Objektyviai nustatyto paauglių berniukų savaitinio fizinio aktyvumo rezultatų analizė

Tyrimo pagrindimas ir hipotezė. Pasaulinėje mokslo praktikoje fizinio aktyvumo (FA) objektyvūs nustatymo metodai naudojami vis dažniau, tačiau Lietuvoje aptikti tokio pobūdžio tyrimų mums nepavyko. Taigi mes atlikome bandomąjį tyrimą objektyviai nustatydami paauglių FA ir norime pradėti plėtoti Lietuvoje tikslesnę FA nustatymo metodiką. Tikslas – išanalizuoti objektyviai nustatyto paauglių berniukų savaitinio fizinio aktyvumo rezultatus. Metodai. Mokinių FA nustatytas naudojant Tri-axis ActiTrainer Activity Monitor prietaisus. Berniukų buvo prašoma prietaisus nešioti savaitę kas minutę fiksuojant fizinę veiklą. Fizinio aktyvumo lygmuo buvo nustatomas taikant MET’ų skaičiavimo metodą, kai fizinė veikla trunka vienu metu ilgiau negu dešimt minučių. Analizuojant fizinio aktyvumo duomenis, FA standartizuotas pagal energijos suvartojimą, t. y. intensyvumo lygius. Pagal juos tiriamieji buvo suskirstyti į FA grupes pagal didelio ir vidutinio FA dažnį per savaitę. Rezultatai. Tyrimo rezultatai parodė, kad visi tiriamieji patiria mažą FA kiekvieną dieną, vidutinį kasdien patiria 59,6% tiriamųjų. Tuo tarpu kasdien didelį FA patiriančių berniukų nenustatyta. Tiriamieji patiria vidutinį FA dažniausiai 5–7 dienas per savaitę, o didelį – nuo 1 iki 3 dienų per savaitę ir atskirais atvejais 4 ar 6 dienas per savaitę. Didžiąją dalį bendro FA sudaro mažo intensyvumo fizinė veikla – tai sudaro 79,8% nuo bendro per savaitę patirto FA, kai vidutinis FA sudaro 18,8%, didelis FA – 1,4%. Aptarimas ir išvados. Didelį FA patiriančių berniukų bendras savaitinis FA didesnis, negu jo nepatiriančių berniukų. O patiriant didelį FA daugiau negu dvi dienas per savaitę bent po 10 minučių, reikšmingai padidėja bendro savaitinio FA apimtis, ir šie tiriamieji turėjo mažesnį KMI. Berniukams nepatiriant vidutinio FA bent šešias dienas per savaitę, sumažėja bendras savaitinis FA.Research background and hypothesis. The objective methods for measuring PA are used more and more widely in various research studies all over the world. To our best knowledge, this pilot study is the first attempt in Lithuania to objectively assess physical activity of adolescents with an ambition to develop a more accurate methodology in assessing physical activity. Research aim of this study was to analyze the objectively measured weekly physical activity results of adolescent boys. Research methods. The PA of schoolboys was measured using Tri-axis ActiTrainer Activity Monitors. Boys were asked to wear the monitors for the whole week. The level of the intensity of PA was determined by calculating energy consumption in METs. Based on the frequency of vigorous and moderate PA per week, the participants of this study were devided into PA groups. Research results. All of the schoolboys experienced LPA on each of the assessed days. MPA on each day was experienced by 59.6 % of the boys. No participants achieved VPA on a daily basis. The frequency of MPA and VPA experienced most often was 5–7 and 1–3 days per week, respectively. The total PA measured during the week was largely comprised by LPA, i. e. 79.8%; MPA and VPA were 18.8 and 1.4%, respectively. Discussion and conclusion. Boys who achieve VPA, have a greater total PA during the week than those boys who do not experience VPA. If boys achieve VPA on more than 2 days during the week, even if it is just for 10 min, there is a significant increase in the total amount of weekly PA as well as a decrease in their body mass index (BMI). Boys’ who do not experience MPA at least for 6 days/week, the total amount of weekly PA decreases

