Zone 2 Cardio

Zone 2 is the least glamorous, highest-ROI training you can do, and almost nobody does enough of it. Conversational pace — you can hold a sentence, barely — for 45 to 60 minutes, three to four times a week.

This is the base everything else is built on: mitochondrial density, fat oxidation, a heart that does more with less. It's an investment in your forties and fifties, banked in your thirties. Boring, repeatable, non-negotiable. Titan standard.