Bojan Leskošek

Exercise-induced changes in iron status and hepcidin response in female runners.

Background and Aims Exercise-induced iron deficiency is a common finding in endurance athletes. It has been suggested recently that hepcidin may be an important mediator in this process. Objective To determine hepcidin levels and markers of iron status during long-term exercise training in female runners with depleted and normal iron stores. Methods Fourteen runners were divided into two groups according to iron status. Blood samples were taken during a period of eight weeks at baseline, after training and after ten days’ recovery phase. Results Of 14 runners, 7 were iron deficient at baseline and 10 after training. Hepcidin was lower at recovery compared with baseline (p<0.05). The mean cell haemoglobin content, haemoglobin content per reticulocyte and total iron binding capacity all decreased, whereas soluble transferrin receptor and hypochromic red cells increased after training and recovery (p<0.05 for all). Conclusion The prevalence of depleted iron stores was 71% at the end of the training phase. Hepcidin and iron stores decreased during long-term running training and did not recover after ten days, regardless of baseline iron status.

Original paper BIAS OF JUDGING IN MEN’S ARTISTIC GYMNASTICS AT THE EUROPEAN CHAMPIONSHIP 2011

The purpose of this study was to establish the validity (unbiasedness) and reliability of E-panel judges officiating execution of exercises in men’s artistic gymnastics at the European Championship 2011 (EC 2011) in Berlin. Overall bias was established in terms of average over-scoring or under-scoring of each judge compared to the final E score of a judges’ E panel. National bias was expressed as average over-scoring of gymnasts of the same nationality as the judge’s. Both types of bias were mostly small (within the +/0.1 point range), but statistically significant and also substantial (over 0.2 point) in some cases. Compared to other competitions, it seems that bias is becoming smaller over time and is also smaller in competitions of higher importance. Analysis of possible consequences of bias showed that overall bias may influence both scores and ranks of competitors, while national bias may be especially problematic in the qualification round, where it may prevent some competitors from qualifying for apparatus finals.

Integrative Examination of Motor Abilities in Dialysis Patients and Selection of Tests for a Standardized Physical Function Assessment

To reduce the need for a large number of executed physical function tests we examined inter‐relations and determined predictive power for daily physical activity of the following tests: 6‐min walk, 10 repetition sit‐to‐stand, time up‐and‐go, Storke balance, handgrip strength, upper limb tapping and sitting forward bend tests. In 90 dialysis and 140 healthy control subjects we found high correlations between all tests, especially those engaging lower extremities. Sit‐to‐stand, forward bend and handgrip strength were selected for the test battery and composite motor performance score. Sit‐to‐stand test was superior in terms of sensitivity to uremia effects and association with daily physical function in adjusted analyses. There was no incremental value in calculating the composite performance score. We propose to standardize the physical function assessment of dialysis patients for cross‐sectional and longitudinal observations with three simple, cheap, well‐accessible and easily performed test tools: sit‐to‐stand test, handgrip strength and Human Activity Profile questionnaire.

Six-Minute Walk Test in Renal Failure Patients: Representative Results, Performance Analysis and Perceived Dyspnea Predictors.

Objectives Six-minute walk test in dialysis population hasn’t been consistently evaluated for the isolated impact of renal failure and other predictive factors. We measured six-minute walk distance in patients representative for low level of comorbidity and searched for potentially modifiable predictive factors of performance and dyspnea. Methods This was a cross-sectional study with hemodialysis patients (N = 90) and control subjects (N = 140). Main outcome measures: six-minute walk test distance and dyspnea severity using the 10-item Borg scale. Results Median distance decreased from 600m below the 6th decade to 420m in the 8th decade of age. Dialysis dependence predicted 101.5m shorter distance in the adjusted model that explained 70% of variability in results. Adjusted for significant covariates of age, height and spontaneous gait speed, fat mass (but not lean body mass) and serum total iron binding capacity were significantly associated with distance (95% CI for B coefficients -4.6 to –1.4 m/kg and 0.1 to 5 m/μmol/l, respectively). Serum total iron binding capacity as an explanatory variable was superior to C-reactive protein and albumin. Dialysis dependence, odds ratio (OR) 2.97 (1.11–7.94), spontaneous gait speed, OR 0.08 (0.02–0.41), rate-pressure product, OR 1.15 (1.08–1.23) and hemoglobin, OR 0.95 (0.92–0.98) predicted dyspnea in the adjusted model. Conclusions Renal failure without the confounding effect of comorbidity is a significant negative predictor of performance at six-minute walk test and perceived level of dyspnea. Body fat mass and serum total iron binding capacity are the main potentially modifiable predictors of performance, total iron binding capacity being superior to C-reactive protein and albumin. Although hemoglobin is not associated with test performance, it negatively predicts perceived shortness of breath.

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.