Funkcinės būklės rodiklių kaita taikant jėgos ištvermės krūvius

Tyrimo pagrindimas ir hipotezė. Skirtingos trukmės jėgos ištvermės fizinių krūvių suminis ir liekamasis poveikiai širdies ir kraujagyslių sistemai yra mažai nagrinėti. Tikslas – nustatyti lengvaatlečių raumenų, širdies ir kraujagyslių sistemų funkcinės būklės rodiklių kaitą mezociklo metu, kai sportininkai du mikrociklus atlieka didelius jėgos ištvermės krūvius, o trečią skiria aktyviam poilsiui. Metodika. Funkcinė būklė vertinama pagal tris rodiklių grupes: 1 – raumenų funkcinio pajėgumo (trišuolis iš vietos); 2 – ŠKS funkcinės būklės (arterinio kraujo spaudimo rodikliai); 3 – organizmo atsigavimo po fizinio krūvio. Tyrimo metu visi respondentai atlikdavo modifikuotą Rufjė fizinio krūvio ir anaerobinio krūvio mėginį (30 s vertikalūs šuoliai didžiausiomis pastangomis). Dvylika standartinių EKG derivacijų buvo registruojama ir analizuojama kompiuterine EKG analizės sistema „Kaunas–krūvis“. Rezultatai. Raumenų funkcinio pajėgumo rodikliai vienareikšmiškai blogėja tada, kai du mikrociklus sportininkai atlieka didelės apimties jėgos ištvermės krūvius, o atsigavimo greitis po šių fizinių krūvių yra individualus. Dėl didelės apimties jėgos ištvermės krūvių sumažėjusios periferinių kraujagyslių tonuso reguliavimo galimybės yra kompensuojamos centrinio kraujotakos organo širdies funkcija – sistolinio kraujospūdžio padidėjimu. Širdies ir kraujagyslių sistemos funkciniai rodikliai (ŠSD, AKS, elektrokardiogramos JT intervalo ir intervalų JT/RR santykio, atsigavimo pusperiodžiai (½T) po fizinio krūvio mėginio) rodo organizmo funkcinės būklės pokyčius ir teikia informacijos apie suminio bei liekamojo nuovargio požymius. Aptarimas ir išvados. Raumenų funkcinio pajėgumo rodikliai vienareikšmiškai blogėja tada, kai du mikrociklus sportininkai atlieka jėgos ištvermės krūvius, o atsigavimo greitis po šių fizinių krūvių yra individualus. Sumažėjusios periferinių kraujagyslių tonuso reguliavimo galimybės yra kompensuojamos centrinio kraujotakos organo širdies funkcija – sistolinio kraujospūdžio padidėjimu.Research background and hypothesis. There are few studies about the variables of the duration of powerendurance workloads and their total and residual effects. Research aim was to evaluate the changes in the functional state indices of muscular and cardiovascular systems while two training micro-cycles were designed to develop power-endurance abilities, and the third one was appointed for active rest. Research methods: Seven sprint athletes performed two micro-cycles of concentrated power-endurance type loads and one micro-cycle was appointed for recovery. Three groups of indices were chosen: muscular power; cardiovascular indices and indices of recovery. 12-leads ECG was registered during the Ruffier test and 30 s vertical jumping tests. Research results. Under the influence of two training micro-cycles using concentrated power endurance workloads muscular power deteriorated and the recovery rate was individual. After two training micro-cycles the effect of total fatigue caused an increased biological efforts to perform the locomotion task and cardiovascular changes were more expressed than before training. Seven days was a too short period of time so that the changes in the indices caused by total effect of training would return to the baseline values again. Discussion and conclusions. Reduced abilities in the regulation of peripheral vascular tone after heavy training could be compensated by the changes in the cardiac function, i. e. by an increase in systolic blood pressure. Cardiovascular indices could be useful for describing changes in the functional state of athletes under the influence of training

