Beyond Heart Rate: 7 Common Mistakes in Zone 2 Training (And How to Fix Them)

This video challenges the common advice that the biggest Zone 2 training mistake is simply going too hard. It argues that for many runners, especially those over 40, seven other lesser-known mistakes are more detrimental to progress. The goal is to help runners optimize their Zone 2 training by understanding and avoiding these pitfalls.

Central Theme: Effective Zone 2 Training Beyond Basic Heart Rate

The core message is that true Zone 2 effectiveness relies on a nuanced approach that goes beyond just heart rate numbers. It emphasizes understanding physiological markers (or their proxies), proper duration, progressive volume, intensity accuracy (not too hard, not too easy), session purity, and adequate fueling.

Key Mistakes and Solutions:

1. Treating Zone 2 Heart Rate (HR) as Infallible:
   • Mistake: HR is only a proxy for true Zone 2 (defined by lactate threshold LT1 & fat/carb crossover) and is highly variable (caffeine, sleep, stress, age).
   • Solution: Complement HR with the talk test (speak full sentences) and Rate of Perceived Exertion (RPE 4-5/10). Lab lactate testing is the gold standard.
2. Over-relying on Wearables & Generic Formulas:
   • Mistake: Device-estimated Zone 2 ranges and formulas (e.g., MAF 180) can be inaccurate as they don’t account for individual max HR, physiology, or sport.
   • Solution: If using formulas, try to get an accurate max HR. Prioritize talk test and RPE.
3. Underestimating Minimum Session Duration:
   • Mistake: Sessions under 30 minutes are often too short for meaningful adaptation, as fat metabolism takes ~15 minutes to ramp up.
   • Solution: Aim for 30+ minute sessions (45-90 mins for trained individuals). Fewer, longer sessions are better than many short ones if time-crunched.
4. Mismanaging Training Volume (Too Little or Too Much Too Fast):
   • Mistake: Insufficient volume yields poor results; rapid increases, especially for over-40s, risk overuse injuries as connective tissues adapt slowly.
   • Solution: Employ progressive overload. Use the 10% weekly increase rule as a guideline, but primarily listen to your body.
5. Going Too Easy:
   • Mistake: Training significantly below LT1 (in Zone 1) doesn’t provide the same adaptive stimulus as genuine Zone 2.
   • Solution: Ensure effort is challenging enough to be in Zone 2—the highest intensity sustainable before significant lactate build-up—but still conversational.
6. Mixing Intensities During Zone 2 Runs:
   • Mistake: Adding high-intensity bursts (sprints, pre-run gym) disrupts steady aerobic metabolism, spikes lactate, and wastes effective Zone 2 time.
   • Solution: Keep Zone 2 runs “clean.” Separate high-intensity sessions by at least 3 hours, or do Zone 2 work first.
7. Underfueling for Zone 2 Runs:
   • Mistake: Believing fasted Zone 2 enhances fat burning; it can actually impair performance, adaptation, and hormonal balance. Fat burning improves with more/better mitochondria, not fasting.
   • Solution: Fuel adequately before Zone 2 runs (e.g., 10-15g protein, 70-100g carbs for a 1-1.5hr run) to support training and mitochondrial development. Achieve fat loss via overall daily caloric deficit.

Key Conclusions & Takeaways:

The video concludes that effective Zone 2 training is personalized, consistent, and accurately executed, demanding an understanding beyond mere heart rate numbers. By addressing these seven common mistakes—particularly concerning intensity perception, duration, volume progression, session structure, and fueling—runners can significantly enhance their aerobic base, improve performance, and minimize injury risk, especially those over 40.

Source: 7 Zone 2 mistakes runners over 40 must avoid