POVEZANOST TERENSKIH I LABORATORIJSKIH TESTOVA RAVNOTEŽE S USPJEŠNOSTI SKIJAŠA

Well developed proprioceptive abilities are the essential aspects of injury prevention and rehabilitation in many sports including alpine skiing. In our study we hypothesized that the field balance tests might be the factor that influences skier performance. The aim, therefore, was to determine which of the balance tests correlates most closely with skiing performance. The participants were 20 national alpine ski instructor candidates. The study design encompassed 3 simple laboratory balance tests (lateral and front-back tilts tests on the balance board, and hanging board balance test), 2 field balance tests (inner ski jump test and one leg carving test) and 3 official ski elements from Croatian Ski School (short slalom, giant slalom and off piste curves) that require high-level skiing skills. All elements were evaluated by three experienced independent judges. Multiple regression analysis singled out the inner ski jump balance test as the most important prediction factor for alpine skiing performance. We concluded that skiing coaches might find it useful to prescribe more field and specific balance training exercises to high level skiers, especially those which include inner ski jumps.Cilj ovog istraživanja bio je utvrditi povezanost između testova ravnoteže na balans daskama i na snijegu te uspješnosti u skijaškim elementima. Hipoteza, koja je bila postavljena prije istraživanja, glasila je da testovi ravnoteže mogu biti čimbenik utjecaja na uspješnost izvedbe skijaških elemenata. Uzorak ispitanika činilo je 20 kandidata za zvanje učitelja skijanja. Mjerni instrumentarij sadržavao je 3 testa ravnoteže na balans daskama, 2 testa ravnoteže na skijaškom terenu te 3 vrlo zahtjevna elementa hrvatske škole skijanja. Svi elementi su bili vrednovani od strane trojice iskusnih sudaca. Rezultati su pokazali da test ravnoteže na skijaškom terenu (skijanje na unutarnjoj skiji) ima najveći utjecaj na izvedbu skijaških elemenata, odnosno na skijašku uspješnost. Temeljem dobivenih rezultata moguće je skijaškim učiteljima i trenerima preporučiti da u svom radu sa skijašima, osobito natjecateljima, posebnu pažnju obrate na testove ravnoteže na skijaškom terenu, čime će doprinijeti većoj uspješnosti svojih skijaša. ravnoteža, učitelji skijanja, alpsko skijanj

Interaktivni ples: uzbudljiv način za povećanje tjelesne aktivnosti

Exergaming has become widely popular as a recreational activity at home and following that success new organized group programs are constantly being developed. The problem that emerges is the problem of the adequacy of exercise intensity for participants of different skills and fitness. Not many scientific studies investigated the physiological response of the computer-leaded interactive-dance performed in groups. That is why the aim of this study was to determine the physiological load level in children during an “iDance” class (“iDance”; Positive Gaming™). Twenty-one subjects (11 female, 10 male; age 10.7±1.6 years) participated in the study. During the class, heart rate (HR), energy expenditure and the perceived exertion were recorded. The results showed that the mean HR during the class was 147bpm (70.23% of the estimated maximal HR) which indicated that the children exercised at the moderate intensity. Nevertheless, 22% of the overall interactive-dance time was spent in a high-intensity zone. The energy cost values were 5.1 kcal/kg/h. In 86% of participants the activity was perceived as light and they reported being only moderately tired, which was encouraging from the motivational point of view as the measured physiological load was actually higher. In conclusion, we could say that, according to the estimated energy consumption and the exercise intensities recorded, the participation in “iDance” might elicit some positive changes in aerobic capacity. Also it might be a useful tool in weight management in obese children, but further longitudinal studies are needed to confirm that.„Exergaming“ odnosno tjelesna aktivnost u računalom vođenim igrama postala je široko popularna rekreacijska aktivnost i neprestano se razvijaju novi programi. No, javlja se problem primjerenosti intenziteta vježbanja za sudionike različitih razina vještina i tjelesnih sposobnosti. Nema mnogo istraživanja koja su proučavala fiziološki odgovor na računalno upravljani interaktivni ples koji se izvodi kao grupni program. Cilj ovog istraživanja bio je utvrditi razinu fiziološkog opterećenja u djece tijekom sata "iDance" ("iDance"; Positive Gaming™). Dvadeset i jedan ispitanik (11 djevojčica, 10 dječaka u dobi od 10,7 ± 1,6 godina) je sudjelovao u istraživanju. Tijekom sata su mjereni frekvencija srca, kalorijska potrošnja (procjenom) te subjektivni osjećaj opterećenja. Rezultati su pokazali da je prosječna frekvencija srca vježbača tijekom sata bila 147/min (70,23% od procijenjene maksimalne frekvencije srca) što ukazuje da su djeca vježbala umjerenim intenzitetom. Ipak, čak 22% ukupnog vremena interaktivnog plesa pleasči su proveli u zoni visokog intenziteta. Procijenjena kalorijska potrošnja je iznosila 5,1 kcal /kg /h. Unatoč tome, čak 86% sudionika doživjelo je aktivnost kao laganu i zabavnu i subjektivno su osjećali samo umjereni umor. To je ohrabrujuće u motivacijskom smislu jer su izmjerena fiziološka opterećenja zapravo bila viša. U zaključku, možemo reći da bi prema procijenjenoj kalorijskoj energetskoj potrošnji i intenzitetu aktivnosti sudjelovanje u "iDance" programima moglo imati pozitivan utjecaj na promjene u aerobnim sposobnostima. Također, to bi moglo biti korisno oruđe u reguliranju tjelesne mase u pretile djece, ali bi bilo potrebno provesti longitudinalno istraživanje za donošenje konačnog zaključka

