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We examined the relationships between heights of different vertical jumps and isometric single-joint strength characteristics of ankle, knee, hip, and trunk joints in young male soccer players (n = 117). The highest peak torque and rate of torque development (RTD) outcomes were in low to moderate correlation with jump heights (r = 0.25-0.50). The correlations were generally higher for bilateral than unilateral jumps. Linear regression models accounted for 33-35% and 24.5 of the variance in bilateral and unilateral jump height, respectively. Hip extension peak torque, ankle RTD and trunk lateral flexion peak torque were most consistently included in the regression models. Our results suggest the that single-joint isometric testing does not seem to be useful to detect weaknesses related to vertical jump performance. The relative importance of individual lower limb joints for vertical jumping seems comparable. Trunk strength should not be neglected as the determinant of jumping performance.

Time spent in physical activity, sedentary behavior, and sleep collectively impact health of older adults. There is a need for valid self-reported methods for the assessment of movement behaviors across the entire 24-hr day. The aim of this study was to explore the validity of the German version of Daily Activity Behaviours Questionnaire (DABQ), the "Schlaf- und Aktivitätsfragebogen (SAF)," among older adults. Participants were asked to wear activity monitor (activPAL) for a period of 8 days and to complete the German version of DABQ. Seventy-seven participants (45 females; 68 ± 5 years of age) completed the protocol. Spearman's correlation coefficients between DABQ and activPAL estimates for time spent in sleep, sedentary behavior, light physical activity, and moderate to vigorous physical activity were.69,.35,.24, and.52, respectively. The German version of the DABQ showed satisfactory validity to be used in epidemiological research and population surveillance among older adults. [ABSTRACT FROM AUTHOR]

Copyright of Revija Šport is the property of Sport: Revija Za Teoreticna in Praticna Vprasanja Sporta and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revija Šport is the property of Sport: Revija Za Teoreticna in Praticna Vprasanja Sporta and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revija Šport is the property of Sport: Revija Za Teoreticna in Praticna Vprasanja Sporta and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Students spend a considerable amount of time in school. This study aimed to determine the prevalence of musculoskeletal pain and the association between the pain and suitability of school furniture and daily activities among primary school and university students. A total of 238 primary and university students participated in the study. The adapted Nordic questionnaire was used to assess pain prevalence, the BackPEI questionnaire was used to assess school-related factors, and student furniture mismatch calculations were performed to determine the anthropometric suitability of school furniture. Most students did not have a proper body posture while sitting, did not lift objects properly, and used TV and computer frequently. A high student-furniture mismatch was found for seat and desk height. The neck, lower back, shoulders, and upper back were the most affected body parts. Our study confirmed that musculoskeletal pain occurs in primary school students and increases with age, especially lower back pain. Proper backpack wearing was found to be an important factor in alleviating neck pain. Students who sat or lifted objects properly were more likely to report upper back pain, and students whose backrest height was appropriate were more likely to report lower back pain. Further efforts should be made to establish a comparable study protocol using objective methods to obtain more valid and reliable data to study school-related risk factors for musculoskeletal pain in students using prospective study protocols. [ABSTRACT FROM AUTHOR]

The purpose of this study was to assess the association between bilateral deficit (BLD) in countermovement jump and change of direction (CoD) performance. Therefore, 165 young basketball players (60 females) and 95 young tennis players (39 females) performed two different CoD tasks (90° and 180° turns) and bilateral and unilateral countermovement jumps. BLD was calculated based on jump height, peak power and several phase-specific force impulses (FI). For male athletes, several statistically significant small to moderate associations were found between the CoD performance and BLD (r = 0.21–0.52). While the BLD in the propulsive phase FI seems to be most consistently associated with CoD performance, all associations were weak (r = 0.21–0.28 in basketball, 0.28–0.36 in tennis). Associations between BLD in total positive (braking and propulsive phase) FI and CoD performance were moderate (r = 0.45–0.52) in male tennis players. For female athletes, the associations were even smaller and almost exclusively statistically non-significant. Although indirectly, our results imply that resistance training based on unilateral exercises could be useful to improve CoD performance. It has to be stressed that further training studies are needed to directly confirm this assumption. [ABSTRACT FROM AUTHOR]

