View all show notes and timestamps on the KoopCast website. Episode overview: Jeff Rothschild is a registered dietician, PhD, and research associate at Sports Performance Research Institute New Zealand. Ever been curious about the science behind fueling your athletic performance? Look no further, as we are joined by Jeff Rothschild, a registered dietitian and researcher, who is here to break down the complex concept of carbohydrate periodization for trail and ultra runners. We dissect the misunderstood principle of "fueling for the work required" and dive into how an athlete can manipulate their carbohydrate intake during periods of high intensity or high training loads. Jeff's innovative research on this topic unveils an index for quantifying carbohydrate periodization - a game-changer for athletes aiming to enhance their performance through optimized nutrition. Episode highlights: (17:32) Calculating periodization: any metric of training load, daily carbohydrate intake in g/kg, correlation coefficient, reasons for including range and monotony (36:24) How to track your carbohydrate periodization: track your diet, consistent measures of training load, TSS or CR100, TSS is best, use the spreadsheet in the description, help from Jeff’s app (43:38) Use cases for carb periodization: predicted TSS for your upcoming workout, adjusting carbohydrate intake based on each day, you can consume more after the workout if the true TSS was higher than expected, examples Additional resources: The quantification of daily carbohydrate periodization among endurance athletes during 12 weeks of self-selected training: presentation of a novel Carbohydrate Periodization Index Jeff’s app-https://rothschild.shinyapps.io/carb-index-app/ SUBSCRIBE to Research Essentials for Ultrarunning Buy Training Essentials for Ultrarunning on Amazon or Audible. Information on coaching-https://www.trainright.com Koop’s Social Media: Twitter/Instagram- @jasonkoop