Split-Step Timing of Professional and Junior Tennis Players

Abstract The purpose of the study was to determine the timing of a split-step in three categories of tennis players in four groups of strokes. Subjects were divided into three groups: male and female junior, and male professional tennis players. During two tournaments, all matches were recorded with two fixed video cameras. For every stroke, the timing of the split-step between the opponent’s impact point when hitting the ball and the player’s split-step was measured. A two-way analysis of variance (ANOVA) was used to determine the differences between groups of strokes, players and the interaction Player x Stroke Group. A Tukey post-hoc test was employed to determine specific differences. The results revealed differences between players in detecting the opponent’s movement, stroke and ball flight, which were reflected in different split-step timings. Each tennis player has his/her own timing mechanism which they adapt to various game situations. Response times differ significantly depending on the game situation. On average, they are the lowest in the serve, and then gradually rise from the return of the serve to baseline game, reaching the highest values in specific game situations. Players react faster in the first serve than in the second one and in the return of the serve, the response times are lower after the return of the second serve

Correlation of sports activity with stress and satisfaction with life among adult Slovenians

Izvleček Izhodišča: Namen raziskave je bil ugotoviti povezanost med športno dejavnostjo (ŠD) in doživljanjem stresa ter vrednotenjem zadovoljstva z življenjem odraslih Slovencev. Metode: Podatki so bili pridobljeni s pomočjo anketnega vprašalnika na reprezentativnem vzorcu 856 odraslih Slovencev in Slovenk (povprečne starosti 39 ± 13,7 leta). ŠD je bila opredeljena s številom dni ukvarjanja s katero koli športno dejavnostjo tedensko. Stres je bil opredeljen s pogostostjo doživljanja devetih znakov stresa na štiristopenjski lestvici. Pri oceni zadovoljstva z življenjem so udeleženci raziskave izrazili strinjanje oziroma nestrinjanje s petimi postavkami na petstopenjski lestvici. Vrednosti prve glavne komponente stresa in lestvice zadovoljstva z življenjem je bila določena z Anderson-Rubinovo metodo. Povezanost spremenljivk je bila ocenjena s Spearmanovim koeficientom korelacije in s splošnimi linearnimi modeli. Rezultati: ŠD je bila statistično značilno povezana s stresom (p = ,03) in z zadovoljstvom z življenjem (p < ,01). V linearnih modelih imajo izbrani dejavniki (ŠD, starost, spol in izobrazba) skupaj statistično značilen vpliv (pri stresu: R2 = ,040; p < ,001; pri zadovoljstvu: R2 = ,068; p < ,001); ŠD ima statistično značilen vpliv le na oceno zadovoljstva z življenjem (η2part.= ,020; p = ,002). Na stres statistično značilno vplivajo vsi preostali dejavniki, na zadovoljstvo z življenjem pa le izobrazba. Zaključki: Na podlagi dobljenih rezultatov lahko sklepamo, da so športno dejavnejši odrasli Slovenci manj pod stresom in bolj zadovoljni s svojim življenjem, vendar je ta vpliv ob upoštevanju vpliva starosti, spola in izobrazbe razmeroma majhen. Abstract Objective: The aim of the study was to investigate the correlation of sports activity (SA) with stress experience and evaluation of satisfaction with life among adult Slovenians. Methods: Data was collected with a survey on a representative sample of 856 adult Slovenians (average age 39±13.73 years). We determined sports activity with incidence of any sports activity - times per week. To determine mental health, the respondents marked how often the 9 signs of stress appeared within a last month and how satisfied they were with their life. Scores on the first component of stress and satisfaction with life scale were computed using Anderson-Rubin method. The correlations between variables were evaluated using the Spearman correlation coefficient and general linear models. Results: SA is statistically significantly correlated with stress (p= .03) and satisfaction with life (p= .00). In the models for prediction of stress and satisfaction with life, the set of predictors (SA, age, gender and education) has a significant effect (R2= .040, p< .001; R2= .068, p< .001), with SA having a statistically significant effect only on value of life satisfaction (η2part = .020, p= .002). A set of all mentioned predictors has significant effect on stress, while only education beside SA has a statistically significant effect on satisfaction with life. Conclusions: It could be concluded that individuals that are more active in sports experience the signs of stress less often and that they are more satisfied with their lives, but taking age, gender and education into consideration, SA is not the main predictor.

Reliability and validity of judging in women's artistic gymnastics at University Games 2009

Abstract The aim of our research was to analyse the reliability and validity of judging on all womens apparatuses and all sessions (qualification, all round finals and apparatus finals) at the World University Games-Universiade 2009 in Belgrade. For validity assessment, mean absolute and rank deviations of judges’ execution scores were calculated. For consistency and reliability assessment, Cronbachs alpha coefficient, intra-class correlations, Armors theta and Kendalls W coefficient were calculated. Vault and floor exercise finals were the sessions with the highest scores and the lowest score dispersion. The overall highest individual judge average absolute deviation was 0.34 point and the largest mean rank deviation was 0.88 with most values well below this. A correlation matrix for between-judge correlations identified three judges (out of 20) in the apparatus finals sessions with remarkably inferior correlations with others. Except for vault and floor finals, the results in terms of consistency (Cronbachs alpha mostly above 0.95) and reliability (Armors theta mostly above 0.94, intra-class correlation for single and average measures above 0.87 and 0.94, respectively) were satisfactory. In conclusion, overall high values of reliability and consistency indices were found. Sessions where the variability between competitors is low (such as vault and floor finals in this competition) should be inspected with special care in future judging analyses.