Live Well Be Well with Sarah Ann Macklin | Health, Lifestyle, Nutrition How Do You Know You’re in Zone 2? Finding the Right Training Intensity Without a Wearable | Inigo San Milan | Be Well Moments
Dec 29, 2025
Inigo San Milan, an exercise physiologist specializing in metabolic physiology, shares insights on identifying Zone 2 training intensity without wearables. He explains the talk-test method and how it relates to lab measurements. Inigo addresses common misconceptions, revealing that exercising at too high an intensity can hinder fat oxidation and weight loss. He emphasizes the importance of balancing Zone 2 training with recovery for improved mitochondrial function and long-term fat burning. Tune in for practical tips on effective fat loss!
AI Snips
Chapters
Transcript
Episode notes
Find Zone 2 With The Talk Test
- Use the talk test to find Zone 2: you can speak but only with effort and not comfortably.
- If you cannot sustain a conversation for more than a few seconds, you are already at very high intensity.
Zone 2 Is The Fat Oxidation Sweet Spot
- At Zone 2 you burn both glucose and fat, and this is where fat oxidation peaks (fat max).
- As intensity increases, fat oxidation falls to zero because muscles need faster ATP supplied by carbohydrates.
Breathing Reveals Metabolic Fuel Use
- Higher intensities force breathing and lactate buffering, which reduces fat burning.
- Faster breathing while speaking signals carbohydrate-dominant metabolism and suppressed fat oxidation.