September 29, 2026 · 12 MIN
Fasted Zone-2 Training for Fat Adaptation: What the Evidence Actually Shows
Fasted zone-2 training increases fat oxidation rates to 0.5-1.0 g/min versus 0.3-0.7 g/min when fed. Measurable adaptations appear after 3-4 weeks of consistent fasted sessions through AMPK-mediated mitochondrial biogenesis. However, the evidence is clear that fat adaptation does not improve threshold or high-intensity performance, and certain populations should avoid this approach entirely.
