{
  "id": 10656688,
  "title": "The hidden switch behind one of the biggest paradoxes in aging muscle",
  "url": "https://urgent.news/2026/09/29/the-hidden-switch-behind-one-of-the-biggest-paradoxes-in-aging-muscle",
  "topic": "science",
  "section": "Science",
  "published": "2026-09-29T09:00:02.000Z",
  "source": {
    "name": "Medical Xpress",
    "slug": "medical-xpress",
    "url": "https://medicalxpress.com/news/2026-09-hidden-biggest-paradoxes-aging-muscle.html"
  },
  "original_language": "en",
  "account": null,
  "summary": "Our muscles are built from bundles of fibers. Some are fast-twitch, tuned for quick, powerful bursts of effort but quick to tire. Others are slow-twitch, built for endurance and packed with more mitochondria, the structures commonly called the \"powerhouses of the cell.\"",
  "key_points": [],
  "editors_take": null,
  "illustration": null,
  "coverage": {
    "outlets": 1,
    "also_reported_by": []
  },
  "ai_generated": true,
  "disclaimer": "Summaries, key points and the editor’s take are written by software from other outlets’ reporting and may contain errors — always check the linked original."
}