MAKSIMALNI PRIMITAK KISIKA I BIOLOŠKA DOB KOD 12-GODIŠNJIH VESLAČA

This study was designed to examine the differences in VO max between 47 rowers of the same chronological 2 age (12-year-olds; mean ± SD 12,5 ± 0,3), but of varying levels of physical maturity. VO max was expressed in 2 absolute units (L/min), as the ratio standard mass-related units (mL/kg/min) and using the allometric model specific to the data set. Sexual maturity was visually assessed using indices of pubic hair developed by Tanner. The subjects were classified in pre-pubertal (Tanner stage 1), early-pubertal (Tanner stage 2), and mid-pubertal (Tanner stages 3 and 4) groups. They completed an incremental maximal treadmill test. Differences were compared using a one-way ANOVA. VO max (L/min) in 12-year-old rowers proved to be 2 greater in the mid-pubertal group than in both the earlypubertal (+19,7%) and pre-pubertal (+24,8%) groups. When expressed as a ratio standard (i.e. in mL/kg/min), VO max was +12,1% greater in the mid- and pre- 2 pubertals than in the earlypubertals. However, when compared using the appropriate scaling procedure, the VO max in mid-pubertal rowers was +14.5% greater than 2 in the early-pubertals, and +9,1% greater than in prepubertals. This suggests that factors other than body mass explain the greater aerobic power (as assessed by VO max) in more physically mature individuals of the 2 same chronological age. Allometric scaling of VO max in 2 the present study yielded a scaling coefficient for body mass of 0,68 (95% CI = 0,51-0,87). This finding reinforces the view that, in children, VO max increases 2 relative to body mass raised to the power of 0,67 rather than in direct proportion with body mass (i.e. mass1,0). In conclusion, using a log-linear scaling model to adequately control for body mass, we have demonstrated significant differences in VO max among 12-year-old 2 rowers of varying stages of puberty and, consequently, varying levels of maturity. Further research is needed in order to further explain the above-mentioned differences among groups of rowers exhibiting differing levels of maturity independent of body mass.Ova studija provedena je sa ciljem ispitivanja razlika u maksimalnom primitku kisika (VO2 max) izmedu 47 veslaca iste kronološke dobi (12-godišnjaci, AS±SD = 12,5±0,3), ali različite biološke dobi. VO2 max je izražen u apsolutnim jedinicama (L/min), u omjeru prema tjelesnoj masi (mL/kg/min) kao i uz upotrebu nelinearnog modela specifičnog za uzorak ispitanika. Biološka zrelost procjenjivana je vizualno korištenjem klasifikacije faza spolne zrelosti prema Tanneru. Ispitanici-veslači podijeljeni su u grupu veslača u pred-pubertetu (faza 1 po Tanneru), ranom pubertetu (faza 2 po Tanneru) i srednjem pubertetu (faze 3 i 4 po Tanneru). Mladi veslači podvrgnuti su progresivnom maksimalnom testu opterecenja na pokretnom sagu, a razlike su uspoređene upotrebom ANOVE. VO2 max (L/min) u 12-godišnjih veslaca pokazao se većim u veslača u srednjem pubertetu u odnosu i na one u ranom pubertetu (+19,7%), i posebno na one u predpubertetu (+24,8%). Izražen u odnosu na tjelesnu masu (mL/kg/min), VO2 max je bio +12,1% veci u veslaca u srednjem i pred-pubertetu u odnosu na one u ranom pubertetu. Međutim, kada su rezultati usporedeni upotrebom adekvatnog postupka normalizacije rezultata, VO2 max u veslača u srednjem pubertetu bio je +14.5% veci u odnosu na one u ranom pubertetu i +9,1% veci u odnosu na one u pred-pubertetu. Takvi rezultati sugeriraju da neki drugi čimbenici pored veće tjelesne mase objašnjavaju veću aerobnu snagu (procijenjenu sa VO2 max) kod biološki starijih pojedinaca iste kronološke dobi. Upotreba nelinearnog modela za pokazatelj VO2 max u ovoj studiji ukazala je na koeficijent skaliranja (eksponent) za tjelesnu masu 0,68 (95% CI = 0,51-0,87). Ovo otkriće pojačava pretpostavku da se, kod djece, VO2 max povecava u odnosu na tjelesnu masu sa eksponentom 0,67, a ne u direktnom odnosu sa tjelesnom masom (tj. masa 1,0). Zaključno, korištenjem nelinearnog modela u svrhu adekvatne kontrole tjelesne mase dokazali smo značajne razlike u VO2 max izmedu 12-godišnjih veslaca razlicitih po biološkoj dobi. Daljnja istraživanja su neophodna u svrhu detaljnijeg objašnjenja gore spomenutih razlika između grupa veslača razlicite biološke dobi neovisno o tjelesnoj masi

