Zone 2 Cardio

Sustained aerobic exercise at 60–70% of maximum heart rate — the intensity where you can hold a full conversation. The cornerstone of Dr. Peter Attia's longevity protocol. Builds mitochondrial density, the single most important biomarker for long-term health.

Why this habit matters

Physical: Builds mitochondrial density (strongest longevity biomarker), improves fat oxidation, cardiovascular remodeling, insulin sensitivity on par with medication.
Mental: Sustained BDNF production reduces dementia risk; steady-state exercise is meditative and stress-reducing.
Productivity: Metabolic flexibility from Zone 2 means sustained energy without crashes; improved fat burning reduces reliance on glucose spikes.