| Sažetak | Cilj: Brojni potencijacijski podražaji korišteni su u istraživanjima postaktivacijske potencijacije. Do sada za potencijacijski podražaj još nije korišteno elastični otpor u horizontalnom smjeru. Primarni je cilj kod nogometaša utvrditi ukupni akutni učinak sprinta sa elastičnim užetom na izvedbe sprinta, trčanja u slalomu i udarca po lopti te specifični akutni učinak s obzirom na dominantnosti horizontalnog mehaničkog profila. Sekundarni je cilj utvrditi razlike u izvedbama sprinta, slaloma i udarca prema dominantnosti u
horizontalnome mehaničkom profilu. Metode: U istraživanju je sudjelovalo 118 zdravih nogometaša iz sedam klubova Treće
hrvatske nogometne lige. Uključujući kriteriji za sudjelovanje u istraživanju bili su: (i) muški spol, stariji od 18 godina, (ii) minimalno 5 godina iskustva u nogometom treningu i natjecanju (iii) te da nisu pretrpjeli ozljedu donjih ekstremiteta u posljednjih 6 mjeseci. Svi ispitanici su proveli dva protokola zagrijavanja nakon kojih su izvodili testove. Protokoli zagrijavanja su se razlikovali samo u svom zadnjem dijelu. Na kraju jednog protokola se izvodio sprint 30 m, a na kaju drugoga sprint sa elastičnim užetom na maksimalnoj udaljenosti od hvatišta na kojoj ispitanik može napraviti jednak broj koraka kao i pri sprintu 30 m, a da ga uže ne povuče u nazad. Ispitanici su prije zagrijavanja ispunili upitnik za određivanje razine umora/oporavka. Sva istraživanja su provedena na prirodnoj travi na domicilnim terenima klubova koji su sudjelovali u istraživanju. Rezultati: Na ukupnom uzorku nogometaša (n=118) utvrđeno je pogoršanje izvedbe sprinta sa potencijacijskim podražajem između 0 i 5 metara (p<0,001; d=0,23; 1,36%), 20 i 25 metara (p=0,002; d=0,14; 0,67%) i 25 i 30 metara (p<0,001; d=0,35; 1,69%) te poboljšanje izvedbe slalom trčanja (p<0,001; d=0,38; 1,51%). Također, utvrđen je i pad horizontalnih mehaničkih parametara F0 (p=0,002; d=0,17; 2,00%), Pmax (p<0,001; d=0,20; 2,31%) i RFmax (p=0,002; d=0,19; 1,11%). Dvosmjernom mješovitom ANOVOM utvrđena je razlika u interakciji između protokola i grupa u sprintu između 0 i 5 metara (p=0,002; ηp 2=0,27; F=11,67), 5 i 10 metara (p=0,004; ηp 2=0,24; F=9,84), 15 i 20 metara (p=0,010; ηp 2=0,19; F=7,55), 20 i 25 metara (p=0,027; ηp 2=0,14; F=5,40) i 25 i 30 metara (p=0,014; ηp 2=0,18; F=6,79) te u brzini lopte kod udarca (p=0,049; ηp 2=0,51; F=4,19). Usporedbom parova kod grupe nogometaša dominantnih u teorijskoj maksimalnoj sili utvrđeno je pogoršanje izvedbe u sprintu između 0 i 5 metara (p=0,001; d=1,16; 4,5%) i poboljšanje izvedbe između 5 i 10 metara za (p=0,017; d=0,28; 1,26%). Poboljšanje je utvrđeno i u izvedbi slalom trčanja (p=0,007; d=0,59; 2,25%) kao i kod udarca (p=0,025; d=0,46; 2,88%). U horizontalnim mehaničkim parametrima utvrđen je pad F0 (p=0,001; d=0,94; 7,43%), Pmax (p<0,001; d=0,70; 6,37%) i RFmax (p=0,001; d=1,00; 3,59%) te povećanje V0 (p=0,001; d=0,33; 1,82%), DRF (p=0,002; d=0,89; 9,30%) i Vmax (p=0,020; d=0,29; 1,54%). Usporedbom parova kod grupe nogometaša dominantnih u teorijskoj maksimalnoj brzini utvrđeno je pogoršanje izvedbe u sprintu između 15 i 20 metara (p=0,035; d=0,67; 1,70%), 20 i 25 metara (p=0,022; d=0,69; 2,31%) i 25 i 30 metara (p=0,001; d=0,98; 3,37%), dok je kod slalom trčanja utvrđeno poboljšanje izvedbe (p=0,036; d=0,28; 1,04%). U horizontalnim mehaničkim parametrima utvrđen je pad V0 (p=0,002; d=0,69; 2,59%), DRF (p=0,020; d=0,36; 5, 50%) i Vmax (p=0,002; d=0,73; 2,44%). Grupa dominantna u maksimalnoj teorijsko sili je u sprintu brža na prvih 5 metara u oba