Overview
Zone 2 (nose-breathing/conversational pace, ~60–70% max HR) trains mitochondrial function and fat oxidation. Rucking (walking with weight) is an accessible Zone 2 modality that adds strength stimulus.
Treatment
Aim for 150–240 min/week of Zone 2. Add 1–2 higher-intensity (VO2 max) sessions. Strength train 2–3x/week. This combination has the strongest longevity evidence.