In this episode of Fast Physiology on the Critical Oxygen Podcast, Dave Schell and I discuss the concepts of cardiac drift and physiological decoupling. We explore how heart rate responds to prolonged exercise, the physiological mechanisms behind these phenomena, and practical training strategies to mitigate the effects of cardiac drift. The conversation emphasizes the importance of hydration, heat tolerance, and consistent training for endurance athletes. TAKEAWAYS 1) Cardiac drift refers to the increase in heart rate at a steady power output over time. 2) Decoupling compares heart rate to power output, indicating fatigue resistance. 3) Hydration and cooling are crucial for maintaining performance during exercise. 4) Training in specific conditions can help athletes adapt to different environments. If you have a question or topic you want us to address, leave a comment! Follow Phil on Instagram - https://www.instagram.com/criticalo2 Follow Dave on Instagram - https://www.instagram.com/kaizenendurance/ OR YouTube - https://www.youtube.com/@UCT5Cy95BiLIDQh4KS5bohhQ Interested in Gravel or Mountain Bike Coach? Head to Dave's website - https://www.kaizenendurance.coach/ Want to learn more physiology, check out my blog, and courses - https://www.criticaloxygen.com/ CHAPTERS 00:00 Introduction 01:04 Understanding Cardiac Drift and Decoupling 10:31 Physiological Mechanisms Behind Cardiac Drift 19:08 Practical Applications and Training Strategies 24:09 Conclusion and Future Topics KEYWORDS cardiac drift, physiological decoupling, endurance training, heart rate metrics, exercise physiology, VO2 max, hydration, heat tolerance, performance optimization, fitness