264 KB0 KB200520252017Sepe, AnaSerša, IgorUšaj, Antonštevilka:1/2letnik:65str. 170-173ISSN:0353-7455COBISSID:5138865URN:URN:NBN:SI:doc-DQFXI6IBslFakulteta za športŠport (Ljubljana)dinamično krčenjedynamic contractionforearm musclesmišice podlahtiMRSNIRSNMRsportstrength endurancešportvzdržljivost v močiRazlike v trajanju dinamičnega krčenja mišic z uporabo dveh intervalov krčenja in sproščanja|Possible differences between two dynamic contractions to fatigue: the one sec and 15 kp contraction followed by one sec relaxation intervals (1:1) and two sec 15 kp contraction followed by two sec relaxation (2:2) were studied. Two groups of 6 and 11 subjects performed 1:1 and 2:2 exercises of squeezing of rubber ring, to fatigue. Muscle metabolism was estimated by MRS (magnetic resonance spectroscopy) and NIRS (near infrared spectroscopy). Creatin phosphate (CrP) and parameters of muscle oxygenation were measured. Fluctuation characteristics of oxygenation parameters were calculated. Results shows that used exercises 1:1 (337 +- 249 s) and 2:2 (578 +- 271 s) were not different in their duration in spite of a clear tendency that 2:2 became longer. In according to these results also metabolic parameters weren't different. However, fluctuations of oxygenated hemoglobin (O2Hb) at 1:1 and at 2:2 has shown a clear tendency for larger fluctuations of muscle oxygenation in 2:2. It may be concluded that muscle tried to enhance its oxygen consumption during larger (2 s) relaxation. The possible effect of this phenomenon may be tendency for enhancement of exercise durationCilj naloge je bil ugotoviti morebitne razlike med dvema različnima krčenjema: enim z izmenjujočima se enosekundnim intervalom (1 : 1) ter drugega, z dvosekundnim intervalom krčenja in sprostitve (2 : 2), če mišice podlakti obremenimo z 15 kp. V ta namen sta dve skupini: 6 in 11 preiskovancev opravili stiskanje gumijastega obroča v zapestju do utrujenosti, in sicer s krčenjema 1 : 1 in 2 : 2. Mišična presnova je bila merjena z MRS (magnetna resonančna spektroskopija) in NIRS (bližnja infrardeča spektroskopija). Merjene so bile vsebnosti kreatin fosfata (CrP) in kazalci oksigenacije v mišici. Izračunane so fluktuacije oksigenacijskih kazalcev. Rezultati ne kažejo razlik v trajanju obeh krčenj, čeprav kaže krčenje 1 : 1 izrazito tendenco krajšega trajanja (337 +- 249 s) v primerjavi z 2 : 2 (578 +- 271 s). Tudi kazalci presnove ne razlikujejo obeh vrst krčenj. Toda fluktuacije oksigeniranega hemoglobina (O2Hb), pri 1 : 1 in pri 2 : 2 kažejo jasno tendenco po večjih vrednostih pri krčenjih 2 : 2. Mogoče je zaključiti, da sta si krčenji 1 : 1 in 2 : 2 dokaj podobni. Toda jasna tendenca po bolj izraženih fluktuacijah oksigeniranega hemoglobina pri krčenjih 2 : 2 nakazuje, da mišica poskuša privzeti več kisika, ki ji ga omogoča daljši interval sprostitve. Pri tem kaže tendenco po podaljšanju trajanja krčenja do utrujenostiTEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaUniverza v Ljubljani, Fakulteta za šport