A closer look
Gasping for air during a high-intensity workout actually shuts down your body's ability to build elite metabolic engines. Longevity expert Peter Attia emphasizes that sustained, painfully boring Zone 2 training is the only way to stimulate mitochondrial biogenesis. By keeping your heart rate in a specific, conversational threshold, you literally force your cells to build new mitochondria that burn fat for fuel instead of relying on cheap glucose.