Vyresniųjų klasių mergaičių fizinio pajėgumo kaita

Tyrimo pagrindimas ir hipotezė. Lietuvoje per pastaruosius penkerius metus 10–12 klasių mergaičių fizino pajėgumo kitimo ilgalaikių tyrimų nepavyko rasti. Netiesioginiai šių ypatumų tyrimai parodė, kad Lietuvos moksleivių fizinio pajėgumo kitimas turi neigiamų tendencijų ir tarp moksleivių vyrauja sėdima gyvensena. Tikslas – nustatyti Kauno miesto mergaičių fizinio pajėgumo rezultatų kitimo ypatumus 10–12 klasėje. Metodai. Tirtos Kauno miesto 10 klasės mergaitės (n = 244), tyrimo metu buvusios mokykloje ir galinčios atlikti reikiamus Eurofito testus. Duomenys buvo registruojami 2 kartus per mokslo metus – rugsėjo ir gegužės mėnesiais. Ilgalaikis tyrimas pradėtas 10 klasės rudenį ir tęsėsi iki 12 klasės pavasario. Moksleivės atliko Eurofito testus (10 × 5 m bėgimo šaudykle, šuolio į tolį iš vietos, „Sėstis ir gultis“, 20 m ištvermės bėgimo šaudykle). Rezultatai. Nuo 10 klasės rudens iki 12 klasės pavasario mergaičių skirtingų Eurofito testų rezultatų kaita buvo nevienoda. Tyrimas parodė, kad 10–12 klasėse reikšmingai pakito tik ištvermės testo rezultatai, o 11 klasėje pastebėtas staigiosios jėgos pagerėjimas ir liemens jėgos rezultatų svyravimas. Aptarimas ir išvados. Lyginant 10 ir 12 klasių mergaičių fizinį pajėgumą nustatyta, kad jis pagerėja tik atliekant 20 m šaudyklinio bėgimo testą, o 11 klasėje reikšmingai pagerėja staigioji jėga.Research background and hypothesis. During the last five years Lithuanian long-term research related to the peculiarities of changes in physical fitness among 10-12th-grade schoolgirls has not been found. Other research in Lithuania showed negative tendencies of physical fitness changes of Lithuanian schoolchildren and prevailing sedentary lifestyle. Research aim was to determine peculiarities of change results in physical fitness among Kaunas schoolgirls (10–12th grades). Research methods. The present research included 10th-grade schoolgirls (n=244) of Kaunas city who were at school during the research and were able to perform the necessary Eurofit tests: 10×5 m Shuttle run, Standing Broad Jump, Sit ups in 30 seconds, 20 m endurance Shuttle run. Research results. Changes in results of Eurofit tests performed from 10th grade autumn to 12th grade spring were different. Results of girls (10–12th-grade) in 10×5 m shuttle run test did not change (p>0.05). Results of standing broad jump improved significantly in Grade 11 (p<0.05). Results in 20 m endurance shuttle run test improved in Grade 12 (p<0.05). Results in Sit ups in 30 seconds test improved in spring. Significant differences were found between 10 and 12thgrade schoolgirls spring Sit ups in 30 seconds test results, and 10 and 11th-grade autumn results. Discussion and conclusions. Comparison of physical fitness of 10 and 12th-grade girls showed that it improved only in 20 m endurance shuttle run, in the 11th grade explosive strength of schoolgirls significantly improved

Relation between indices of functional state of central nervous system and anaerobic performance

The purpose of this study was to find out the relation between the indices of anaerobic performance and the indices of the functional state of central nervous system. The Wingate Test, which is widely accepted in the assessment of anaerobic performance abilities, was used in this study. A special computer program was used for the assessment of changes in the frequency of movement during the Teping-Test. The results of the two groups of well-trained athletes in sprint or endurance events were compared. We have found the close relation between the changes in the frequency of movement during the Teping test and the changes of power during the Wingate Test. We conclude that there is a close relation between the anaerobic performance abilities of high-trained sportsmen and the functional state of central nervous system. The Teping Test can be useful for the evaluation of changes in anaerobic performance in cases of a short-term period before a competition

Objektyviai nustatytas paauglių berniukų savaitinis fizinis aktyvumas ir jo sąsajos su sveikata susijusiu fiziniu pajėgumu

Research background and hypothesis. The objective methods of measuring physical activity (PA) are used more and more widely in various types of research. However, in Lithuania there is a lack of such studies with adolescents. Thus, we conducted a pilot study to objectively measure boys’ PA and to develop a more accurate PA assessment methodology in Lithuania. The purpose of this study was to analyse the objectively measured adolescent boys’ weekly physical activity and its relation to their body composition and physical fitness. Research methods. The participants of this study were 104 healthy adolescent boys. Physical activity of schoolboys was measured using actigraphs (Tri-axis ActiTrainer Activity Monitors). The level of the intensity of physical activity was determined by calculating energy consumption in MET’s. Low PA (LPA) equals up to 3 MET’s, moderate PA (MPA) – 3–6 MET’s, and vigorous PA (VPA) – 8 or more METs. Based on the frequency of VPA and MPA per week, the participants of this study were divided into physical activity groups. For health-related physical fitness assessment the following tests were used: body composition (using TANITA Body Analyser, TBF-300); flexibility (sit and reach test, Eurofitas, 2002), power (vertical jump was measured using a jump parameter gauge (SBM-1), muscular strength and endurance (modified push-up test (Suni et al., 1994)). Research results. All of the schoolboys demonstrated LPA on each day of the assessment. MPA on each day was experienced by 59.6% of the boys. No participants achieved VPA . The most frequent MPA and VPA were observed 5–7 and 1–3 days per week, respectively. Results of body composition indicated that boys experiencing VPA had lower body fat mass compared to those who experienced only MPA and LPA (p<0.05). Analysis of physical fitness results indicated that boys who experienced VPA were better muscular in strength and endurance test (p<0.05), but results of high jump and sit and reach test were not significantly different. Discussion and conclusion. Boys who experienced VPA at least for 3 days/week demonstrated better muscular strength and endurance results and had lower body fat content (%) (p<0.05). For boys who did not experience MPA at least for 6 days/week, the total amount of weekly physical activity decreased and they could not produce better results in strength and endurance test (p<0.05). Better results of boys’ muscular strength and endurance were significantly related to their body lower BMI (r=0.279; p<0.05) and fat mass (r=0.387; p<0.01)