RETROSPECTIVE ANALYSIS ABOUT THE INJURIES IN KINESIOLOGY STUDENTS – COMPARISON OF TWO STUDY PROGRAMS

Glavni cilj ovog istraživanja bio je utvrditi postoji li razlika u učestalosti i specifičnosti ozljeđivanja studenata Kineziološkog fakulteta koji su studirali prema starom (integriranom četverogodišnjem) i onih koji studiraju prema novom petogodišnjem (3+2) programu studija. Istraživanje je provedeno na uzorku od 77 ispitanika (36 studentica i 41 studenta) Kineziološkog fakulteta Sveučilišta u Zagrebu koji studiraju prema novom, petogodišnjem programu studija. Studenti su na kraju osmog semestra ispunili posebni anketni upitnik. Njihovi su rezultati uspoređeni s onima dobivenim na studentima koji su studirali prema starom studijskom programu. Prema rezultatima, učestalost ozljeđivanja studenata Kineziološkog fakulteta koji su studirali prema novom ili starom programu studija vrlo je visoka. U prosjeku svaki se anketirani student ozlijedio barem jedan put u četiri godine studija. Pri tome prevladavaju ozljede zglobova, pogotovo donjih ekstremiteta, a studenti se češće ozljeđuju od studentica. Distribucija ozljeda po godinama studija kod studenata koji su studirali prema starom ili prema novom programu studija vrlo je slična, a rizik ozljeđivanja se u obama generacijama znatno smanjuje tek na četvrtoj godini, što je najvjerojatnije odraz smanjenja broja obveznih praktičnih predmeta. Uvođenje novog programa, dovelo je do znatnog smanjenja rizika ozljeđivanja studenata na sportskoj gimnastici uz istovremeno povećanje rizika ozljeđivanja na rukometu. Osim toga, ozljede koje su pretrpjeli studenti novije generacije lakše su naravi te znatno ne utjeću na tijek njihova studiranja. Nadalje, studenti novije generacije u većem se omjeru ozljeđuju na nastavi, dok su se oni koji su studirali prema starom programu češće ozljeđivali tijekom samostalnog pripremanja ispita. Dva puta dokazana visoka učestalost ozljeđivanja studenata Kineziološkog fakulteta ukazuje na potrebu za uvođenjem određenih promjena u novom programu studija (3+2). U tom smislu vrijedilo bi pokušati sa dodatnim smanjenjem broja studenata po grupi, pogotovo na vježbama, kada se studenti najčešće i ozljeđuju. Osim toga, dodatno povećanje broja predavaonica i sportskih dvorana (terena), u smislu jutarnjeg rasporeda nastave moglo bi spriječiti nakupljanje umora tijekom dugih radnih dana te indirektno smanjiti utjecaj umora na mogućnost ozljede studenataThe main goal of this study was to search for possible differences in frequency and specificity of injuries between the Kinesiology students who attended the Faculty of Kinesiology, University of Zagreb according to the old study program (4 years), and those who are attending the new study program (5 years). The sample was composed of 77 students (36 female and 41 male) attending the new study program, who were compared to the previously studied sample. They filled up a questionnaire at the end of their eight semester. Their results where than compared with those of the students who attended the old study program. The results showed a high injury rate in both samples. In average, every examinee suffered at least one injury during his/her study. Mostly, they injured their lower extremities, and the male students where injured more often. The injury risk in both generations decreased only in the 4th study year, probably because of less compulsory practical subjects. The implementation of the new study program resulted in a biggest injury risk during team handball, and smaller risk during sport gymnastics. Besides, the injuries sustained by the students who attended the new study program, were less serious with much lower implications for the regularity of their study. Further, numerous students attending the new study program suffered an injury during the classes, while the ones attending the old study program where mostly injured when preparing the exam. Since the injury rate was very high in both groups, there is a need to introduce some changes in the new study program in order to decrease the injury risk of Kinesiology students. An additional reduction in number of students per group, especially for the practical classes, may be helpful. Besides, a bigger number of classrooms as well as sport halls may implicate a morning schedule, giving the students more time to rest before their afternoon practice, eventually leading to a smaller number of injuries due to fatigu

