Capillary differences with age and fiber type are attenuated by accounting for fiber shape

This dataset contains quantitative measurements of skeletal muscle fiber morphology and capillarization in young and older women. Muscle biopsies were obtained from both a rested leg and a leg that had performed a single bout of heavy resistance exercise five days prior to sampling. Variables include muscle fiber cross-sectional area, perimeter, and Shape Factor Index (SFI), as well as multiple indices of capillarization, including capillary density, capillary-to-fiber ratio, individual capillary-to-fiber ratio, and morphology-adjusted capillarization metrics. The dataset enables analysis of age-, fiber type-, and condition-related differences in muscle fiber geometry and capillary supply.
, , # Capillary differences with age and fiber type are attenuated by accounting for fiber shape

Dataset DOI: [10.5061/dryad.9p8cz8wwr](10.5061/dryad.9p8cz8wwr)

## Description of the data and file structure

This dataset derives from a study of skeletal muscle capillarization in young and older women. Muscle biopsies were collected from both legs of each participant. One leg performed a single bout of heavy resistance exercise five days prior to sampling (Exercised leg), while the contralateral leg served as the rested control (Rested leg). Each sample is identified by a unique alphanumeric sample ID corresponding to participant and leg.

Muscle biopsies were embedded, frozen, cryosectioned, and immunohistochemically stained for type I myosin heavy chain (fiber type identification), laminin (fiber borders), and CD31 (capillaries). From these sections, muscle fiber cross-sectional area, perimeter, and the derived Shape Factor Index (SFI) were quantified. Capillarization was evaluated using..., All participants provided explicit written consent for their data to be made publicly available in de-identified form. Prior to sharing, all direct identifiers were removed. The resulting dataset contains no information that could be used to re-identify individuals.