Who built it
Longevity Coach IQ is built by Daniel Salcumbe, in the UK. You can find him on LinkedIn.
He served as a Royal Engineer in the British Army, qualified as a personal trainer afterwards, and has spent fifteen years in the fitness industry since. He founded My Personal Trainer Website and the Institute of Personal Trainers, both of which serve personal trainers rather than the general public.
He is not a doctor, and Longevity Coach IQ does not pretend otherwise. That fact shapes how the whole thing is built: rather than asking you to trust professional authority, every score traces back to a published benchmark you can go and check, the methodology is written out in full, the source of every threshold is published, and the encyclopedia states where evidence is weak as readily as where it is strong.
If a claim here rests on a single mouse study, the entry says so. If a marker has no good consumer test, the entry says that too rather than inventing a proxy to fill the gap.
How it started
It began as somewhere to put his own numbers. Fifteen years in the industry produces a large pile of collected research and no good way to apply it to yourself, and the tracking apps that existed returned a dashboard rather than an order of priority.
The encyclopedia came out of the same pile: a decade of papers and guidelines, written up so the reasoning behind each threshold is visible rather than buried in the scoring. Enough people he talked to about longevity said it should be an app that eventually it became one.
Why it exists
Most health tracking produces a dashboard. You end up with twenty numbers, no idea which of them matters, and no plan. Meanwhile the longevity industry sells confidence far ahead of its evidence, in a category where an ordinary person has almost no way to tell a well-supported claim from a well-marketed one.
Longevity Coach IQ, the longevity app this site belongs to, was built for the second problem more than the first. It scores you against published percentile data for your age and sex, ranks what to work on by how much it actually moves, and is explicit about the difference between a marker with decades of mortality data behind it and one with a promising mechanism and no outcomes.
How the encyclopedia is written
Six rules govern every entry: state the number, grade the evidence, name the limits, answer against interest, separate clinical ranges from optimal ones, and update when the evidence does. Entries are written from a personal research library rather than assembled at the point of writing, there is currently no clinical reviewer, and AI tools assisted in drafting with every claim verified by a human.
All of that is set out in full, along with a public log of corrections, on the editorial policy page.
What this is not
This is not medical advice, and it is not a substitute for a doctor. It cannot diagnose anything. If a number here concerns you, the correct next step is a clinician who can examine you, not a webpage.
It is also not a research institution. The encyclopedia is a careful synthesis of published work, written to be honest about its own confidence. Where an entry cites a specific study or body, that source is named on the page so you can go to the original rather than taking this site's word for it.
Corrections
If something here is wrong, we would rather know. Email support@longevitycoachiq.com with the entry and the correction, and it will be checked against the source and fixed if it does not hold up.
Related reading: the scoring methodology explains how markers become a score, and the encyclopedia covers the individual markers, habits and interventions in full.