Body scanner · 体組成分析

Ten measurements that actually tell you something.

Body composition is not vanity — for a karateka it is direct competitive intelligence. Weight class compliance, power-to-weight ratio, reach advantage, and explosive output all show up in measurement. Below: the ten metrics worth tracking, a private log that lives only on this device, where to get them, and how to use them without falling into the trap of measuring for measurement's sake.

10 METRICS · LIVE LOG · COMPOSITION CALCULATOR · 6 EQUIPMENT TYPES · 5 PRIVACY GUARANTEES · 7-STEP PROTOCOL
Metric explorer

Pick a metric · see what it tells you.

Body weight
Unit · kg
WHY MEASURE
Tournament weight class compliance. Track changes ±1kg before weigh-in week.
FREQUENCY
Daily on training days
HEALTHY RANGE
Within 0.5kg of target weight class
WARN IF
More than 2kg variance week-to-week
METHOD
Calibrated platform scale, post-toilet, pre-breakfast, no gi
Your measurement log

Track body weight over time.

Add a reading for the metric selected above. Everything here is stored only in this browser — nothing is uploaded. Decisions belong on the rolling median, never a single reading.

VALUE (kg)
DATE
CONTEXT (OPTIONAL)
Composition calculator

Turn three numbers into lean and fat mass.

Enter your weight, height, and a body-fat reading. The calculator splits your mass into lean tissue (the part that produces force) and fat mass live as you type. BMI is shown for completeness — it is a blunt instrument for athletes and should never be read alone.

WEIGHT (KG)
HEIGHT (CM)
BODY FAT (%)
—
BMI
—
Lean mass
—
Fat mass
Six measurement stations

Where to actually measure.

Select the stations you plan to use this season. The estimator totals a per-session cost band live below. Single-purchase tools (scale, dynamometer) are treated as negligible per-use.

STATION
DEXA scan
Body fat % and lean mass with clinical accuracy. The benchmark.
WHERE Sports medicine clinics; some elite training centresCOST CHF 90–180 per scanCADENCE Quarterly or seasonal
STATION
Multi-frequency BIA
Estimated body composition. Good for trend tracking when DEXA unavailable.
WHERE Many dojos have portable units; some gymsCOST CHF 15–40 per scanCADENCE Monthly
STATION
Velocity gate
Hand and leg speed measurement at point of impact.
WHERE High-performance centres and sports labsCOST CHF 30–60 per sessionCADENCE Quarterly
STATION
Force plate
Ground reaction force during kicks and stance transitions.
WHERE Research labs and elite sports institutesCOST CHF 80–150 per sessionCADENCE Annually for elites
STATION
Calibrated dynamometer
Grip strength baseline and tracking.
WHERE Most dojos can purchase; CHF 60–120 single unitCOST Per-use negligibleCADENCE Quarterly
STATION
Standard scale + height rod
Weight and height. Foundation data.
WHERE Any dojoCOST CHF 40–90 single purchaseCADENCE Daily/weekly
0 STATIONS SELECTED
CHF 0per cycle
Measurement protocol

How to read your own data.

01
Standardise the time of day
Always weigh at the same time. Morning, post-toilet, pre-breakfast is the platform recommendation.
02
Standardise hydration state
Drink the same amount of water in the hours before. A 1.5kg swing between morning and evening is normal — measure consistently.
03
Standardise clothing
Light shorts and t-shirt only, or measurement clothes. No gi. No belt. Same setup every time.
04
Use the same device
Different scales read differently. Pick one, stick with it. Note device serial in your log if precision matters.
05
Log the context
Note: training load week, sleep quality the night before, any illness, menstrual cycle phase for female athletes. Numbers without context mislead.
06
Avoid measurement around competition
In the 7 days before a tournament weigh-in, suspend other body composition checks. Daily weight only. Less measurement, less noise.
07
Trends, not points
A single reading is noise. A 4-reading trend is data. Make decisions on the rolling 4-week median, not on yesterday's number.
Privacy guarantees

This data is yours.

Who can see your data
You, your sensei, your assigned coach if any. Your federation: only the metrics you mark as competition-relevant (weight, reach, height). Nobody else.
Flagging concerning trends
If body-fat or lean mass shifts trigger automatic concern (e.g. low body-fat sustained), the platform notifies your sensei privately — not your federation, not your peers.
Junior athletes
Body composition tracking for athletes under 16 is opt-in by parent only. Body-fat % is not displayed publicly under any circumstance. Weight tracking is permitted but flagged for welfare review if changes exceed normal growth bands.
Your right to export
Every measurement is yours. Export anytime as CSV — no platform retention required. Delete entries individually or all at once.
No third-party sharing
Body-scanner data is never sold, shared with insurance partners, or licensed to research projects without your individual written consent. Anonymous aggregate research is opt-in.
Caution
Measurement is a tool, not the goal.
Athletes who become obsessed with body-fat percentages, who weigh themselves five times a day, who eliminate food groups based on a single bad reading — they retire injured, ill, or burnt out. Numbers serve training, not the other way around. If you find a measurement pattern making you anxious, talk to your sensei and consider a measurement holiday. The dojo is the place; the platform is the record.
Related
Body weight log →Health Index →Wellness log →Training log