Greitumą ir ištvermę lavinančių sportininkų raumenų darbingumo rodiklių kaita atliekant 30 s trukmės vertikalaus šuoliavimo testą

Tyrimo pagrindimas ir hipotezė. Vertinant sportuojančiųjų parengtumą ir jo pokyčius po treniruotės etapo taikomi fizinio krūvio mėginiai, kurių metu greitai pavargstama. Suformuluotas aiškus metodinis reikalavimas, kad testavimo procedūra neturi modifikuoti treniruotės tikslų. Gerai žinoma, kad darbingumo vertinimo testų specifiškumas yra reikšmingas tada, kai norime palyginti skirtingų tiriamųjų grupių darbingumą. Tikslas – nustatyti sprinto ir ištvermės bėgikų raumenų darbingumo rodiklių kaitos ypatybes atliekant 30 s trukmės vertikalaus šuoliavimo testą. Metodai. Buvo tiriami lengvaatlečiai bėgikai (sprinto ir ištvermės grupės). Tiriamieji atliko 30 s trukmės vertikalaus šuoliavimo testą didžiausiomis pastangomis. Sportininkui šuoliuojant ant kontaktinės platformos, vertinome šuolio aukščio, santykinio galingumo, jų mažėjimo spartos, atremties fazės trukmės rodiklius, skaičiavome visų atliktų šuolių aukščio sumą. Rezultatai. Visos šuolių serijos metu abiejų tiriamųjų grupių, šuolių aukščio vidutinės reikšmės, užregistruotos kas penkias sekundes, mažėjo. Lyginant abi tiriamųjų grupes, šuolių aukščio vidutinių reikšmių skirtumas išliko statistiškai reikšmingas (p<0,05) visos šuolių serijos metu. Abiejų tiriamųjų grupių raumenų santykinio galingumo kaita serijos metu turėjo panašią tendenciją. Šuolių serijos metu nustatėme, kad sprinterių grupėje šuolio aukštis ir santykinis galingumas mažėjo didesne sparta nei ištvermės bėgikų. Viso šuolių testo metu atsispyrimo trukmė buvo kur kas ilgesnė ištvermės bėgikų grupėje. Aptarimas ir išvados. Nepaisant kai kurių metodinių apribojimų, vertikalaus šuoliavimo testas, sukuriantis greitai besivystančio nuovargio sąlygas, leidžia vertinti sportuojančiojo raumenų santykinio galingumo, nuovargio ir jų kaitos ypatybes. Prie greitumo krūvių adaptavęsi asmenys pasiekia reikšmingai didesnių raumenų darbingumo rodiklių nei ištvermės šakų sportininkai. Atlikdami fizinio krūvio užduotis greitai besivystančio nuovargio sąlygomis ištvermės bėgikai mažėjantį raumenų susitraukimo galingumą kompensuoja atremties fazės trukmės pailginimu daugiau nei sprinteriai.Research background and hypothesis. According the methodological requirement testing procedures do not modify the main training objectives. It is well known that specificity of performance assessment tests is important if we want to compare performance of different groups tested. Research aim was to find out the peculiarities of muscular performance indices in sprint and endurance cohorts while performing a 30-s vertical jump test. Research methods. The participants of the study were two groups of athletes, i. e. sprint and endurance runners. The participants of the study performed a 30-s vertical jumps test with maximal efforts. The sum of height of all jumps was calculated by a special computerized program and the values in height of jumps, contact time and relative power at onset of workload and at each 5 seconds of the test were analyzed. Research results. The difference between the cohorts in jumps height was statistically significant (p<0.05) during the whole series of jumps. Athletes’ adaptation to speed-power type of exercising produced higher anaerobic muscle performance indices while performing 30-s duration jumps test. Endurance runners usually demonstrate lower results in jumping than sprint- athletes and they compensate reduced muscular power with prolonged duration of take-off. Discussion and conclusions. Despite some methodological limitations the results of this study show that the assessment of muscular performance indices allows assessing the peculiarities of dynamics of relative muscle power and fatigue

