Longevity

seedlongevity

Notes on longevity and health, written for a specific phenotype the standard playbook tends to undershoot.

Who this is for

Turning 40 (or in the 35–45 window broadly)
15–20+ years of distance running including ultras (10-hour races, sub-3:20 marathons)
Lean build: low body fat, BMI ~20–22, around 64 kg / 181 cm
Cardiovascular base well above average; low resting HR; VO2 max already high relative to peers
Splits time across countries (here: Korea and India)
Single, no current plans to marry
INTP-style — analytical, prefers solo deep work
Senior knowledge-work day job
Already running, biking, climbing, doing some calisthenics and dumbbells; learning Korean; planning to add piano

The standard longevity advice — lift, cardio, sleep, social, scans, learn things — is correct but generic. For this profile some interventions are higher-leverage, others (like extreme fasting) are actually counterproductive. The pages below try to be specific about which and why, with actual numbers attached.

Activity priorities

Activity ROI for Longevity — ranking of common activities (lifting, cycling, piano, language, bouldering, yoga, running, etc.) by what they actually buy for the next 40 years.

Strength and lifting

Strength Targets for Lean Athletes — the “pink dumbbell trap,” and specific weight × rep targets for goblet squat, RDL, rows, chest press for a 64 kg frame.
Bone Density for Lean Runners — why lean ultra-runners have low spine/hip density and the three specific inputs (axial loading, plyometrics, rate-of-loading) that fix it.
Unilateral Lifts for Fall Prevention — single-leg work that prevents the 70s-era fall, with exact exercises and weights.
Heavy Slow Resistance for Tendons — the Kongsgaard/Magnusson protocol for tendon armour, with tempo and weight specifics.
Four Horsemen Functional Tests — Attia’s four benchmark tests with targets at 40, 60, and 80.

Cardio

VO2 Max Intervals on Smart Bike — the Wisløff 4×4 protocol with specific HR zones and RPM targets.

Eating

Hardgainer Eating Strategy — why lean runners can’t gain weight on chicken-and-broccoli, with the high-calorie protein shake recipe and the 300-kcal surplus method.
Time-Restricted Eating vs OMAD — why fasting works for sedentary people and is actively dangerous for lean endurance athletes.
Supplement Stack for Endurance Athletes Past 40 — D3, K2 (MK-7), magnesium, creatine, omega-3 with specific doses.

Recovery and environment

Heat Exposure Protocol — sauna evidence plus a home hot-bath variation with specific temperature, duration, frequency, and the Epsom-salt question.
Air Quality Protection — HEPA, AQI thresholds, masks; specifically for someone splitting Korea and India.

Oral, hearing, vision

Oral Microbiome and Mouthwash Paradox — why standard mouthwash sabotages the beetroot-juice nitric-oxide pipeline. Water flosser brand picks.
Headphone Safety for Athletes — the 60/60/10 rule, swamp effect, why bone-conduction at max volume still damages hearing.
Hearing Restoration Pipeline — current gene-therapy and stem-cell pipeline, costs, India availability.

Preventative testing

Preventative Health Panel at 40 — DEXA, ApoB, Lp(a), fasting insulin, vitamin D, the full biomarker dashboard.
Less-Discussed Health Checks at 40 — sleep apnea, hormone baselines, skin checks, pelvic floor, periodontal disease.