In this episode of the Critical Oxygen podcast, I am joined again by Dave Schell where we discuss field tests for determining training zones. We emphasize the importance of understanding the purpose of training zones and the physiological thresholds that bound them. We suggest using simple field tests to estimate zones, such as nose breathing or the talk test for zone 2, and iterative workouts or subjective efforts for threshold and VO2 max zones. We also highlight the need for consistency in workouts to track progress and avoid overcomplicating training. TAKEAWAYS - Understanding the purpose the physiological thresholds and the zones they bound is crucial for effective training. - Simple field tests, such as nose breathing or the talk test, can be used to estimate zone 2. - Iterative workouts or subjective efforts can help determine threshold and VO2 max zones. 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/ CHAPTERS 00:00 Introduction and Purpose of Training Zones 06:17 Threshold and VO2 Max Zones: Iterative Workouts and Subjective Efforts KEYWORDS field tests, training zones, physiological thresholds, zone 2, threshold, VO2 max, nose breathing, talk test, iterative workouts, consistency