Explain the body in 3D: how to make a health explainer people remember

Twenty seconds on “where does the fat go?”

The video opens on a see-through 3D body, turning slowly. A warm yellow glow spreads over the belly, labelled “fat”, and the voice asks: “Lose ten kilos of fat. Where does it all go?”

Yellow drops leave the belly and travel through the blood, up to the heart. The camera dives to the lungs; they light up, and the drops stream up the windpipe and out of the mouth. A number counts up to 8.4, “kg breathed out”. The camera turns round behind the body, where light-blue drops run from the kidneys down to the bladder, which fills: the other 1.6 kilos leave as water. Back to the front, the lungs glowing with each breath out. “Fat doesn’t just vanish. You breathe most of it out.”

The numbers come from a 2014 paper in the BMJ by Ruben Meerman and Andrew Brown, who followed the atoms of fat through the body. Burned for energy, fat ends up as carbon dioxide and water: of every ten kilos, about 8.4 are breathed out and 1.6 leave as water. A simple question, a surprising answer, a path through the body you can follow. That is the shape of a good 3D anatomy video.

Why a 3D body explains more than a flat diagram

A textbook diagram is a map with the depth taken out. It is good for naming parts and weak at what health and fitness questions actually ask: where, how big, what moves, what happens inside.

• Location. The kidneys sit at the back of the belly, not the front. On a flat front view people guess; when the camera turns round behind the body, nobody has to.
• Scale. The lungs fill most of the chest, and the liver is the largest organ inside the body. Seeing parts at their real size, side by side, is half the explanation.
• Movement. A joint bends, a body squats, blood travels its channels. Fitness is about motion, and a still picture can only point at it.
• Inside and outside at once. A glass-like skin shows the organs and the person together, so “your lungs” stays attached to “you”.

Research on learning from video points the same way. Richard E. Mayer’s principles of multimedia learning include signaling (highlight what matters) and temporal contiguity (show a thing at the moment the words name it). An organ that lights up on its word does both.

How to write a script for a 3D anatomy video

The fat video’s script is printed under it exactly as it was pasted. Four habits in it are worth copying.

1. One organ or system per beat. The belly, then the blood, then the lungs, then the kidneys. Each short paragraph gets one place in the body, so the viewer always knows where to look.
2. A [note] before each line, saying what the camera and the body do. Notes in brackets direct the scenes and are never read aloud: “[The camera dives to the lungs. They light up, and drops stream up the windpipe and out of the mouth.]” Write them like stage directions: where the camera goes, what lights up, what moves. Turn off Rewrite into a narration, so the voice reads your lines as written and your notes stay notes.
3. Numbers that count up. “8.4 kg breathed out” lands harder as a number climbing on screen than as a word in a sentence. Ask for it in the note, and say it in the line.
4. Lines short enough to watch: one idea, ten to fifteen words. The voice says about three words a second, so a note’s action has to fit inside its line. In an earlier example of ours, a note asked for three slow squats over a line that took about seven seconds to say. The body did all three, at a speed nobody squats. Two would have fit.

3D anatomy video ideas for coaches, nutritionists, physios and teachers

Good subjects share a shape: a simple question, an answer most people have never pictured, and a path through the body the camera can follow.

• Coaches: what happens in a squat. The body squats; the thighs and glutes light up as the voice names them; the camera turns to the side to show the hips going back and down.
• Coaches and runners: why you breathe harder when you train. Working muscles burn more fuel, so they need more oxygen and make more carbon dioxide; the heart beats faster and the lungs work harder to keep up.
• Nutritionists: where the water you drink goes. Into the blood through the intestines, filtered by the kidneys, stored in the bladder. Drops travelling the channels make it obvious.
• Nutritionists: the journey of a meal. Down the oesophagus, into the stomach, through the small intestine, where most nutrients are absorbed, and on to the large intestine.
• Physios: the spine, vertebra by vertebra, the discs that cushion them, and the pelvis it stands on.
• Biology teachers: the two loops of the blood. From the heart to the lungs and back, then out to the whole body and back again, arteries in red and veins in blue.

Keep it to how the body works. A 3D body is a clear way to show what happens inside; what a particular person should do about their own body is a conversation for their doctor.

Can you put it on your own training clips?

Yes, the other way round. Upload a clip of yourself training under My video, pick 3D Body and choose AI narrates: at the key moments the video freezes and the muscles at work are painted on you, in the Anatomy or Sci-fi look. The director can also cut away to the 3D body alone for what can’t be seen on you, like the inside of a joint.

We walk through that whole process, from filming the set to the finished lesson, in from gym clip to coaching lesson.

How to make your first 3D anatomy video

1. Pick one question and answer it in five or six short lines.
2. Put a [note] before each line: what the camera does, what lights up, what moves.
3. In Create, paste the text (or import a document), turn off Rewrite into a narration and choose the 3D Body style. Or upload your own voice recording, with directions for the scenes in the Script & notes box.
4. Pick a format (16:9 for a course, 9:16 for Reels, Shorts and TikTok) and, for a text, a voice. Click Generate: the price is shown first.
5. In the studio, change any scene or ask the video assistant in plain words. Export a 1080p MP4.

You start with 300 free credits on sign-up, no card: enough for a short video like the one above. See what else the 3D Body style can show, and how fitness coaches use it in their programs.