Why Trail Running Breaks the Rules of Exercise Science with Dr. Simon de Waal

In road running, VO2max, lactate threshold, and running economy can explain up to 95% of the variation in performance between athletes. In trail running, that same model barely holds together, with running economy being the worst predictor of the three.In this episode, Dr. Simon de Waal walks through his research journey trying to work out why. From his systematic review of the existing evidence, to a full pacing analysis of Ultra Trail Cape Town using Strava data and treadmill testing at steep gradients. Along the way we cover velocity at VO2 max as a hidden composite metric, why uphill-specific testing changes the picture, why downhill collapse is the clearest sign of mechanical fatigue late in a race, and why prior race results still beat most lab tests.It's a comprehensive look at just how multifactorial trail performance really is, and why researchers are still working out how to measure it properly.Dr Simon de Waal grew up running trails around Cape Town before turning it into a research career. He completed his PhD at Stellenbosch University under cycling physiologist Robert Lambert, and now researches trail running performance at the University of Gloucestershire while coaching through Rooted in Dirt.Looking for coaching or guidance? Read more at https://bornonthetrail.substack.com/p/coachingRELATED BORN ON THE TRAIL CONTENTYour Watch Doesn't Understand Trail Running Performance: https://bornonthetrail.substack.com/p/your-watch-doesnt-understand-trail?r=39kjk2Analysing the Limiters of Ultra Marathon Performance: https://bornonthetrail.substack.com/p/analysing-the-limiters-of-ultra-marathon-performance?r=39kjk2How To Improve Your Performance by 44% in Just 10 Weeks*: https://bornonthetrail.substack.com/p/how-to-improve-your-performance-by?r=39kjk2Why Do Ultra Endurance Athletes Get Better With Age?: https://bornonthetrail.substack.com/p/why-do-ultra-endurance-athletes-get-better-with-age?r=39kjk2The Overlooked Aspects of Ultramarathon Training: https://bornonthetrail.substack.com/p/overlooked-aspects-of-ultramarathon-training?r=39kjk2FOLLOW DR. SIMON DE WAALWork with Dr. de Waal at https://www.glos.ac.uk/staff/profile/simon-de-waal/ or by contacting him at [email protected] to get coached by Dr. de Waal? Find him at https://rootedindirt.com/ and https://www.instagram.com/rootedindirt/WATCH THIS SHOW ON OTHER PLATFORMSSubstack: https://bornonthetrail.substack.com/podcastYouTube: https://www.youtube.com/@bornonthetrailSpotify: https://open.spotify.com/show/6o5yHthUidO0No4VA3xdVbApple Podcasts: https://podcasts.apple.com/us/podcast/born-on-the-trail-going-longer/id1857231629YouTube Music: https://music.youtube.com/playlist?list=PLvFOih1rUBA2F_3Bi7Ii-cAqieAQSumU_FOLLOW BORN ON THE TRAIL ON SOCIAL MEDIASubstack: https://bornonthetrail.substack.com/Instagram: https://www.instagram.com/bornonthetrail/TikTok: https://www.tiktok.com/@bornonthetrailFacebook: https://www.facebook.com/bornonthetrail/ Get full access to Born on the Trail at bornonthetrail.substack.com/subscribe