This study examines the differences in the anthropometric characteristics and motor abilities of young elite female volleyball players depending on their playing position. This study was conducted with 114 U17 female players of the Serbian national team (age: 15.4 ± 0.4 years; body mass: 65.8 ± 7.8 kg; height: 176.8 ± 7.7 cm). All participants had at least four years of volleyball experience. A one-way ANOVA revealed significant differences (p ≤ 0.05) in body mass (BM), body height (BH), body mass index (BMI), one-arm standing reach (1ARS), two-arm standing reach (2ARS), arm span, a medicine ball throw (MT), standing long jump (SLJ), squat jump (SJ), countermovement jump without an arm swing (CMJ), 5 m sprint (S5), 15 m sprint with a flying start (S15), 20 m sprint (S20), and t-test (TT). The results show that a player’s position significantly impacts their anthropometric characteristics and motor abilities, with liberos requiring agility and flexibility, while middle blockers and opposite hitters focus on strength and explosiveness. Outside hitters and setters achieved high results in jump tests, while outside hitters, although agile, had slightly lower results in the long jump. The results confirm that BH and BM, 1ARS, 2ARS, arm span, explosive power, agility, speed, and flexibility significantly impact performance, indicating that a player’s position affects their anthropometric characteristics and motor abilities.

The aim of this study was to determine the sensitivity of different methods of partialization, in terms of different body component indices in relation to indicators of strength and explosiveness. The research involved 187 subjects who were divided into two groups based on sex. This research consisted of measuring body composition characteristics by multichannel bioimpedance analysis (BIA) InBody 720, as well as contractile characteristics of different muscle groups with tenziometric Dinamometry method. Based on the results of the factor analysis we found that regardless of the sex the most sensitive variable for partialization of absolute body isometric strength variable (ABiS) is partialization by allometric scaling (0.964 for females and 0.947 for males explained factor variance). However, in the case of absolute body isometric explosiveness (ABiE), the results of this study have demonstrated that partialization relative to skeletal muscle mass according to the body longitudinality - skeletal muscle mass index (SMMI) is the methodological choice disregarding the sex (0.982 for females and 0.980 for males explained factor variance). The results of the study have shown that for the purpose of scaling the maximal strength relative to body composition, the allometric method can be considered as a choice, while for the partialization of maximal isometric explosiveness skeletal muscle mass index is the best choice insensitive of the sex.

The aim of this study was to investigate how lifting straps affect isometric back extensors muscle strength. The participants were divided according to gender and training level: trained – powerlifters (n = 17) and control – a specifically non-trained group (n = 24). For the purposes of this study, the maximum voluntary contraction of the back extensors was measured in isometric conditions in the isometric back extension exercise. After a 5-minute standard and specific warm-up, the participants had three trials each with lifting straps and without lifting straps, with a break of 2 minutes between trials. They were given the verbal instruction "pull as hard and fast as possible” and hold for 2 to 3 seconds. Repeated measures ANOVA showed a general statistically significant difference (p<0.05) between testing procedures (classical and straps). A paired samples t-test was used to determine differences between maximal and explosive strength variables. Then, the percentage difference (Δ) of all variables (Fmax - maximal force, RFDmax - maximal rate of force development, tFmax - time needed to reach maximal force, tRFDmax - time for maximal rate of force development) was calculated using the formula: Fmax_Δ = ((Fmax_straps - Fmax_class) / Fmax_class) *100. Differences in the maximum isometric back extension force (Fmax) were found in both groups (powerlifter males - p = 0.004, females - p = 0.019 and control group males - p = 0.018, females – p = 0.001), while differences in tFmax were observed only in the control group (males – p = 0.001 and females - p = 0.000). The results showed that lifting straps have a positive effect in measuring supra-maximal isometric strength (averaged enhancement was 15.93±4.58% regardless of gender and training status), and can potentially be used in a methodological sense to determine the objective values of the biological contractile potential in terms of maximum strength, in pulling type of exercises that include a hand grip (the deadlift, lat pull down, mid-thigh pull test).

This study aimed to investigate the morphological characteristics of male and female students at the Academy for National Security. The sample consisted of 54 healthy first and second-year students, including 41 males (age: 19.83 ± 0.74 yrs.; body height: 181.01 ± 7.26 cm; body mass: 76.77 ± 8.90 kg) and 12 females (age: 19.62 ± 0.65 yrs., body height: 169.72 ± 4.20 cm; body mass: 68.65 ± 8.91 kg). All measurements were performed during the academic year 2023-2024 at the Methodological Research Laboratory (MIL) at the Faculty of Physical Education and Sport, University of Belgrade. The measurement of body composition was carried out using multisegmental bioelectrical impedance, using the device: "InBody 720". Six body composition variables were analyzed: Body Mass Index (BMI), Percent of Body Fat Mass (PBF), Percent of Skeletal Muscle Mass (PSMM), Skeletal Muscle Mass Index (SMMI), Fat Mass index (FMI) and Protein Fat Index (PFI). The values obtained for all variables were processed using basic descriptive statistics. The results showed that the mean BMI of male and female students was 23.41 ± 2.21 kg·m-2 and 23.82 ± 2.89 kg·m-2, PBF was 13.32 ± 4.06 % and 29.94 ± 5.02 %, PSMM was 49.38 ± 2.91 % and 38.72 ± 2.98 %, SMMI was 11.53 ± 1.00 kg·m-2 and 9.17 ± 0.84 kg·m-2, FMI was 3.15 kg·m-2and 7.24 kg·m-2, PFI was 1.51 ± 0.73 and 0.48 ± 0.12. Based on the results, it can be concluded that the current morphological status of students at the Academy for National Security falls within the category of the population with average anthropometric and morphological status of students at the University of Belgrade, with females having a higher percentage of body fat, exceeding the biological maximum for females.

The aim of this study is to determine the metric stability of the one-month handgrip test (HGT) in order to define the contractile characteristics of the biological variation of maximal isometric strength (F _max) and maximal isometric rate of force development (RFD _max) of the handgrip in two different testing regimes (classic and impulse). The study was conducted with a total of 16 participants (11 men and 5 women). Testing was performed using an isometric handgrip probe with a standardized test protocol and equipment sports medical solutions (SMS). The results of F _max showed a low relative standard error of the mean (RS = 1.33 %), a high value of inter-class correlation (ICC = 0.996), and no statistically significant change in trend (p > 0.05) during the testing period. Therefore, can conclude that the HGT procedure in classic mode can be used as a stable parameter in a human subject sample. However, the RFD _max results showed a low RS (2.13 %) and a high ICC value (0.996), but a statistically significant change of trend (p < 0.05) during the measurement period. The regression constant (RCO) trend was 42.629 N/s, which can be attributed to learning or to the adaptive effects of the test procedure, which triggered similar adaptation processes as the training. In general, it can be concluded that the handgrip can be used to sensitively measure the effects of different long-term health improvements, or the effects of different medical/health exercises, rehabilitation programs, effects of medication applications, or dietary supplements for F _max. However, further research should be conducted for the RFD _max considering the metric stability parameters.