Anyone who has coached or competed in CrossFit for awhile sees things that kind of don’t make sense. Athletes with 15+ unbroken ring muscle-ups and a 6:30 2k row who are surprisingly bad at “metcons.” Athletes who can only do 5-10 unbroken strict handstand push-ups who are able to quickly chip away at a set of 50 and beat athletes who can do 20+ unbroken reps. Evan Peikon from Training Think Tank has done a lot of work with the Moxy unit on measuring muscle oxygen saturation and blood flow, and he’s developed a model that is able to explain a lot of these seemingly confusing contradictions in performance. While this conversation gets a bit into the weeds, a lot of these details are necessary to understand the complexity of fatigue in CrossFit as a sport. If you’ve ever seen something that doesn’t make any sense in CrossFit, Evan’s framework may give some insight into what’s actually going on with different “types” of athletes. Check out more from Evan and Training Think Tank here: Instagram: @evan_peikon | @trainingthinktank Website: Evan’s Interviews and Articles | www.trainingthinktank.com YouTube: @trainingthinktank If you're not already subscribed to our newsletter, head over to www.legionsc.com and get with the program. You can follow us on Instagram as well for regular training tips and crunchy tactics: @legion.sc Show Notes: [01:10] Evan’s opinions on metalcore [10:55] The basic physiology of oxygen delivery and what different measures like VO2 max, muscle oxygen saturation and heart rate can tell us about performance [16:58] What are different types of fatigue that can occur at the muscle level? And – the 3 different types of limiters in CrossFit athletes. [23:35] What is the difference between Evan’s model of fatigue based upon his work with muscle oxygen saturation and more traditional models of fatigue based upon acidosis? [31:45] What is happening when athletes feel “burning” in the muscle vs when athletes feel a “pump” in the muscle? How do these sensations in the muscle create global feelings of fatigue? What role does the “mind” play in governing our effort? [41:44] Psychological gamesmanship in racing – particularly in track athletes [45:00] What role do occlusions play in creating fatigue for athletes in CrossFit? And – the 2 different types of occlusion and what those mean for your ability to “push through.” [01:03:40] Why do some people always have one specific muscle group “blow up” – like their grip, their shoulders, their low back, their calves, etc. [01:09:23] How can athletes who tend to get muscle pumps improve their ability in CrossFit? What would an ideal training session look like for this athlete – and why do some common training protocols potentially make this kind of athlete worse? [01:17:25] What does Evan think the most common limiting factor is for athletes who do not tend to occlude in their muscles? These athletes often struggle to build strength – how should they structure their strength training protocols so they can actually get stronger? Links and Resources Mentioned Norma Jean Josh Scogin Cory Brandan Norma Jean – Redeemer The Chariot CTP Underoath Slipknot Pound Classes What is muscle oxygen saturation? NIRS(Near-infrared spectroscopy) Moxy Monitor VO2 max The Phosphocreatine System Anaerobic glycolysis Cellular respiration Energy system utilization chart Bicarbonate buffer system 5-1-5 Step Test Improvements in Cycling Time Trial Performance Are Not Sustained Following the Acute Provision of Challenging and Deceptive Feedback Max El Hag Travis Mayer James Jowsey