THE EFFECTS OF AEROBIC AND ANAEROBIC PHYSICAL ACTIVITY ON INSULIN DOSE REDUCTION IN DIABETICS

Kako bi spriječili hipoglikemiju i hiperglikemiju tijekom vježbanja, dijabetièari moraju prilagoditi svoju prehranu i doziranje inzulina. Cilj ovog istraživanja bio je utvrditi da li i u kojoj mjeri aerobna i anaerobna tjelesna aktivnost utječe na razinu glukoze u krvi i potreban broj jedinica inzulina kod pacijenata oboljelih od dijabetesa tipa 1 koji prethodno nisu redovito vježbali. Trideset ispitanika (prosječne dobi 26,8±8,6; starosti 16-49 godina), 17 ženskih i 13 muških, pohaðali su jedan mjesec treninga koji se sastojao ili od dominantno aerobnog tipa treniranja (34% ispitanika) ili od anaerobnog tipa treniranja (20% ispitanika) ili mješovitog (46% ispitanika. Svi ispitanici bolovali su od dijabetesa tipa 1 i primali su inzulinsku terapiju. Vrijednosti HbA1c, prosječne visine glukoze u krvi i dnevnog broja jedinica inzulina bile su zabilježene prije i poslije razdoblja treniranja. Rezultati Student t-testa za nezavisne uzorke pokazali su da su srednje vrijednosti HbA1c značajno smanjene (7,95±0,73 vs. 7,74±0,56%, p < 0,001). Takoðer, smanjenje dnevne potrošnje inzulina bilo je statistièki znaèajno (52,1±6,0 jedinice inzulina vs 42,68±5,2 jedinica, p < 0,001), kao i GUK (8,25±0,78 vs 7,84±0,68 mmol/L, p < 0,001). Nije bilo razlika izmeðu aerobnog, anaerobnog i mješovitog tipa treninga, ali zbog problema malog uzorka ne možemo tvrditi da one ne postoje (ANOVA rezultati: Wilks Lambda = 0715 , F (6,22) = 0.679, p = 0.674). Iako nismo bili u mogućnosti utvrditi odnos izmeðu vrste aktivnosti i smanjenja promatranih vrijednosti, uspjeli smo potvrditi smanjenje u odnosu s volumenom aktivnosti. Ne-parametarski korelacijski test potvrdio je statistički značajne korelacije izmeðu volumena dnevne tjelesne aktivnosti u minutama i smanjenje HbA1c (Spearman R= 0,57); prosječnog smanjenja razine glukoze u krvi (Spearman R = 0,44) i dnevnog broja jedinica inzulina koja se uzima (Spearman R = 0,54).To prevent hypo and hyperglycemia during exercise, diabetics need to adjust their nutrition and insulin dosage. The aim of this study was to determine whether and how physical activity affects the blood glucose levels and the required amount of insulin in previously sedentary patients suffering from type 1 diabetes. Thirty subjects (mean age 26,8±8,6; range 16-49 years), 17 female and 13 male, underwent the one month training procedure consisting of either dominantly aerobic type of training (34% of subjects) anaerobic type of training (20% of subjects) or mixed (46% of subjects). All of the subjects suffered from diabetes mellitus, type 1 and were receiving insulin therapy. The values of HbA1c, the mean blood glucose concentration and the number of insulin units received daily were recorded before and after the exercise intervention. The monitored parameters were measured once again after the intervention. The results of the Student t-test for independent samples showed that the mean values of HbA1c decreased significantly (7,95±0,73 vs. 7,74±0,56%; p<0,001). Similarly, the decrease in the daily insulin unit consumption was also statistically significant (52,1±6,0 Ins units vs. 42,68±5,2 units; p<0,001), and mean blood glucose as well (8,25±0,78 vs. 7,84±0,68 mmol/L; p < 0,001). No differences were found but as for the problem of the small number of subjects in each group we could not claim that those do not exist (ANOVA results: Wilks Lambda = 0,715, F (6,22) = 0,679; p = 0,674). Even though we were unable to determine the relation between the type of the activity and the decrease of the monitored parameters, we did manage to confirm the relation of those with the activity volume. Nonparametric correlation test confirmed statistically significant correlations between the volume of the daily physical activity in minutes and the decrease in HbA1c (Spearman R= 0,57); mean blood glucose decrease (Spearman R= 0,44) and the daily insulin units used (Spearman R= 0,54