ketOntrack

🚨👋I’m launching a Substack to write about metabolism, sports performance, mitochondrial function, metabolic health, cancer metabolism, longevity... I’m starting with two pieces!. The first addresses the recent review “Much Ado About Zone 2.” My position is simple: the debate between Zone 2 and HIIT is largely artificial. In real training environments, both intensities coexist and always have. The second article explains the physiology behind Zone 2, something that is often simplified or misunderstood. Zone 2 is not just a training label. It reflects a specific metabolic state defined by redox balance, mitochondrial flux, and lactate shuttle equilibrium. Thirty years working with elite athletes and metabolic patients led me to this framework. Links below: Article 1 — Why the Zone 2 vs HIIT debate is largely misguided inigosanmillan.substack.com/… Article 2 — The cellular physiology that actually defines Zone 2 inigosanmillan.substack.com/… If this topic and others interests you, feel free to subscribe. I’ll be writing regularly about metabolism, performance, metabolic health, mitochondrial function, cancer metabolism...Thank you!😉

For about a decade, I’ve been showing these two slides at conferences. Two hunter-gatherer populations (Hadza and Tsimane), likely the closest living humans to our Paleolithic ancestors. Diet: • 65–70% carbohydrates • 15-20% protein • 10–15% fat • ~13% lower daily caloric intake than the US population Daily movement: • 115–135 minutes per day • 6–12 km of walking Health outcomes: • Obesity: ~2% • Type 2 diabetes: ~1% • Cardiovascular disease: among the lowest ever observed This is not a low-carbohydrate population. The difference is metabolic fitness. When mitochondria are continuously stimulated by daily movement, carbohydrates can be oxidized (burnt). When movement disappears, fuel oxidation fails and metabolic disease emerges. The debate should not be low-carb vs high-carb. That debate has failed to solve obesity or type 2 diabetes for decades. The real question is: Can your mitochondria still do their job? #MitochondrialFunction #MetabolicFitness #MetabolicFlexibility #PhysicalActivity

Everyone wants the shortcut to longevity. Pills, powders, boosters, activators, molecules that promise to “hack” aging. But let’s be honest: 👉 There’s no solid scientific evidence that almost any of these supplements extend human lifespan or healthspan. Most studies are mechanistic, in mice, or rely on surrogate markers, not real-world outcomes. And here’s the paradox: The people who live the longest on this planet have never heard of NMN, NAD⁺, or rapamycin. They walk daily, eat natural unprocessed food, have purpose, strong community ties and low chronic stress. Longevity doesn’t come from a capsule. It comes from metabolic health, movement, connection, and consistency; the same foundations that modern science is still trying to replicate in pill form. Longevity isn’t hacked. It’s earned.