Širdies ir kraujagyslių sistemos funkcijos aktyvėjimo ypatybės darant dozuoto ir maksimalaus fizinio krūvio mėginius

The problem of evaluating the mobilization of body functioning during exercise combines two questions: first, the velocity of adaptation at onset of exercise, and second, to what extent the body function was mobilized. the aim of this study was to find out the peculiarities in mobilization of cardiovascular function during constant-load and all-out exercise tests in non-athletes and sportsmen: cohorts of sprinters, endurance and combat athletes. Every subject underwent a Roufier's test (30 squats per 45 seconds), a 30-second duration maximal vertical jump test, and a bicycle ergometry (graded stress). Indirect arterial blood pressure measurements were taken from the arm with a sphygmomanometer and standard -size arm cuff and variuos indices registered in 12-lead electrocardiogram (ECG) using a computerized ECG analysis system "Kaunas-load" were analyzed. The results obtained during the study showed that the change in ratio of JR/RR intervals of ECG allows assessing the dynamics of mobilization of cardiovascular system during the exercise tests or workouts. The greater mobilization of cardiovascular system when performing constant-load exercise tests is rather characteristic for non-athletes than sportsmen's cohorts. Constant-load exercise tests rather than all-out exercise tests are more suitable for assessments of individual peculiarities or differences between the cohorts. The individual peculiarities in velocity of adaptation of cardiovascular system at onset of exercise can be evaluated making use of the index of velocity of adaptation, which represents the difference between the relative changes of JT and rr intervals of ECG. Velocity of adaptation at onset of exercise depends on the residual effects of training but not on the type of exercise test

Electrochemical SEIRAS Analysis of Imidazole-Ring-Functionalized Self-Assembled Monolayers

An essential amino acid, histidine, has a vital role in the secondary structure and catalytic activity of proteins because of the diverse interactions its side chain imidazole (Im) ring can take part in. Among these interactions, hydrogen donating and accepting bonding are often found to operate at the charged interfaces. However, despite the great biological significance, hydrogen-bond interactions are difficult to investigate at electrochemical interfaces due to the lack of appropriate experimental methods. Here, we present a surface-enhanced infrared absorption spectroscopy (SEIRAS) and density functional theory (DFT) study addressing this issue. To probe the hydrogen-bond interactions of the Im at the electrified organic layer/water interface, we constructed Au-adsorbed self-assembled monolayers (SAMs) that are functionalized with the Im group. As the prerequisite for spectroelectrochemical investigations, we first analyzed the formation of the monolayer and the relationship between the chemical composition of SAM and its structure. Infrared absorption markers that are sensitive to hydrogen-bonding interactions were identified. We found that negative electrode polarization effectively reduced hydrogen-bonding strength at the Im ring at the organic layer–water interface. The possible mechanism governing such a decrease in hydrogen-bonding interaction strength is discussed

Šešiolikamečių berniukų fizinio aktyvumo ir su sveikata susijusio fizinio pajėgumo ryšiai

It is well established that regular physical activity (PA) has many short- and long-term benefits for children’s health. Physically active children are more physically fit than their physically inactive counterparts. Insufficient physical fitness of adolescents is one of the risk factors for chronic diseases and has a tendency to be carried over into adulthood. Research aim was to examine health-related physical fitness in low, moderate and vigorous physical activity categories among 16-year-old schoolboys. The participants were 155 healthy schoolboys of the 10th grade from secondary schools of Kaunas (Lithuania). Their physical activity was measured by a modified short form of the International PA Questionnaire (IPAQ) (Craig et al., 2003). The respondents were divided in three PA categories: high (vigorous) (VPA) (n = 43), moderate (MPA) (n = 63), and low (LPA) (n = 49). Physical fitness tests were performed to measure participants’ flexibility (by sit-and-reach test) (Eurofit, 1993), power (by vertical jump test), and muscular strength and endurance (by modified push-up test) (Suni et al., 1994).There were no significant differences between the boys in different PA groups in respect of anthropometrical and body composition parameters (p > 0.05). The results of health-related physical fitness tests were significantly better of the VPA group boys (p < 0.05). The total volume of PA correlated with all healthrelated physical fitness components that were measured (r = 0.23–0.38, p < 0.01). We may conclude that health-related physical fitness is positively related to the total amount of physical activity in 16-year-old schoolboys