile Google Scholar Profile ResearchGate Twitter Earlier podcast on Durability with Ed Maunder Fatigue and Ultra-Endurance Performance by Guillaume Millet SUBSCRIBE to Research Essentials for Ultrarunning Buy Training Essentials for Ultrarunning on Amazon or Audible Information on coaching- www.trainright.com Koop’s Social Media Twitter/Instagram- @jasonkoop