Jem Arnold is a physiotherapist, coach and PhD student. Currently, his main research focus is investigating FLIA: blood flow limitation of the iliac artery, a condition that affects certain athletes even at the very elite level, sometimes with surgery as the end outcome. Jem is also very involved and knowledgeable in using NIRS (near-infrared spectroscopy) to measure muscle oxygen saturation (SmO2). We dive deep into how using NIRS and SmO2 can inform workout execution as well as training interventions and athlete profiling.     IN THIS EPISODE YOU'LL LEARN ABOUT: -What is NIRS and what is muscle oxygen saturation?  -The balance of oxygen delivery (to the capillaries surrounding muscle tissue - supply) and extraction (by the muscles from the capillaries - demand) -NIRS testing protocols, and how it relates (and does not relate) to oxygen uptake (VO2) and lactate measurments -Using NIRS to profile athletes  -Using NIRS in high-intensity workouts to optimise interval execution  -Blood flow limitation of the iliac artery (FLIA) - what is it, and what is its prevalence among athletes -Risk factors for FLIA -Current detection and diagnosis methods of FLIA, as well as treatment options -How Jem's research aims to find methods by which FLIA detection can be improved SHOWNOTES: https://scientifictriathlon.com/tts358/ SCIENTIFIC TRIATHLON AND THAT TRIATHLON SHOW WEBPAGE: www.scientifictriathlon.com/podcast/ SPONSORS: ROKA - Exceptional quality triathlon wetsuits, trisuits, swimskins, goggles, performance sunglasses as well as prescription eyeglasses and sunglasses.  Online vision test for prescription updates and home try-on options available for eyeglasses. Ships from the US, UK and EU. Trusted by world-leading athletes such as  Lucy Charles-Barclay, Javier Gómez Noya, Flora Duffy, Morgan Pearson, Summer Rappaport and others in triathlon, cycling, speed skating, and many more. Visit roka.com/tts for 20% off your order. ZEN8 - The ZEN8 Indoor Swim Trainer is a unique swim bench that allows you to improve technique, power, and swim training consistency. With the trainer you can do specific power and technique work, including working on your catch and your core activation, and it makes it easier to stay consistent even when you can't go to the pool. Get the special Zen8 x TTS bundle including the swim bench and a number of Zen8 training plans and on-demand workouts on zen8swimtrainer.com/tts. LINKS AND RESOURCES: Jem's Twitter, email, and his blog Sparecycles Muscle Oxygen Saturation (SmO2) with Roger Schmitz | EP#85 What types of intervals are most effective? A scientific analysis with Michael Rosenblat | EP#243 Applied triathlon science with Olav Aleksander Bu (Norwegian Triathlon Olympic team) | EP#264 Moxy - well-established NIRS device Train.Red - another NIRS device also used and recommended by Jem Comparing the Respiratory Compensation Point With Muscle Oxygen Saturation in Locomotor and Non-locomotor Muscles Using Wearable NIRS Spectroscopy During Whole-Body Exercise - Yogev et al. 2022 A longitudinal study on the interchangeable use of whole-body and local exercise thresholds in cycling - Caen et al. 2022 Thresholds, Constructs, and Confidence Intervals - blog post by Jem Why is there Two Different Moxy Monitor SmO2 Profiles? w/ Jem Arnold - UTH1 - Upside Strength Podcast Maxima MC self-check questionnaire for FLIA (flow limitation of the iliac artery) Short- and long-term results of operative iliac artery release in endurance athletes - van Hooff et al. 2022 Rejuvenated and recharged: Tayler Wiles eyeing return to the pro peloton after surgery - Velonews article Feature: Arterial disease and cycling - Velonews article Cyclists' Iliac Syndrome - Interest group - Facebook group Cyclist Alliance - List of international vascular specialists with experience in FLIA RATE AND REVIEW: If you enjoy the show, please help me out by subscribing, rating and reviewing: www.scientifictriathlon.com/rat