Background: The aim of the present randomized, crossover study was to determine the physiological and cognitive function responses while wearing a facemask during a maximal running aerobic fitness test. Methods: Fourteen healthy, nonsmoking physical education students (age = 17.5 years, height = 1.72 m, body mass = 70.4 kg) volunteered to participate in this study. They carried out a 20 m multistage fitness test (MSFT) while wearing or not a cloth facemask on two separate occasions performed in random order. The “Rating of Perceived Exertion” (RPE) and the d2 test for visual attention were administered and assessed before and immediately after the MSFT for both conditions (with or without a facemask). Results: When wearing the facemask, the participants exhibited lower maximal aerobic speed (p = 0.039), VO2max (p = 0.039), distance covered during the MSFT (p = 0.057), and concentration performance (p < 0.001), when compared with the control situation (without facemask). Moreover, they made more errors compared with the control condition (p = 0.021). The use of a cloth facemask during maximal endurance running tests (such as the MSFT) reduced VO2max, and measures of cognitive performance as assessed by the test of focused visual attention (the d2 test). This data suggests avoiding using a cloth facemask during maximal aerobic fitness tests, and before any tasks that require a high level of visual attention.

Abstract Objectives: This study evaluates the effect of post-activation potentiation (PAP) after 5x5s maximal voluntary isometric contractions (activation stimulus, AS) on tensiomyography (TMG) and torque twitch contractile parameters of vastus lateralis (VL) and medialis (VM), respectively. Further, we validated the decomposition of TMG response to separate responses of three fiber types. Methods: 15 healthy individuals participated in this study (40% women; age 19±2.3 years). A decomposition of VL TMG response was done after optimal fitting of three exponential curves. Results: We found main effects in contraction time (Tc) for muscle, method and time. Furthermore, we found interactions between muscle*method, method*time and muscle*method*time. Compared to PRE AS, we found shorter TMG Tc in VL and VM during the first two minutes after AS. Torque Tc remained unchanged in VL, while it increased in VM within 30 seconds after AS. A decomposition of VL TMG response confirmed PAP effects being present only in decomposed type IIb muscle fibers. Conclusion: The TMG is a sensitive method to detect PAP effects with a sensor mounted directly above the muscle belly. After the decomposition of the TMG signal to three separate muscle fiber phenotypes, we provided a non-invasive insight in the contribution of each muscle fiber phenotype to the PAP of the whole muscle.

Abstract Objective: The present study aimed to: i) determine the contractile properties of the major lower limb muscles in female soccer players using tensiomyography; ii) investigate inter-limb differences; and iii) compare inter-limb differences between different selections and playing positions. Methods: A total of 52 female soccer players (A team; U19 and U17) were recruited. The vastus lateralis (VL), vastus medialis (VM), rectus femoris (RF), biceps femoris (BF), gastrocnemius medialis (GM), lateralis (GL) and tibialis anterior (TA) of both lower limbs were evaluated. Results: When the entire sample was assessed regardless of selection or playing position, there were significant inter-limb differences in all measured muscles except BF. Compared to the non-dominant limb, the dominant limb had higher delay time in VL (p=0.008), while showing lower values in VM (p=0.023), GL (p=0.043) and GM (p=0.006). Contraction time was lower in the RF of the dominant limb (p=0.005) and VM (p=0.047), while showing higher values in VL (p=0.036) and TA (p<0.001) as compared to the non-dominant limb. Conclusion: Given the differences found between the limbs in the whole sample studied, it is necessary to examine both limbs to gather a more in-depth understanding of underlying mechanisms related to neuromuscular functions in female soccer players. Level of evidence: Prognostic study, Level II.

The aim of the present study was to investigate whether the physiological parameters indicative of cardiorespiratory fitness obtained during the 30-15 intermittent fitness (30-15IFT) test and the multistage laboratory treadmill endurance (TR) test differ. Nineteen elite handball players were recruited for the current study and assigned in a cross-over manner to one of two tests to be performed 48 h apart at each visit to the testing facility. The results showed that VO2max (percentage difference [PC] = 6.1%; p = 0.004) and maximal running velocity (V) (PC = 19.4%; p < 0.001) were significantly higher for the 30-15IFT test than that obtained during the TR test. Furthermore, the onset of blood lactate accumulation was shown to be significantly higher for all measures considered to predict it during 30-15IFT compared to TR as follows: VO2max (PC = 12.6%; p = 0.001), running speed (PC = 33.9%; p < 0.001), and maximal heart rate (PC = 7.5%; p < 0.001). The current study highlights the importance of sport-specific testing, particularly for measuring individual cardiorespiratory fitness in elite handball players, as TR may underestimate crucial variables used for both diagnostics and training prescription.

