About KnowYourPrime

Your watch tells you your HRV was 38 last night. Your ring gives you a recovery score of 64. Your phone says your VO2 max is "above average for your age." None of them tell you what any of that actually means, whether 38 is worth a second thought, or what would move it if you wanted it to move.

That gap is why we built this. The devices are good at measuring and not good at explaining. They hand you a number and a green-yellow-red and leave you to guess at the rest.

KnowYourPrime is the part that does the explaining. We read the research on the numbers your wearable gives you, gather it into one place, and lay out what is actually known: what is normal for someone your age, what has been shown to move each number, and where the science still doesn't have a clean answer. You read your own numbers and draw your own conclusions. We don't tell you what to do with them.

What we are

Independent. KnowYourPrime is not owned by a wearable company and does not sell a device, a supplement, or a program, so no product's sales depend on your number looking a certain way.

Sourced. Every claim about what a number means, or what moves it, links to the study it came from. Where the evidence is strong, we say so plainly. Where it is mixed, we say that. How sources are weighed is on the methodology page.

Interpretation, not instruction. "People in the trial who drank within three hours of bed had lower overnight HRV" is the kind of thing you'll read here. "Stop drinking before bed" is not.

What we cover

Thirteen measurements, each with its own Research Desk: heart rate variability, resting heart rate, sleep, VO2 max, wearable ECG, continuous glucose monitoring, recovery, activity, blood oxygen, respiratory rate, stress, temperature, and blood pressure. We also cover the devices themselves: what each one calls a metric and how it measures it, from the manufacturer's own current documentation. The research reaches into what moves those numbers, including sleep, stress, alcohol, illness, training, age, and sex.

What it costs, and how to reach us

Free to read, with no account, no paid tier, no ads and no affiliate links. The site is self-funded: no sponsors, and no payments or free devices from any manufacturer. Questions go to hello@knowyourprime.com and errors to corrections@knowyourprime.com; the contact page has both. The Evidence Registry findings are also published as data at /evidence.json, licensed CC BY 4.0: reuse them with credit and a link back.

What we are not

This site is not medical advice, a diagnosis, or a substitute for your own doctor.