1. Greater loss in muscle mass and function but smaller metabolic alterations in older compared to younger men following two weeks of bed rest and recoveryRado Pišot, Uroš Marušič, Gianni Biolo, Sara Mazzucco, Stefano Lazzer, Bruno Grassi, Carlo Reggiani, Luana Toniolo, Pietro Enrico Di Prampero, Angelina Passaro, Marco Vincenzo Narici, Shahid Mohammed, Joern Rittweger, Mladen Gasparini, Mojca Gabrijelčič Blenkuš, Boštjan Šimunič, 2016, original scientific article Keywords: ageing, prolonged physical inactivity, functional decline, reconditioning Published in RUP: 08.08.2016; Views: 3546; Downloads: 192 Link to full text |
2. Single muscle fibre contractile properties differ between body-builders, power athletes and control subjectsJ. P. Meijer, R. T. Jaspers, Joern Rittweger, Olivier Seynnes, S. Kamandulis, M. Brazaitis, A. Skurvydas, Rado Pišot, Boštjan Šimunič, Marco Vincenzo Narici, Hans Degens, 2015, original scientific article Keywords: skeletal muscles, muscle fibers, contractile properties, body-builders, power athletes Published in RUP: 08.08.2016; Views: 4322; Downloads: 196 Link to full text |
3. Odziv sestave telesa, mišične togosti in ravnotežja po 35-dnevni odsotnosti gibanja pri mladih in zdravih preiskovancihBoštjan Šimunič, Joern Rittweger, Gregor Cankar, Mihaela Jurdana, Tadeja Volmut, Tina Šetina, Igor B. Mekjavić, Rado Pišot, 2008, original scientific article Abstract: Uvod: Problemi sedečega načina sodobnega življenja se kažejo v fizioloških odzivih, tako pri starejših kot tudi pri mlajših ljudeh. Cilj raziskave je bilugotoviti odziv morfoloških in skeletno-mišičnih značilnosti ter izgubo funkcionalnih sposobnosti ohranjanja ravnotežja po 35-dnevni popolni gibalni nedejavnosti in zagotovljeni uravnoteženi prehrani glede na njeno sestavo in preiskovančevo telesno težo. Metode: Deset moških preiskovancev (starih 24,32,6 let) je v bolnišničnem okolju preležalo 35 dni v vodoravnem položaju. Fiziološke odzive telesa smo vrednotili z merjenji telesne, maščobne in mišične mase, mineralne vsebnosti sprednje golenske kosti, togosti trebuha dveh funkcionalno različnih glav antigravitacijske mišice in sposobnost ohranjanja ravnotežja. Rezultati: Preiskovanci so v povprečju značilno izgubili 0,97 % (P=0,001) telesne teže, 4,1 % (P=0,009) mišične mase in 1,7 % (P=0,000) mineralne gostote tibialne kosti ter pridobili 1,4 % (P<0,000) maščobne mase. Mišična togost se je značilno zmanjšala od 8. dne ležanja (P=0,006) dalje pri distalni in že od 1. dneva (P=0,007) dalje pri proksimalniglavi notranje stegenske mišice ter se 14. dan po zaključku BR vrnila v izhodiščno stanje le pri distalni glavi. Po zaključku BR in dan kasneje smo ugotovili značilno izgubo ohranjanja ravnotežja za 9,5 % (P=0,006), in 17,4 % (P=0,000), medtem ko 14. dan po zaključku ležanja ni biloveč značilnih razlik. Zaključek: Povzamemo lahko, da z uravnoteženo prehrano lahko omejimo izgubo telesne teže in pridobivanje maščobne mase, vendar ne moremo zmanjšati izgube mišične mase ter mineralne vsebnosti tibialne kosti. Ugotovili smo, da se mišična togost zmanjšuje v dveh časovno zakasnjenih procesih. Sposobnost ohranjanja ravnotežja je zmanjšana v vsaj prvih 24 urah po zaključku ležanja. Keywords: popolna gibalna neaktivnost, okoljska fiziologija, tenziomiografija, ravnotežje, morfologija, kostna mineralna vsebnost, mišična togost Published in RUP: 15.10.2013; Views: 4535; Downloads: 88 Link to full text |
4. Noninvasive estimation of myosin heavy chain composition in human skeletal muscleBoštjan Šimunič, Hans Degens, Joern Rittweger, Marco Vincenzo Narici, Igor B. Mekjavić, Rado Pišot, 2011, original scientific article Keywords: Tensiomyography, fiber type, myosin heavy chain, mechanomyography Published in RUP: 15.10.2013; Views: 4118; Downloads: 192 Link to full text |
5. Costamere remodeling with muscle loading and unloading in healthy young menRuowei Li, Marco Vincenzo Narici, Robert M. Erskine, Olivier Seynnes, Joern Rittweger, Rado Pišot, Boštjan Šimunič, M. Flück, 2013, original scientific article Keywords: costamere, atrophy, focal adhesion kinase, hypertrophy, physical inactivity, bed rest, skeletal muscle, myofibril, vinculin Published in RUP: 15.10.2013; Views: 3866; Downloads: 154 Link to full text |
6. Skeletal muscle oxidative function in vivo and ex vivo in athletes with marked hypertrophy from resistance trainingDesy Salvadego, R. Domenis, Stefano Lazzer, Simone Porcelli, Joern Rittweger, Giovanna Rizzo, I. Mavelli, Boštjan Šimunič, Rado Pišot, Bruno Grassi, 2013, original scientific article Abstract: 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 Keywords: skeletal muscle, hypertrophy, mitochondrial respiration, oxidative metabolism, exercise Published in RUP: 15.10.2013; Views: 4107; Downloads: 151 Link to full text |