Marjeta Kovač

Associations of objectively assessed sleep and physical activity in 11-year old children

Abstract Aim: Objective methods were used to evaluate children’s sleep and physical activity over several days in order to test the hypotheses that: (1) low average sleep duration and/or sleep efficiency are linked to a low amount of physical activity; and (2) a reduction in sleep quantity and/or sleep efficiency during the night is followed by a decrease in physical activity the following day. Methods: This is a multi-centre, observational study involving 276 children, aged 10.5–12 years, from diverse urban settings in Croatia, Slovenia and the US. Sleep and activity were monitored for 2–6 days (median = 4) using the Sensewear Armband™ multi-sensor body monitor. Results: While average sleep duration and efficiency were unrelated to physical activity, within-subjects associations revealed that an extra hour spent in bed during the night was followed by a 16-minute decrease in moderate-to-vigorous physical activity (p < 0.001). This was accompanied by a 4.5 kJ/kg and 5.9 kJ/kg lower total daily energy expenditure in boys and girls, respectively (p < 0.001). Conclusions: This study found no evidence for a link between short sleep and low or reduced physical activity.

School day and weekend patterns of physical activity in urban 11‐year‐olds: A cross‐cultural comparison

This multi‐center study was conducted to objectively evaluate energy expenditure and physical activity (PA) patterns on school days and weekends in urban 11‐year‐olds.

Frequency and characteristics of excuses given by students attending special sports classes of secondary school to avoid participating in physical education class

Vpliv Šolanja v Gimnazijskih Športnih Oddelkih na Pogostost in na Značilnosti Opravičevanja Pri Športni Vzgoji Namen: Namen raziskave je ugotoviti, ali obstajajo razlike med opravičevanjem dijakov športnikov in dijakov, ki se šolajo v običajnih gimnazijskih oddelkih, cilj pa preučiti vpliv šolanja v športnih oddelkih na pogostost in na značilnosti opravičevanja pri športni vzgoji. Metode: Uporabljeni vprašalnik ugotavlja pogostost opravičevanja, razloge za dejanska in namišljena opravičila ter dejavnosti, ki jih dijaki opravljajo v času, ko so opravičeni. Vzorec je obsegal 560 dijakov, in sicer 210 dijakov športnih oddelkov in 350 dijakov običajnih gimnazijskih oddelkov. Pomembnost stratifikacijskih spremenljivk (vrsta oddelka, letnik šolanja, spol, splošni učni uspeh) za pojasnjevanje pogostosti opravičevanja pri športni vzgoji smo ocenili z ordinalno regresijsko analizo s povezovalno funkcijo logit. Rezultati Najmočnejša posamezna pokazatelja pogostosti opravičevanja dijakov pri športni vzgoji sta spol in letnik; največjo verjetnost za opravičevanje imajo dekleta in dijaki 4. letnika. Dijaki športnih oddelkov se ne opravičujejo statistično značilno pogosteje kot dijaki gimnazijskih oddelkov. Mediana odsotnosti dijakov in dijakinj športnih oddelkov je med 1 uro in 5 urami ter med 6 in 10 urami letno ter je višja kot pri dijakih v običajnih oddelkih, vendar ne pri dijakinjah. Opravičevanje športnikov ni odvisno niti od športne panoge, s katero se ukvarjajo, niti od obsega treninga in športne uspešnosti, pač pa od spola. Večje možnosti za pogostejše opravičevanje imajo fantje. Najbolj pogosti dejanski razlogi za opravičevanje so poškodbe, bolezen in učenje za drug predmet. Enako kot njihovi vrstniki tudi dijaki športniki med opravičenostjo najpogosteje opazujejo pouk ali se učijo za drug predmet. Zaključek: Sistem opravičevanja je preohlapen, učitelji pa ne zaposlijo dijakov, ko ne vadijo. Ker so pomemben razlog opravičil poškodbe in prevelika športna obremenitev nekaterih dijakov športnikov, predlagamo, da bi jih spremljal šolski zdravnik. Frequency and characteristics of excuses given by students attending special sports classes of secondary school to avoid participating in physical education class Objective: The purpose of this research was to establish possible differences between students enrolled in special sports classes and students in regular classes of secondary schools regarding the frequency and characteristics of excuses they give to not participate in physical education lessons. Methods: The used questionnaire examined the frequency of excuses, genuine and invented reasons for excuses, and activities that students participate in while absent from physical education classes. The sample included 560 secondary school students, of whom 210 students in sports classes and 350 students in regular classes. The significance of stratification variables (type of class, year of schooling, gender, overall academic performance), for the explanation of the frequency of giving excuses to not participate in physical education lessons was determined by ordinal regression analysis and logit function. Results: The most significant individual factors determining the frequency of excused absences from physical education lessons are gender and grade level; female students and fourth-grade male students were most likely to use excuses to get out of physical education lessons. The excuse rate was not significantly higher for students attending special sport classes. The median annual absence from physical education for boys and girls in special sports classes is 1 to 5 and 6 to 10 hours, respectively, which is more than for male students and less than for female students attending regular classes. The rate of excused absences from physical education among students in sports classes did not depend on the sports discipline chosen, or the volume of training and performance in the chosen sport, yet was correlated with gender. Male students have a greater odds ratio for frequent excused absences from physical education class. The most frequent reasons for a students coming up with an excuse include injuries, illness and studying. Students in sport classes are more likely than their peers in regular classes to stay in the gym and watch, or study other subjects while not participating in physical education lessons. Conclusion: The system of granting excused absences from lessons is too lenient; moreover, teachers provide no substitute activities for students to participate in while absent from physical education lesson. Since in secondary school students attending sports classes, sports-related injuries and overload constitute an important reason for non-participation in physical education, we suggest that health status of these students should be monitored by a school physician.

