Metaxas, T, Mandroukas, A, Michailidis, Y, Koutlianos, N, Christoulas, K, and Ekblom, B. Correlation of fiber-type composition and sprint performance in youth soccer players. J Strength Cond Res 33(10): 2629-2634, 2019-The aim of this study was to examine the correlation between muscle fiber type and sprint performance in elite young soccer players of different age groups of the same team. Twenty-eight young players participated in this study (group U15, n = 8; group U13, n = 9; and group U11, n = 11). Anthropometric assessments, acceleration (10 m), and Bangsbo modified sprint test (30 m) were performed. Muscle biopsies were obtained from the vastus lateralis, and after that, fiber-type composition was determined by immunohistochemistry. No significant correlations were found between the sprint test and muscle fiber distribution for the groups U13 and U11 (p > 0.05). Also, no correlations were found between cross-sectional areas in the types of fibers with the sprint test in all groups (p > 0.05). A positive correlation was found between type I fibers and the performance in the acceleration test (10 m) (r = 0.77, p < 0.05) was found only in group U15 and a negative correlation between type IIA fibers and the performance in the acceleration test (10 m) (r = -0.89, p < 0.05). The correlations were observed only in group U15, which may indicate that the duration and the intensity of the soccer systematic training can affect the plasticity of the muscle fibers. Specific soccer training in youth is one of the factors that can affect fiber-type plasticity. The specific training programs and status of U15 are more intensive, and the exercises are oriented more to improve physical fitness.
- MeSH
- antropometrie MeSH
- běh fyziologie MeSH
- čtyřhlavý sval stehenní cytologie MeSH
- cvičení fyziologie MeSH
- dítě MeSH
- fotbal fyziologie MeSH
- lidé MeSH
- mladiství MeSH
- plasticita buňky MeSH
- sportovní výkon fyziologie MeSH
- svalová síla MeSH
- svalová vlákna typu I cytologie fyziologie MeSH
- svalová vlákna typu II cytologie fyziologie MeSH
- zátěžový test MeSH
- zrychlení MeSH
- Check Tag
- dítě MeSH
- lidé MeSH
- mladiství MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
Chronic hypoxia alters respiratory muscle force and fatigue, effects that could be attributed to hypoxia and/or increased activation due to hyperventilation. We hypothesized that chronic hypoxia is associated with phenotypic change in non-respiratory muscles and therefore we tested the hypothesis that chronic hypobaric hypoxia increases limb muscle force and fatigue. Adult male Wistar rats were exposed to normoxia or hypobaric hypoxia (PB=450 mm Hg) for 6 weeks. At the end of the treatment period, soleus (SOL) and extensor digitorum longus (EDL) muscles were removed under pentobarbitone anaesthesia and strips were mounted for isometric force determination in Krebs solution in standard water-jacketed organ baths at 25 °C. Isometric twitch and tetanic force, contractile kinetics, forcefrequency relationship and fatigue characteristics were determined in response to electrical field stimulation. Chronic hypoxia increased specific force in SOL and EDL compared to age-matched normoxic controls. Furthermore, chronic hypoxia decreased endurance in both limb muscles. We conclude that hypoxia elicits functional plasticity in limb muscles perhaps due to oxidative stress. Our results may have implications for respiratory disorders that are characterized by prolonged hypoxia such as chronic obstructive pulmonary disease (COPD).
- MeSH
- hypoxie patofyziologie MeSH
- končetiny fyziologie MeSH
- kosterní svaly fyziologie MeSH
- krysa rodu rattus MeSH
- svalová kontrakce fyziologie MeSH
- svalová vlákna typu I fyziologie MeSH
- svalová vlákna typu II fyziologie MeSH
- únava metabolismus MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- práce podpořená grantem MeSH
We developed a new method for the quantitative determination of myosin heavy chain (MyHC) isoforms taking advantage of immunochemical differences and based on the ELISA principle. In the present paper we compare analysis of MyHC isoforms using the SDS-PAGE and the ELISA methods in the same samples of adult female inbred Lewis strain euthyroid, hyperthyroid and hypothyroid rats. In all thyroid states, the same composition and corresponding changes of MyHC isoforms were determined using both methodological approaches in the slow soleus and the fast extensor digitorum longus muscles. Our results showed that ELISA can be used for a “semi-quantitative” or “comparative” measurement of MyHC isoforms in multiple muscle samples, but that it is neither more exact nor faster compared to SDS-PAGE.
- MeSH
- elektroforéza v polyakrylamidovém gelu MeSH
- ELISA MeSH
- inbrední kmeny potkanů MeSH
- krysa rodu rattus MeSH
- potkani inbrední LEW MeSH
- protein - isoformy analýza MeSH
- svalová vlákna typu I fyziologie chemie MeSH
- svalová vlákna typu II fyziologie chemie MeSH
- těžké řetězce myosinu analýza MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- práce podpořená grantem MeSH
- MeSH
- histamin fyziologie metabolismus MeSH
- hormony fyziologie metabolismus MeSH
- lidé MeSH
- myosiny fyziologie metabolismus MeSH
- nervový systém - fyziologické jevy MeSH
- příčně pruhované svaly MeSH
- svalová kontrakce fyziologie MeSH
- svalová síla fyziologie MeSH
- svalová vlákna typu I fyziologie MeSH
- svalová vlákna typu II fyziologie MeSH
- Check Tag
- lidé MeSH
