1. Fast and slow myofiber nuclei, satellite cells, and size distribution with lifelong endurance exercise in men and women
- Author
-
Cristhian F. Montenegro, Chad Skiles, Dillon J. Kuszmaul, Aaron Gouw, Kiril Minchev, Toby L. Chambers, Ulrika Raue, Todd A. Trappe, and Scott Trappe
- Subjects
aging ,cross‐sectional area ,fiber type specific ,masters athletes ,myonuclei ,satellite cells ,Physiology ,QP1-981 - Abstract
Abstract We previously observed lifelong endurance exercise (LLE) influenced quadriceps whole‐muscle and myofiber size in a fiber‐type and sex‐specific manner. The current follow‐up exploratory investigation examined myofiber size regulators and myofiber size distribution in vastus lateralis biopsies from these same LLE men (n = 21, 74 ± 1 years) and women (n = 7, 72 ± 2 years) as well as old, healthy nonexercisers (OH; men: n = 10, 75 ± 1 years; women: n = 10, 75 ± 1 years) and young exercisers (YE; men: n = 10, 25 ± 1 years; women: n = 10, 25 ± 1 years). LLE exercised ~5 days/week, ~7 h/week for the previous 52 ± 1 years. Slow (myosin heavy chain (MHC) I) and fast (MHC IIa) myofiber nuclei/fiber, myonuclear domain, satellite cells/fiber, and satellite cell density were not influenced (p > 0.05) by LLE in men and women. The aging groups had ~50%–60% higher proportion of large (>7000 μm2) and small (
- Published
- 2024
- Full Text
- View/download PDF