Human study · Exercise · 9 Mar 2026
Eight weeks of HIIT expanded mitochondrial cristae in men aged 40–65, including those with type 2 diabetes
Source: EurekAlert
What the research found
Study (training trial). Martin Eisemann de Almeida and colleagues at the University of Southern Denmark and Steno Diabetes Center Odense analysed muscle biopsies from 44 men aged 40–65 (15 with overweight and type 2 diabetes, 15 with overweight without diabetes, 18 of normal weight) after eight weeks of HIIT (rowing or cycling intervals, three sessions/week). Electron microscopy of about 11,000 mitochondria showed more mitochondria and about 7% expansion of cristae (the inner membrane where energy is produced) across groups, including men with type 2 diabetes. Small, men-only sample; maintenance after stopping training was not tested. This is not a diabetes treatment protocol. Educational exercise notes, not medical advice.
Evidence level: Human study. A study in people, but an association isn't proof of cause.
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