Capacity 03 · Preserve Functionality
Signal · BMD / T-score

The skeleton that holds you is built by decades of load.

Bone mineral density is the mineral-per-area in your skeleton. The T-score compares you to a healthy young adult. Unlike muscle, bone turns over slowly — every decade of consistent mechanical load matters, and the windows to build it are finite.


The ranges that matter

Four bands. One direction.

What matters most is the direction over time under the same conditions — is the number trending toward the Fit band, or drifting away from it? Your Radar scores every marker 0–100 on the same four-band continuum you see on your report: Fit (90+), Well (50–89), Short of well (26–49), Sick (25 and under). A score of 25 is the diagnosable line at any age. The values below are the age-40 reference — the bands shift with your age and sex, so use the calculator underneath for your own numbers.

Fit
T-score ≥ 0.3
Strong bone reserve, at or above the healthy young-adult reference. Low fracture risk into aging.
Well
T-score −1.2 – 0.3
Average density. Still inside “normal,” with less reserve than optimal. Load is the prescription.
Short of well
T-score −2.5 – −1.2
Osteoporosis is diagnosed at −2.5, and the Radar scores exactly 25 there. Osteopenia begins at −1.0, one band earlier. Fracture risk rises steeply through here.
Sick
T-score ≤ −2.5
Severe osteoporosis. Load still matters, but this belongs in a physician’s hands alongside the coaching.
UnitT-score (SD units) — not areal g/cm²
Test typeDXA scan (spine and hip)
Look atT-score at the hip and lumbar spine

What it reveals

Bone remembers the load.

Bone is a living tissue. It is constantly being broken down and rebuilt — but slowly. Peak bone mass is set in the late twenties; after that, maintenance requires consistent mechanical loading, adequate protein, and sufficient vitamin D, calcium, and sex hormones.

The T-score expresses your density in standard deviations away from a healthy young adult. Zero is the reference. −1.0 is low-normal. Below −2.5 is osteoporosis, where fracture risk rises sharply — often for the first time through a trivial fall.

Bone responds to load that is heavier than daily life. Walking preserves; running maintains; lifting heavy and jumping build. Unloaded cardio, while valuable for other capacities, is not sufficient to protect bone.

BMD belongs in Preserve Functionality because the skeleton carries everything else. A hip fracture in the later decades is one of the single worst life-course events, independent of the bone itself. Protect the scaffolding.

On the floor If your T-score is drifting, the signal is not to be afraid of load — it is that load needs to be the prescription. Bone does not build from caution. It builds from appropriate, progressively heavier mechanical stress.

Coaches only

The intervention levers live with coaches.

The education above is open to everyone. The specific levers — what to actually do to move this marker — are part of the coaching program. Enter your coach password to unlock, or get in touch about becoming a coach.

Interested in becoming a coach? Get in touch →

Go deeper
Get your Radar → Read the science All signals
Coaching and education only. Not medical diagnosis or treatment. Excerpts welcome with attribution to metabolicradar.com.