High relationships between muscle strength and various forms of jumps are usually based on the research samples of professional athletes or students of sports and physical education. However such studies are less known in the case of recreational women. This study aimed to determine the relationship between isokinetic parameters of knee joint muscle strength with the efficiency of performing vertical jumps. The sample represents a group of 16 healthy and physically active women (age=31.04±3.71; height 168.13±8.34; weight 59.80±9.80). Knee extensors and flexors were evaluated by using an isokinetic dynamometer, while the two-foot vertical jump performance was measured using the Opto Jump System. Pearson's correlation coefficient was used to determine correlation magnitude (p<.05). The obtained results indicated high correlations of the knee extension peak torque dominant leg (KEPT D), knee extension peak torque non-dominant leg (KEPT ND) and knee flexion peak torque non-dominant leg (KFPT ND) with counter movement jump free arms (CMJFA) (r=.525; r=.511; r=.594; p<.05). High correlations was also indicated between KFPT ND with counter movement jump (CMJ) (r=.514; p<.05). Given that these are recreational women, we can assume that the countermovement free arm jump type was the most natural form of expressing their explosive potential. It is certainly important that future studies further examine the relationships between muscle strength and performance of primary and specific motor tasks in recreational women.

We aimed to investigate whether the addition of whole-body vibration (WBV) to resistance training (RT) will be more beneficial in improving lower limbs muscle strength, power and sprinting performance than RT alone in young basketball players. We recruited 30 young basketball players to participate in four weeks of training and assessments. They were randomized into the WBV resistance training group (VRTG, n=15) and a conventional resistance training group (RTG, n=15), performed 3 times per week. At the beginning and end of the four weeks a back squat one-repetition maximum (1RMBS), Countermovement jump (CMJ), Squat jump (SJ), 10 meters (10m) and 20 meters sprint (20m) were performed. We found that: a) VRTG when added to RT can induce greater improvements in 1RMBS (percentage difference [PD], 8.4%, p < 0.001), CMJ (PD = 4.7%, p = 0.001) and SJ (PD = 1.6, p = 0.02) than RT alone. In contrary, significant time*group interactions were found for sprint times at 10m (p=0.08, F=3.2) and 20m (p=0.17, F=1.93). An additional 4-week WBV resistance training program proved effective in improving lower limb power and strength in young basketball players. When performed on a vibration platform (with accurate and constant vibration stimulus parameters), the resistance exercises were superior to their conventional forms and resulted in additional gains on measures of muscle power and strength, while sprint performance remained unchanged.

This study aimed to examine the relation between agility, sprint ability, and vertical jump performance of young basketball players. Fifty (n=50) young basketball players (mean±SD: age = 12.63±0.95; height = 160.84±6.31 cm; body mass = 50.82±6.88 kg) participated in the study. The agility T-test and 505 test were assessed to determine agility, 10m and 20m sprint was measured to determine sprint ability and countermovement jump (CMJ) for jumping performance. The results of Pearson’s Product Moment Correlation analysis indicated large to very large relation between agility tests and sprint performance (r = 0.61 to 0.85); agility and jump performance (r = - 0.64 to - 0.67); sprint and jumping performance (r = -0.59 to -0.77). The results of the study suggest that agility, sprint, and jumping performance share common physical demands, therefore it is necessary to develop them during the training.

Considering the growing global problem and the lack of obesity data in Bosnia and Herzegovina (BH) the main aim of this paper was to determine BH school-age children body composition and determine the differences in body composition between girls and boys classified in underweight, normal weight and overweight according to the body mass index (BMI) score. 2524 participants 1763 girls and 761 boys (aged 10-13 yrs.) from 32 elementary schools were randomly selected and divided to 3 BMI groups by WHO cut-off points. InBody 370 Body Composition Analyzer (BioSpace, Seoul, Korea), a segmental bioelectrical impedance analysis (BIA) device was used to gather data. The results showed ~38% of the sample were classified as overweight whilst gender differences showed higher body fat mass and fat percentages in arms, trunk and legs in underweight and normal weight girls and higher skeletal muscle mass in normal weight and overweight boys.

The purpose of this study was to evaluate the relationship between knee extensor and flexor muscles strength and vertical jump in professional female volleyball players. Forty-one female volleyball players participated in this study. Isokinetic PT and was measured at 60°/s, whilst CMJ performance using a force plate. The participants were later divided to WG (weaker group - PT/BW<2) and SG (stronger group - PT/BW>2). Isokinetic concentric knee extension and flexion PT was significantly correlated with CMJ performance. However, higher correlation coefficients were obtained at the non-dominant leg. No significant differences were found but mere trend favoring non-dominant leg muscles in the weaker group. Strong positive correlation exists between isokinetic knee PT and CMJ height in professional female volleyball players. When divided and compared to WG and SG the results indicate weaker players tend to modify their technique individually and towards unilaterality as so they could maximize their performance.

Mensur Vrcić , Ratko Pavlović , Sid Solaković, Erol Kovačević 1 and Ensar Abazović Faculty of Sports and Physical Education, University of Sarajevo, Bosnia and Herzegovina Faculty of Physical Education and Sports, University of East Sarajevo, Bosnia and Herzegovina 3 Clinic for Vascular Surgery, Clinical Center in Sarajevo, Bosnia and Herzegovina 4 Faculty of Kinesiology, University of Split, Croatia