Every pillar on this site uses terms that don’t get defined on first use, because the post that introduced them assumed you’d look it up. This page is that lookup. Plain-language definitions for the recurring biomarkers, nervous-system terms, and site-coined concepts — nothing here is medical advice, just a shared reference.
Precision Longevity terms
ApoB (Apolipoprotein B) — A protein found on every artery-clogging lipoprotein particle in your blood. Because it counts particles rather than the cholesterol packed inside them, many cardiologists consider it a more direct measure of cardiovascular risk than standard LDL cholesterol.
hs-CRP (high-sensitivity C-reactive protein) — A blood marker of low-grade, chronic inflammation. Unlike the CRP test used to catch acute infections, the “high-sensitivity” version is sensitive enough to flag the quiet, long-running inflammation linked to cardiovascular and metabolic disease.
Sarcopenia — The age-related loss of muscle mass and strength. It’s gradual, often invisible on a scale, and the reason “muscle as a retirement plan” shows up repeatedly across Precision Longevity content — strength is what keeps independence intact later in life.
Grip strength — A simple, low-tech proxy for overall muscular and functional health, often used in research as a predictor of broader health outcomes because it correlates with total-body strength and physical resilience.
SHBG (sex hormone-binding globulin) — A protein that binds circulating testosterone and estrogen, making them biologically inactive while bound. SHBG rises with age, which is why “total testosterone” alone can be a misleading number without it.
Hypogonadism — The clinical term for low testosterone. Diagnosing it requires both a consistently low lab result and real symptoms — a low number alone, with no symptoms, isn’t a diagnosis.
STRAW+10 — The medical framework doctors use to stage perimenopause and menopause, based on menstrual cycle changes and hormone markers rather than symptoms alone.
Timing hypothesis — The finding that hormone replacement therapy’s cardiovascular risk depends heavily on when a woman starts it relative to menopause — lower risk starting within 10 years of menopause and under age 60, higher risk starting later.
Bioidentical hormones — Hormone formulations molecularly identical to what the body produces. The word describes chemical structure, not a different safety profile — compounded “bioidentical” products also skip the dosing consistency and safety monitoring FDA-regulated products go through.
MACE (major adverse cardiac events) — The standard trial endpoint for serious heart problems (heart attack, stroke, cardiovascular death) used to measure a treatment’s cardiovascular safety.
Somatic Resilience terms
Vagal tone — A measure of how responsive your vagus nerve is — the nerve most responsible for shifting your body out of “fight or flight” and into rest-and-digest mode. Higher vagal tone is generally associated with faster recovery from stress.
HRV (heart rate variability) — The variation in time between consecutive heartbeats. Counterintuitively, more variability is the healthy sign — it reflects a nervous system that can flexibly shift between stress and recovery states rather than staying locked in one.
Orthosomnia — Anxiety about sleep caused by obsessively monitoring sleep-tracker data. The tracker becomes the source of the sleep problem it was meant to solve.
Cyclic sighing — A breathing pattern (a double inhale through the nose followed by a long exhale) studied as a fast way to shift the nervous system toward calm, distinct from generic “deep breathing.”
Downstate / Upstate — Site shorthand for your nervous system’s recovery mode (downstate) versus its activated, performance mode (upstate). The core Somatic Resilience thesis is that both states need to be deliberately engineered, not left to chance.
Cognitive Sovereignty terms
Digital Sovereignty — Site-coined term for setting the terms of your relationship with technology deliberately, rather than defaulting to whatever a notification, feed, or app is optimized to make you do.
Attention residue — The cognitive trace left behind when you switch tasks, even briefly. It measurably degrades performance on whatever you turn to next — the underlying reason “just glancing” at a notification isn’t free.
Cognitive Sovereignty — The pillar name for treating focus as a finite, defendable resource rather than something that should be available to any app or notification that asks for it.
Cross-pillar terms
Vitality Span — Site-coined alternative to “lifespan” or “healthspan” — the stretch of years you’re not just alive, but capable of doing the things that make life worth extending in the first place.
Tactical Health Infrastructure — The site’s framing for its own content: not a single hack or supplement, but the small set of durable systems (sleep, strength, blood work, attention) that compound over years.
Missing a term? This page gets updated as new posts introduce new vocabulary — check back, or follow the link from wherever you found the term.
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