JennaRN said:The intervention that works is boring and well evidenced: resistance training two to three times a week at a genuine effort, protein at 1.4 to 2.0…
Muscle fiber type changes during GLP-1-mediated weight loss, relevant to lean mass: preliminary biopsy data suggests that weight loss shifts the skeletal muscle fiber type distribution:
- Decreased Type IIx (glycolytic, fast-twitch) fibers
- Increased Type I (oxidative, slow-twitch) fibers
- Improved mitochondrial density and function
- Enhanced insulin-stimulated glucose uptake per fiber
This "metabolic remodeling" of muscle may contribute to improved insulin sensitivity independent of total lean mass changes. The muscle you keep becomes metabolically better, even if there's less of it[1].
[1] Pirkmajer S, et al. Front Physiol. 2023;14:1123456.
Following on from newstart_MO — and this may be the naive question:
What fraction of loss being lean mass is actually normal, because the numbers quoted here range from 10% to 40% and cannot all be right?
HPLC_Greg said:Muscle fiber type changes during GLP-1-mediated weight loss, relevant to lean mass: preliminary biopsy data suggests that weight loss shifts the…
Coming at HPLC_Greg’s question from a different direction. Training does two things here and only one of them is on the scale. It protects lean mass — which is the reason to do it — and it contributes modestly to the deficit, which is the reason people start and then quit when the arithmetic disappoints them. In a deep deficit, resistance work is the priority and high-volume cardio competes with recovery.
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Shop Reference StandardsClosing the loop on my own question.
Second scan under matched conditions came back with the lean number nearly a kilogram higher than the first, so a chunk of what I panicked about was hydration. Strength numbers were up throughout.
DeniseRN_TPA said:Training does two things here and only one of them is on the scale.
Agreed on the ranges, with the condition that a single DEXA is not a measurement, it is one draw from a distribution. Hydration status moves the lean compartment by a kilogram or more between scans, so any comparison of scans done at different times of day or different hydration states is noise.