The secular trend in the prevalence of overweight and obesity in the population of primary school children from Ljubljana (Slovenia)

Abstract Background: The prevalence of overweight and obesity among children has increased dramatically in recent decades. The survey examined overweight and obesity in the population of boys and girls from Ljubljana, the capital of Slovenia, aged seven through fourteen from 1991 to 2011. Methods: An annually repeated cross-sectional study of data from the national SLOFIT monitoring system was used. The body mass index cut-off points of the International Obesity Task Force were used to identify the prevalence of overweight and obesity. Multinomial logistic regression was used for modelling the probability of overweight and obesity as a function of time (year of measurement), sex and age of subjects. Results: In 1991-2011 period, the odds for overweight and obesity among primary school children (n = 376,719) increased every year by 1.7% (95% CI: 1.6-1.9) and 3.7% (3.4-4%) respectively. Boys have 1.17 (95% CI: 1.15-1.20) times higher odds of becoming overweight and 1.39 (95% CI: 1.35-1.44) times higher odds of becoming obese than girls. In comparison to the reference group (age of 14), the highest odds for overweight were found at the ages of nine and ten (1.39; 95% CI: 1.34-1.44), while for the obesity the highest odds were at the age of eight (2.01; 95% CI: 1.86-2.16). Conclusion: From 1991 to 2011, overweight and obesity clearly became more prevalent in children from Ljubljana. This trend has been more obvious among boys than girls. In comparison to 14-year-old boys and girls, the highest odds for excessive weight were found below the age of 10. Izvleček Izhodišča: V razvitem svetu se zaznava izrazit porast prekomerne prehranjenosti in debelosti med otroki in mladostniki. V raziskavi smo analizirali prekomerno prehranjenost in debelost med ljubljanskimi osnovnošolci, starimi od sedem do štirinajst let, v obdobju po osamosvojitvi Slovenije. Metode: Uporabili smo podatke vsakoletnih meritev telesne višine in telesne mase iz nacionalne zbirke Športnovzgojni karton med letoma 1991 in 2011. V študijo je bila vključena populacija učencev (N=376.719), ki so v opazovanem obdobju obiskovali ljubljanske osnovne šole, njihovi starši pa so pisno soglašali z meritvami. Iz dobljenih podatkov smo izračunali indekse telesne mase, za določitev prekomerne prehranjenosti pa smo uporabili merila Mednarodne delovne skupine za boj proti debelosti. Prevalenco prekomerne prehranjenosti in debelosti glede na spol in starost merjencev ter čas kot kovariato (leta merjenja) smo izračunali z multinominalno logistično regresijo. Rezultati: Vsako leto se ne glede na spol merjencev obet za prekomerno prehranjenost poveča za 1,7% (95% CI: 1,6-1,9%) in za debelost za 3,7% (95% CI: 3,4-4%). Med fanti je obet za prekomerno prehranjenost 1,17-krat (95% CI: 1,15-1,20) in za debelost 1,39-krat (95% CI: 1,35-1,44) večji kot med dekleti. Glede na štirinajstletnike je največji obet za prekomerno prehranjenost opazen med devet- in desetletniki (1,39; 95% CI: 1,34-1,44), za debelost pa med osemletniki (2,01; 95% CI: 1,86-2,16). Zaključki: V obdobju med letoma 1991 in 2011 se je med ljubljanskimi osnovnošolci povečal delež prekomerno prehranjenih in debelih. Prevalenca prekomerne prehranjenosti in debelosti je večja pri fantih kot dekletih, v primerjavi z učenci ob koncu šolanja pa je največja med osmim in desetim letom starosti.

