Zone 2 Training
The magic of Zone 2
Zone 2 is 60-70% of max heart rate — a conversational pace. You're primarily burning fat and building mitochondria.
Mitochondrial density
Zone 2 training is the most effective way to increase mitochondrial density. More mitochondria = more energy, better fat burning, and slower cellular aging.
True or False
High-intensity training builds more mitochondria than Zone 2.
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The talk test
Match each zone to its description.
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The Attia prescription
Dr. Peter Attia recommends 3-4 hours of Zone 2 per week as the foundation, plus 1 session of high-intensity intervals. This combo maximizes both mitochondrial density and VO2 max.
Key Takeaway
Aim for 150-180 minutes of Zone 2 per week — the most evidence-backed exercise prescription for longevity.