Regularly practice Zone 2 training, defined as the maximum intensity that allows for maintaining a blood lactate level at or below 2 mmol/L.

holds up

Science strongly supports the idea that Zone 2 training improves metabolic flexibility and mitochondrial function.

noli's read

Science strongly supports the idea that Zone 2 training improves metabolic flexibility and mitochondrial function. Meta-analyses and observational studies (e.g., the work of San Millán and research on cardiorespiratory health) confirm that this intensity promotes fat oxidation and increases mitochondrial density. Peter Attia rightly emphasizes that this improves overall energy efficiency and metabolic longevity. There is no exaggeration here; it is a well-documented pillar of exercise physiology. Unlike more intensive methods, this practice is safe and accessible, which reinforces its relevance for long-term health. Research largely validates this 2 mmol/L threshold as a reliable marker of aerobic efficiency.

the sources

Claimed by Peter Attia. Noli grades the claim, never the person.

Decoded by Noli · July 18, 2026 · the original post

What the graded evidence says

Evidence: B

Effect: mindfulness meditation vs active control on anxiety, depression, pain, and attention (meta-analysis of RCTs) — anxiety effect size 0.38 (95% CI 0.12-0.64) at 8 weeks; depression 0.30 (0.00-0.59); pain 0.33 (0.03-0.62); low/insufficient evidence for effects on attention
Measured on: diverse adult clinical populations

Effects on stress and mood are small-to-moderate; the evidence that meditation improves attention or concentration specifically is weak. It was not better than other active treatments like exercise or therapy.