Is the Quality of Judging in Women Artistic Gymnastics Equivalent at Major Competitions of Different Levels

In the present study, the reliability and validity of judging at the European championship in Berlin 2011 were analysed and the results were compared to a different level gymnastic competition - Universiade 2009 in Belgrade. For reliability and consistency assessment, mean absolute judge deviation from final execution score, Cronbach’s alpha coefficient, intra-class correlations (ICC) and Armor’s theta coefficient were calculated. For validity assessment mean deviations of judges’ scores, Kendall’s coefficient of concordance W and ANOVA eta-squared values were used. For Berlin 2011 in general Cronbach’s alpha was above 0.95, minima of item-total correlations were above 0.8, and the ICC of average scores and Armor’s theta were above 0.94. Comparison with Universiade 2009 identified vault and floor scores at both competitions to have inferior reliability indices. At both competitions average deviations of judges from the final E score were close to zero (p=0.84) but Berlin 2011 competition showed a higher number of apparatuses with significant Kendall’s W (5 vs. 2 for Universiade 2009) and higher eta-squared values indicating higher judge panel bias in all-round and apparatus finals. In conclusion, the quality of judging was comparable at examined gymnastics competitions of different levels. Further work must be done to analyse the inferior results at vault and floor apparatuses.

Injuries Among Slovenian Physical Education Teachers: A Cross-Sectional Study

A cross-sectional study was carried out to examine the frequency and types of serious injuries in physical educators throughout their professional career, in relation to their gender, age and teaching level, certain factors causing the injuries and the consequences of those injuries on their working ability. The subjects (n = 468) answered a self-administered questionnaire. In men, one group’s higher frequency of injuries was 1.8 (95% CI [1.26, 2.57]) times higher than in women. Every year in age increased the odds for moving into a group with a higher frequency of injuries by 7.6% (95% CI [1.06, 1.10]). The most common injuries for both genders were lower limb injuries. The most common cause of injury was the teacher’s own mistake. Over 60% of teachers had to modify their teaching after an injury. It is necessary to further explore preventive strategies to reduce injuries in these workers.

Morphological Characteristics and Motor Fitness Among Girls Attending Different Secondary-School Programmes

Durante la adolescencia, se puede observar una baja de interes en la actividad fisica en el tiempo libre de las ninas y el estancamiento en algunos indicadores de la condicion fisica. Se analizo la condicion fisica de una muestra de 14.920 ninas de escuelas secundarias de tres tipos diferentes de programas educativos (academica, tecnica y profesional) con diferentes cantidades de clases de educacion fisica en el curriculum. Se utilizaron los datos del sistema de monitoreo de aptitud fisica de estudiantes de Eslovenia (SLOFIT), incluyendo tres medidas morfologicas y ocho pruebas motoras. Se utilizo un analisis multivariado de varianza para probar las diferencias entre el tipo de programa y la edad de los estudiantes. Las diferencias entre los programas de educacion para todo el conjunto de las variables morfologicas y motoras analizadas no fueron estadisticamente significativas (p <0,001). El programa educativo es un factor mucho mas importante (explica alrededor del 7% de la varianza) que la edad (0,4%). Se explican mejor las diferencias en las variables motoras que las morfologicas. Las ninas del programa academico son mas altas y tienen el pliegue cutaneo del triceps mas delgado. Tambien muestran un mejor estado fisico motor que sus contrapartes de los programas de formacion tecnica y profesional. Sin embargo, no se puede concluir que toda la variabilidad se debe al programa educativo de ensenanza secundaria, ya que los resultados tambien son influenciados por algunos factores personales y sociales que no fueron controlados en nuestro estudio. Sin embargo, es necesario actuar mas para compensar ciertas desigualdades entre las ninas adolescentes, especialmente en las escuelas de formacion profesional.

