I'm optimizing for a Tuesday in 2050
When my oldest is my age, I'll be in my early eighties. Once you do that math you can't undo it. It changes what fitness is for.
Issue #11 · Jul 18, 2026 · 4 min
Longevity is compound interest for the body. Most of what determines whether the next four decades feel like a slow climb or a slow decline gets decided by dozens of small choices repeated across years, not by any single intervention. These notes are about the choices worth compounding - and the ones that only look important.
When my oldest is my age, I'll be in my early eighties. Once you do that math you can't undo it. It changes what fitness is for.
Issue #11 · Jul 18, 2026 · 4 min
Before surgery I ask what sounds like small talk: can you climb two flights of stairs without stopping? The answer predicts more than almost anything else.
Issue #6 · Jun 13, 2026 · 4 min
Two 84-year-olds, same surgery, same morning. One walked in and cut his own grass. The other took three of us to move. The gap wasn't luck; it was thirty years.
Issue #5 · Jun 6, 2026 · 4 min