How to Create Custom Workouts & Race Plans
Learn what every button and setting does in the ZoneTrainer workout builder: Single Workout mode, 10K negative split presets, strict BPM ceilings, distance intervals, and multi-week plans.
Aerobic Decoupling & Cardiac Drift
Learn why your heart rate drifts upward at a steady pace, how to calculate Joe Friel's 5% decoupling benchmark, and how to audit your Strava/TCX runs without a lab test.
Karvonen Formula vs Tanaka & 220-Age
Stop relying on inaccurate 220-Age formulas with a ±12 BPM error margin. Discover how factoring in Resting Heart Rate (HRR) calculates your true physiological Zone 2 aerobic threshold.
The Aerobic Black Hole Trap
Are you running hard every day but stagnating? Explore Dr. Stephen Seiler's polarized 80/20 research and learn why slowing down in Zone 2 is the secret to getting faster.
Dr. Iñigo San Millán & Peter Attia Zone 2 Guide
Deep dive into Type I slow-twitch muscle fiber recruitment, MCT1 lactate transporters, FatMax oxidation, and how to calibrate your Zone 2 ceiling without a blood lactate meter.
BLE Chest Straps vs Optical Wrist Watches
Why optical PPG watches suffer from cadence lock in Zone 2, how ECG chest straps (Polar H10, Garmin HRM, CooSpo) compare, and how to pair them 100% offline on Android.