Your library / The body · ninety days

Longevity

The complete Longevity reading: the six pillars in the order the body needs them, the six numbers you take on day one, and all ninety days written out — sleep, energy, strength, recovery, food, and the reason you get up.

By Seçil Sayhan14 chaptersLongevity · the library

[ The reading ]

01Pillar 1 — Metabolic Health

Chronological age predicts little; biological age predicts almost everything. The honest map of where you stand — and the six Day-1 numbers you will re-run on Day 85.

10 min read
02Pillar 2 — Movement

Cardiorespiratory fitness is among the strongest predictors of how long you live. How to estimate yours, the zones that build it, and the interval protocol that raises it fastest.

9 min read
03Pillar 3 — Recovery

Sleep is when the brain literally washes itself and the body repairs. Short sleep raises risk across nearly every disease of aging. The five-variable protocol that fixes it.

8 min read
04Pillar 4 — Nutrition

Most adults eat half the protein they need to hold muscle as they age. The target, the leucine threshold, and why distributing it across the day matters more than the total.

8 min read
05Pillar 5 — Connection & Integration

Social isolation carries mortality risk comparable to smoking, and isolation gets under the skin biologically. The connection audit that exposes the gap most achievers ignore.

10 min read

[ The ninety days ]

06Days 1–10

The clock. The Baseline · The Clock Starts at Waking · Morning Light, the Free Drug…

14 min read
07Days 11–20

The clock. The Nap Question · The Wind-Down Sequence · The Regularity Audit…

14 min read
08Days 21–30

The fuel. The Early Signal · Breakfast Does the Heavy Lifting · The Ultra-Processed Swap…

15 min read
09Days 31–40

The engine. Recovery Is Training · The Only Rule · The Boring Base…

14 min read
10Days 41–50

The engine. Zone Two, Outside · Halfway — Look at the Data · Strength Comes Fast…

15 min read
11Days 51–60

The engine. First Intervals · The Step Floor · Eight Sessions…

16 min read
12Days 61–70

The brake. Connection Is Biology · The No-Input Walk · Recovery's Quiet Scoreboard…

15 min read
13Days 71–80

The dashboard. The Dashboard Opens · Find the Crash Trigger · Find the Peak Window…

16 min read
14Days 81–90

The dashboard. Never Miss Twice · Protocol Card, Final · The Covenant…

15 min read

14 chapters, about 36,000 words. Chapters open with the email you bought Longevity with. Not in yet?

Download the whole book

Sign in with the email you purchased with. The book stays with you.

Don’t have it yet? Get Longevity →
The whole thing

Download Longevity — the complete text
14 chapters, about 36,000 words. Lifetime access; the link still works after the ninety days end.