protokola. U kontrolnom protokolu za 10,5% (p<0,001; d=2,25), a u potencijacijskom protokolu za 5,85% (p=0,004; d=0,96). Grupa dominantna u brzini je brža u svim preostalim dionicama po 5 metara u oba protokola. U kontrolnom protokolu od 5,11% do 6,31% (p<0,001; d=1,26 do 1,70), a u potencijacijskom protokolu od 2,6% do 4,11% (p=0,023 do <0,001; d=0,78 do 1,28). U izvedbi slalom testa grupa dominantna u sili je brža u potencijacijskom protokolu za 2,72% (p=0,025; d=0,69). Kod udarca grupa dominantna u brzini ima veću brzinu lopte u kontrolnom protokolu za 3,87% (p=0,042; d=0,59). Zaključak: Ovo istraživanje je pokazalo da je potencijacijski podražaj sprint sa horizontalnim elastičnim otporom značajno akutno poboljšava izvedbu trčanja u slalomu kod svih nogometaša, ali i specifično po grupama. To ukazuje da je potencijacijski podražaj vjerojatno poboljšao neuromuskularnu učinkovitost i reaktivnu sposobnost mišića. Potencijacijskim podražajem se značajno povećala maksimalna brzina lopte kod udarca i horizontalni mehanički parametri V0, DRF i Vmax samo kod nogometaša dominantnih u sili. To ukazuje na poboljšanu regrutaciju mišićnih vlakana i sinkronizaciju motoričkih jedinica nakon intenzivnog opterećenja. Potencijacijskim podražajem u prosjeku kod svih nogometaša dolazi do pogoršanja izvedbe na prvih 5 m i na zadnje dvije dionice po 5 m sprinta na 30 m, a kod dominantnih u sili samo prvih 5 m, dok kod dominantnih u brzini samo na zadnje tri dionice po 5 m. U prosjeku kod svih nogometaša potencijacijskim podražajem dolazi do pada F0, Pmax i RFmax, još veći pad navedenih parametara prisutan je kod grupe dominantne u sili, dok je kod grupe dominantne u brzini utvrđen pad V0, DRF i Vmax parametara. Pad performansi upućuje na zamor i neuromuskularnu inhibiciju, s većim utjecajem na početak sprinta kod dominantnih u sili te na kraj sprinta kod dominantnih u brzini. |
| Sažetak (engleski) | Objective: Lots of preconditioning activity have been used in studies of postactivation potentiation. So far, for the conditioning activity no one used an elastic resistance in the horizontal direction. The primary goal in soccer players is to determine the overall acute effect of sprinting with an elastic rope on the performance of sprinting, slalom running and kicking the ball, as well as the specific acute effect regarding the dominance of the horizontal mechanical profile. The secondary objective was to determine the differences in sprint, slalom and shot performance according to dominance in the horizontal mechanical profile.
Methods: 118 healthy soccer players from seven clubs of the Third Division Croatian Soccer League participated in the research. Inclusion criteria for participation in the study were: (i) male, older than 18 years, (ii) minimum 5 years of experience in soccer training and competition (iii) not having suffered an injury to the lower extremities in the last 6 months. All subjects performed two warm-up protocols, after which they performed tests. The warm-up protocols differed only in their last part. At the end of one protocol, a 30 m sprint was performed, and at the end of the second protocol was performed a sprint with an elastic rope at the maximum distance from the grip where the subject can take the same number of steps as during a 30 m sprint, without the rope pulling him back. Before the warm-up, the subjects filled out a questionnaire to determine the level of fatigue/recovery. All research were performed on natural grass at the home fields of the clubs that participated in the research.
