What is being measured, trended over time

A rolling trend, not a single number

A single weigh-in is noise: water, sodium, and digestion move the scale more than fat or muscle do day to day. MuscleBuddy logs each entry and trends it on a rolling 7-day average, so the line reflects the underlying direction instead of the daily wobble.

Weight comes in by manual entry or smart-scale sync, and every row is tagged with where it came from, manual, synced, estimated, or imported, so you always know what kind of reading you're looking at. That trend line is also what Nutrition reads: your calorie and macro targets move off it, not off a number you set once and forgot.

Body fat: measured, synced, or estimated

Body fat percentage can come from a smart scale, from a DEXA or InBody-style scan (weight, body fat, skeletal muscle mass, fat-free body weight, visceral fat level, body water percentage, bone mass, metabolic age, BMR, and bone density T- and Z-scores where your scan provides them), or from one of two estimators built into the app: the Navy method (waist, neck, and hip circumference) and Jackson-Pollock skinfolds. Every estimator result is labelled as an estimate, because that's what it is.

Whatever the source, each metric gets its own trend line on the body composition page, so you can watch a single value move over months instead of comparing two snapshots by memory.

Tape measurements and bilateral symmetry

Waist, hips, chest, neck, and paired left/right arms, quads, and calves all log as their own entries. Left/right pairs feed a bilateral symmetry score: how close your two sides track each other, and which side is currently larger, with sub-half-centimeter gaps treated as even rather than flagged as a difference tape measurement can't reliably catch.

Symmetry sits next to your training data on the same page, so an imbalance is something to notice and address in your programming, not a number floating on its own.

A visual timeline, mapped to your numbers

Progress photos log against a pose (front, back, side, and the rest of the catalogue), a date, and optional notes, and each new photo can overlay the previous one in the same pose at an adjustable opacity, so a change between two shots is something you can see directly rather than infer. Every photo lines up on the same timeline as your weight and body fat entries, so the visual record and the numeric one are always read together.

How it reads the rest of the system

Body composition isn't an island. Your weigh-in trend drives Nutrition's calorie and macro targets directly. Training reads your logged sessions and volume separately, so a stall in one doesn't quietly get blamed on the other. Health context, recovery, sleep, and check-ins sits alongside the same trend so a plateau has somewhere to look for an explanation, and Upkeep's medication and condition tracking can explain a weight or measurement shift that training and nutrition data alone wouldn't. And on your avatar, Fuel, Nourishment, and part of Fullness are computed from the same underlying data, so what you log here is never siloed to one screen.