Desy Salvadego (Avtor), R. Domenis (Avtor), Stefano Lazzer (Avtor), Simone Porcelli (Avtor), Joern Rittweger (Avtor), Giovanna Rizzo (Avtor), I. Mavelli (Avtor), Boštjan Šimunič (Avtor), Rado Pišot (Avtor), Bruno Grassi (Avtor)

Povzetek

Oxidative function during exercise was evaluated in 11 young athletes with marked skeletal muscle hypertrophy induced by long-term resistance training (RTA, body mass 102.67.3 kg, meanSD) and 11 controls (CTRL, body mass 77.86.0). Pulmonary O2 uptake (V'O2) and vastus lateralis muscle fractional O2 extraction (by near-infrared spectroscopy) were determined during an incremental cycle ergometer (CE) and one-leg knee-extension (KE) exercise. Mitochondrial respiration was evaluated ex vivo by high-resolution respirometry in permeabilized vastus lateralis fibers obtained by biopsy. Quadriceps femoris muscle cross sectional area, volume (determined by magnetic resonance imaging) and strength were greater in RTA vs. CTRL (by ~40%, ~33% and ~20%, respectively). V'O2peak during CE was higher in RTA vs. CTRL (4.050.64 L min-1 vs. 3.560.30); no difference between groups was observed during KE. The O2 cost of CE exercise was not different between groups. When divided per muscle mass (for CE) or quadriceps muscle mass (for KE) V'O2peak was lower (by 15-20%) in RTA vs. CTRL. Vastus lateralis fractional O2 extraction was lower in RTA vs. CTRL at all work rates, both during CE and KE. RTA had higher ADP-stimulated mitochondrial respiration (56.723.7 pmolO2s-1mg-1 ww) vs. CTRL (35.710.2), and a tighter coupling of oxidative phosphorylation. In RTA the greater muscle mass and maximal force, and the enhanced mitochondrial respiration seem to compensate for the hypertrophy-induced impaired peripheral O2 diffusion. The net results are an enhanced whole body oxidative function at peak exercise, and unchanged efficiency and O2 cost at submaximal exercise, despite a much greater body mass

Ključne besede

skeletal muscle;hypertrophy;mitochondrial respiration;oxidative metabolism;exercise;

Podatki

Jezik: Angleški jezik
Leto izida:
Tipologija: 1.01 - Izvirni znanstveni članek
Organizacija: UP - Univerza na Primorskem
UDK: 612:796.01
COBISS: 2371027 Povezava se bo odprla v novem oknu
ISSN: 8750-7587
Št. ogledov: 3694
Št. prenosov: 151
Ocena: 0 (0 glasov)
Metapodatki: JSON JSON-RDF JSON-LD TURTLE N-TRIPLES XML RDFA MICRODATA DC-XML DC-RDF RDF

Ostali podatki

Sekundarni jezik: Neznan jezik
Vrsta dela (COBISS): Delo ni kategorizirano
Strani: str. 1527-1535
Letnik: ǂVol. ǂ114
Zvezek: ǂno. ǂ11
Čas izdaje: 2013
DOI: 10.1152/japplphysiol.00883.2012
ID: 1493956