How to determine your maximal sustainable intensity (second threshold) | #21 ft. Dr. Robert Jacobs

This episode of the Critical Oxygen podcast discusses the concept of thresholds in exercise physiology. Dr. Robert Jacobs and I explore the confusion surrounding thresholds and the various ways they are measured. We also discuss the limitations of lactate testing and the disconnect between research and real-world application. The practical application of thresholds in training and competition is explored, as well as their relevance for beginners. The episode concludes with a discussion on the critical power model and its implications for sustainable exercise intensity. TAKEAWAYS 1) Second threshold is used to define the delineation between sustainable and unsustainable exercise intensity. 2) Lactate testing has limitations and should be used in conjunction with other measures. 3) Practical application of thresholds in training and competition requires individualization and a focus on pacing. 4) Critical power is a mathematical model that represents the maximum sustainable power output an individual can maintain for an extended period of time. 5) The critical power model has limitations and may overestimate an individual's sustainable power output. 6) Consistency in testing and measuring physiological variables is crucial for tracking changes in performance.Articles: The critical power concept - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5371646/Maximal metabolic steady state - https://physoc.onlinelibrary.wiley.com/doi/full/10.14814/phy2.14098Don't forget to subscribe to get notified when new episodes are released. If you have a question or topic you want us to address, leave a comment!Follow Phil on Instagram - https://www.instagram.com/criticalo2Interested in testing, courses, or other long form content check out the critical oxygen website - https://www.criticaloxygen.com OUTLINE 00:00 Introduction to Thresholds 03:22 Confusion around Thresholds 08:20 Thresholds and Exercise Duration 13:09 Limitations of Lactate Testing 17:06 The Disconnect between Research and Real-World Application 19:26 Maximal Lactate Steady State 22:47 Steady State Isn't Steady 26:32 Practical Application of Thresholds in Training 34:13 Thresholds in Competition 41:33 Thresholds for Beginners 44:28 The Critical Power Model 50:19 Understanding Critical Power 51:45 Challenges of Maintaining Critical Power 52:18 Factors Affecting Critical Power 56:30 Physiological Models for Performance 57:25 The Impact of Hydration and Nutrition 59:16 Individual Variability in Performance 01:01:13 Optimizing Training Zones 01:04:32 Performance as a Sine Wave 01:06:29 Limitations of the Critical Power Model 01:07:16 Caveats of Time to Exhaustion Trials 01:08:14 Alternative Testing Methods 01:09:13 Consistency in Testing