{
  "schemaVersion": "1.0.0",
  "exerciseSlug": "crunch",
  "assetId": "crunch-preview-shaos-v1",
  "role": "preview",
  "status": "approved",
  "version": "v1.0.0",
  "reviewedAt": "2026-09-03",
  "source": {
    "canonicalArtwork": "/assets/exercises/crunch/anatomy.webp",
    "sha256": "426efc058d1e609fe03e9f2f17d9fb3ca3c423442c2b205cffcde5e8819bf0e3"
  },
  "production": {
    "method": "Identity-preserving key poses registered to a fixed pelvis, feet, and canvas and arranged into a seamless standard-tempo crunch loop.",
    "highlightCue": "Illustrative ShaOS activation cue; not an EMG measurement.",
    "highlightLegend": {
      "scheme": "primary-secondary",
      "primary": { "label": "Primary muscles", "color": "#D97706", "muscles": ["Abs"] },
      "secondary": { "label": "Secondary muscles", "color": "#8F969B", "muscles": [] }
    },
    "principle": "Keep the abs visible at rest, build through trunk flexion, peak at the top squeeze, and ease during the controlled return."
  },
  "playback": { "width": 720, "height": 720, "durationSeconds": 6, "frameRate": 20, "muted": true, "loop": true },
  "files": {
    "preview": { "path": "preview.mp4", "mimeType": "video/mp4", "bytes": 455721, "sha256": "4f237c2003d121b2894fdf5c2d74246db0f950ced02bc7bef57d6994b31601bf" },
    "poster": { "path": "poster.webp", "mimeType": "image/webp", "bytes": 19728, "sha256": "d9b47aa5e87a232e46d4f8dd5f9a9ad762bcae00a198780bcedd56836112aac8" }
  }
}