Impact of prematurity on exercise capacity and agility of children and youth aged 8 to 18

BACKGROUND Preterm (PT) birth and low birth mass (LBW) can impair growth and development of children and may therefore affect their physical performance up to adulthood. AIMS Our aim was to evaluate long-term consequences of prematurity, especially (an)aerobic exercise capacity and agility up to adulthood, by comparing premature and full-term (FT) individuals. STUDY DESIGN, SUBJECTS From 474 subjects born in 1987, who were enrolled into a longitudinal study, 396 (178 PT and 218 FT (with 127 of them LBW)) were followed-up into their early adulthood. Their mass, respiratory status at birth, and results of SLOfit monitoring system (i.e. results of exercise capacity and agility) were monitored on a yearly basis from their age of 8 to 18years. Data were compared statistically with Student t-test or ANOVA. OUTCOME MEASURES, RESULTS PT (or LBW) individuals performed aerobic (time of 600-meter run of females) and the majority of anaerobic tests (sit-ups, standing broad jump, and time of 60-meter run, but not bent arm hang) worse (p<0.05) than FT individuals. Before puberty, however, the agility and fine motor tests (arm plate tapping, polygon backwards, and standing reach touch) were performed better (p<0.05) by PT (or LBW) females, as compared to their FT peers, with no similar results in males. CONCLUSIONS Our results clearly demonstrate that prematurity (especially extreme prematurity) diminishes exercise capacity and agility on the long-term scale, therefore, PT children should be encouraged towards more regular participation in physical activities from early childhood onwards.

Some Indicators of Fatness and Motor Fitness in Slovenian and Serbian Children

El proposito de este estudio fue identificar las diferencias especificas de sexo y edad en la aptitud y niveles de condicion fisica en ninos de dos paises de los Balcanes occidentales en el sudeste de Europa: Eslovenia y Serbia. La muestra consistio en 1.659 sujetos de ambos sexos, con edades entre los 9 y 15 anos. Para el analisis se utilizaron la altura corporal, masa corporal, espesor del pliegue cutaneo del triceps, brazo doblado al colgar y de pie en salto largo. Se utilizo la regresion ordinal para probar las diferencias en el indice de masa corporal (IMC) categorias entre los paises. El analisis MANOVA fue utilizado para probar las diferencias en el nivel de condicion motriz fisica. El conjunto de variables analizadas (p<0,001) entre los paises no fueron estadisticamente significativas. Los ninos y ninas de ambos paises tenian similar altura y masa corporal e IMC, pero en los eslovenos los pliegues cutaneos del triceps mas pequenos. Los ninos de ambos paises fueron superiores en salto largo en comparacion con sus homologos de otras partes de Europa. Sin embargo, los ninos y las ninas eslovenos obtuvieron mejores resultados que los serbios en ambas pruebas de motricidad. Las diferencias en los resultados de las pruebas de motricidad entre los paises fueron mayores a los 9 anos de edad, a los 14 anos se detecto una tendencia aparente: con caracteristicas morfologicas similares, los ninos eslovenos, particularmente las ninas, se encontraban en mejores condiciones fisicas que los ninos serbios. El sexo es el unico parametro significativo (p<0,001) de clasificar en una categoria de IMC. Los ninos tienen una probabilidad promedio aproximada de 1,75 para pasar a una categoria superior IMC tal como las ninas. Entre las ninas, las diferencias entre los paises eran mayores, ya que la prevalencia de las ninas con sobrepeso y obesidad en Eslovenia disminuyen con la edad, mientras que se observo una tendencia inversa en Serbia.