Rhonda Patrick and Peter Attia are two of the most rigorous thinkers in longevity science, and when they agree on something, it's worth paying attention. Their shared frustration here is with a number that's become gospel in nutrition circles — 0.8 grams of protein per kilogram of body weight. That RDA was established using nitrogen balance studies, which measure protein loss through urine and sweat. It sounds precise. It isn't. What those studies captured was the minimum needed to prevent obvious deficiency, not the amount needed to actually maintain muscle tissue over decades of living.
The distinction matters enormously. The RDA for protein was never designed to be a longevity target. It was designed to prevent clinical protein malnutrition. And yet, it's what most people — and most healthcare providers — treat as sufficient. It isn't. For adults who want to age with physical capability intact, 1.2 grams per kilogram is closer to the real baseline.
Here's where aging makes everything harder. When you're young, your muscles are sensitive. Eat protein, do some exercise, and the anabolic signal is strong — muscle protein synthesis fires reliably. As you age, that sensitivity diminishes. You have to do more to get the same response. This is anabolic resistance, and it's one of the more sobering mechanisms in the longevity literature. The body doesn't lose the ability to build muscle — it just becomes more reluctant, requiring a stronger stimulus to respond.
The research Rhonda cites is clear: older women consuming 1.2 grams per kilogram are 30% less likely to experience frailty. That's not a marginal effect. Frailty is one of the strongest predictors of mortality in older adults, and protein intake is a modifiable variable. The tragedy is that most older adults are eating well below this threshold while also becoming less physically active — a compounding problem.
This is the connection that doesn't get discussed enough. Across the knowledge base — and particularly in Rhonda's own work on hyperthermic conditioning — we see that heat exposure activates heat shock proteins, molecular chaperones that prevent misfolded proteins from aggregating. But there's another layer: heat stress upregulates growth hormone and sensitizes muscle tissue to anabolic signals. In other words, regular sauna or contrast therapy may actually help counter anabolic resistance. You're not just relaxing. You're priming your muscles to respond more efficiently to the protein you eat afterward.
The protocol I'd suggest: resistance training two to three times weekly, 1.2 grams of protein per kilogram of body weight distributed across meals, and thermal stress — sauna or contrast sessions — as a recovery and sensitization tool. The sauna and the protein aren't separate strategies. They reinforce each other at the cellular level.
Eat more protein than you think you need. Move your body with intention. And use heat and cold not just for recovery, but as tools that make everything else you're doing more effective. That's not a supplement stack. That's a system.