Results: In the total sample of soccer players (n=118), a worsening in sprint performance with a potentiation stimulus between 0 and 5 meters (p<0.001; d=0.23; 1.36%), 20 and 25 meters (p=0.002; d=0.14; 0.67%) and 25 and 30 meters (p<0.001; d=0.35; 1.69%) and improvement in slalom running (p<0.001; d=0.38; 1.51%). Also, a decrease in the horizontal mechanical parameters F0 (p=0.002; d=0.17; 2.00%), Pmax (p<0.001; d=0.20; 2.31%) and RFmax was determined (p=0.002; d=0.19; 1.11%). Two-way mixed ANOVA revealed a difference in the interaction between protocol and groups in the sprint between 0 and 5 meters (p=0.002; ηp2=0.27; F=11.67), 5 and 10 meters (p=0.004; ηp2=0, 24; F=9.84), 15 and 20 meters (p=0.010; ηp2=0.19; F=7.55), 20 and 25 meters (p=0.027; ηp2=0.14; F=5, 40) and 25 and 30 meters (p=0.014; ηp2=0.18; F=6.79) and in the speed of the ball at soccer kick (p=0.049; ηp2=0.51; F=4.19). A pairwise comparison of a group of soccer players dominant in theoretical maximum force revealed a worsening of performance in the sprint between 0 and 5 meters (p=0.001; d=1.16; 4.5%) and improvement in performance between 5 and 10 meters by (p=0.017; d=0.28; 1.26%). Improvement was also found in the performance of slalom running (p=0.007; d=0.59; 2.25%) as well as in the soccer kick (p=0.025; d=0.46; 2.88%). A decrease in F0 (p=0.001; d=0.94; 7.43%), Pmax (p<0.001; d=0.70; 6.37%) and RFmax (p=0.001; d=1.00; 3.59%) was found in the horizontal mechanical parameters, but increase in V0 (p=0.001; d=0.33; 1.82%), DRF (p=0.002; d=0.89; 9.30%) and Vmax (p=0.020; d=0.29; 1.54%). By comparing pairs in the group of soccer players dominant in theoretical maximum velocity it was determined that the sprint performance worsening between 15 and 20 meters (p=0.035; d=0.67; 1.70%), 20 and 25 meters (p=0.022; d=0.69; 2.31%) and 25 and 30 meters (p=0.001; d=0.98; 3.37%), while an improvement in performance was found in slalom running (p=0.036; d=0.28; 1.04%). In horizontal mechanical parameters, a decrease in V0 (p=0.002; d=0.69; 2.59%), DRF (p=0.020; d=0.36; 5.50%) and Vmax (p=0.002; d=0.73; 2.44%). The group dominant in maximum theoretical force is faster in the sprint in the first 5 meters in both protocols. In the control protocol by 10.5% (p<0.001; d=2.25), and in the potentiation protocol by 5.85% (p=0.004; d=0.96). The group dominant in velocity is faster in all remaining sections of 5 meters in both protocols. In the control protocol from 5.11% to 6.31% (p<0.001; d=1.26 to 1.70), and in the potentiation protocol from 2.6% to 4.11% (p=0.023 to <0.001; d =0.78 to 1.28). In the performance of the slalom test, the force dominant group was faster in the potentiation protocol by 2.72% (p=0.025; d=0.69). In a soccer kick, the group dominant in velocity has a higher ball speed in the control protocol by 3.87% (p=0.042; d=0.59).
Conclusion: This research has shown that the potentiation stimulus sprint with horizontal elastic resistance significantly acutely improves the performance of running in slalom in all soccer players, but also specifically by groups. This indicates that the potentiation stimulus probably improved neuromuscular efficiency and muscle reactivity. The potentiation stimulus significantly increased the maximum speed of the ball at soccer kick and the horizontal mechanical parameters V0, DRF and Vmax only in force dominant group. This indicates improved recruitment of muscle fibers and synchronization of motor units after intense preconditioning activity. The potentiation stimulus causes, on average, a deterioration in the performance of all soccer players in the first 5 m and in the last two sections of a 5 m sprint on 30 m, and in those dominant in force only in the first 5 m, while in those dominant in velocity only in the last three sections of 5 m On average, in all soccer players, the potentiation stimulus causes a drop in F0, Pmax and RFmax, an even greater drop in the mentioned parameters is present in the force dominant group, while in the velocity dominant group, a drop in V0, DRF and Vmax parameters was found. The drop in performance points to fatigue and neuromuscular inhibition, with a greater impact on the beginning of the sprint in those dominant in force and at the end of the sprint in those dominant in velocity. |
