What an InBody 570 Scan Actually Measures (and What It Doesn't)

Most people walk out of an InBody scan staring at one number: body fat percentage. The print-out has a dozen others, and several of them are quietly more useful for a long-term training decision. Here's how we read it on the floor.

What it actually measures

The InBody 570 is a multi-frequency bioelectrical impedance analyzer. A small electrical current passes through the body via hand and foot electrodes, and the device infers tissue composition from how the current behaves at different frequencies. Lean tissue (which holds water) conducts well; fat tissue does not. From those measurements the device estimates lean mass, body fat mass, body water, and visceral fat.

The four numbers we look at first, every time, in this order:

1. Skeletal muscle mass — the lean tissue that does the work of moving and protecting you.
2. Segmental lean balance — how lean mass is distributed across the five segments (left arm, right arm, trunk, left leg, right leg). Asymmetries point at history.
3. Visceral fat area — the fat around the organs, which carries the metabolic risk.
4. Phase angle — a cellular-health proxy that drifts upward as training quality improves.

Body fat percentage is the headline number, but it's a derivative of the others. We use it to track direction, not to grade a session.

Why we re-scan every four weeks

Body composition does not change in two-week increments in any meaningful way for most adults. Four weeks is roughly the window in which a training stimulus produces a measurable shift in lean mass and the body has had time to respond to a programming change. Scan more often than that and you're mostly measuring hydration noise. Scan less often and the program has been adjusting on guesses for too long.

What it can't tell you

Three things, plainly:

• It cannot tell you about bone density. A DEXA scan is still the gold standard for that.
• It cannot tell you whether you're recovering well. Heart-rate variability, sleep quality, and how you feel mid-session are better recovery indicators.
• It cannot tell you whether your program is on the right track in any given week. A single scan is a data point, not a verdict. Trends across several scans matter; one scan does not.

How to read your own print-out

Look at three trends across your last three scans. First, is skeletal muscle mass holding or rising? Second, is visceral fat area falling or flat? Third, are the segmental bars roughly even? If those three are moving the right direction, the program is working — even if the body fat percentage hasn't moved in a single dramatic step. The body composes itself slowly. The scan just makes the change visible.

Want to see your own print-out? You can book a single InBody 570 scan on its own at the studio, or have it built into your training as a four-week rhythm.