Self-reports are commonly used tools for obtaining sedentary behaviors. The aim of our study was to assess agreement between two self-reports of sedentary time and a gold standard sedentary time objective monitor. A worksite sample (n = 42) completed the Slovenian version of the Global Physical Activity Questionnaire (GPAQ), the Slovenian version of the Sedentary Behaviour Questionnaire (SBQ for weekdays) and wore an objective physical activity monitor (activPAL) for up to five consecutive working days. Results revealed that GPAQ and SBQ consistently underestimated the total sedentary time, with the mean bias of -165 min/day and -181 min/day, respectably. Wide limits of agreement showed poor precision and intraclass correlation revealed a low level of agreement. GPAQ and SBQ are not recommended to be used in studies seeking for relationships with health outcomes, nor in studies where detecting the behavioral change is of interest. Objective measurement should be the preferred choice when possible.

Introduction: The aim of this study was to assess the validity and reliability of a hydraulic resistance device (HRD) for monitoring sprint split times under different loads within and between sessions. Methods: Three 20-m sprints with low (15 N), medium-low (40 N), medium-high (50 N), and high (130 N) HRD resistance levels (loads) were performed on two separate occasions 14 days apart. Twenty-four student athletes (24.8 ± 3.8 years) participated in the first session and 13 (24.1 ± 3.2 years) of them in the second session. Resisted sprints split times over a distance of 0-20 m (t0-5, t0-10, t0-20, t5-10, t10-15, t15-20) were measured simultaneously with magnetic incremental encoder embedded in the HRD and a system of single-beam timing gates. Results: The results showed acceptable to high within session (ICC3,1 = 0.91-0.99; CV = 0.92%-3.38%) and between session (ICC3,1 = 0.82-0.99; CV = 1.62%-4.84%) reliability of HRD for measuring all split times at all loads. The minimal detectable change between sessions ranged from 3.3% at high load to 9.9% at low load. The HRD systematically underestimated timing gates times at all loads (bias = 2.01-11.08%), yet good to excellent consistency was observed between the HRD and timing gates, specifically for t0-10 and t0-20 (ICC3,k lower 95% CI = 0.84-0.99). Discussion: Due to high reliability and good validity in monitoring resisted sprint times, the HRD holds potential for practical and research applications. [ABSTRACT FROM AUTHOR]

Featured Application: Rate of Torque Development Scaling Factor (RTD-SF) is sensitive enough to detect changes following training programs based on electrostimulation or voluntary contractions. This study explored the changes in the rate of torque development scaling factor (RTD-SF) and maximum voluntary isometric contraction (MVC) variables following six weeks of unilateral isometric electromyostimulation (EMS) and voluntary (VOL) exercises. Twenty-six physically active participants were randomly assigned to EMS (n = 13) or a VOL group. MVC and RTD-SF of the quadriceps femoris of both legs were assessed before and after training. EMS and VOL exercises had identical frequency (three sessions/week), intensity (60% MVC), volume (40 contractions), and work-to-rest ratio (18 min: 6.25 s of work/20 s of rest). There were no between-group differences for the trained leg with overall increases in maximal torque (Tmax) of ~29% (d = 2.11–2.12), ~13% for RTDmax (d = 0.92–1.10); ~23% for Intercept (d = 0.72–0.78), and reduction in RTD-SF by ~15% (d = 1.01–1.10). In the non-trained leg, significant moderate change was only observed after EMS for RTD-SF which decreased by 12.5% (d = 0.76). Both EMS and VOL training applied at equivalent workloads positively impact on Tmax, RTDmax, and Intercept, but they negatively affect the quickness with which muscle contracts across a wide range of submaximal forces. Using a moderate training intensity in regularly physically active participants could explain the absence of cross-education in the VOL group. [ABSTRACT FROM AUTHOR]

The objectives of our study were 1) to examine whether the force-velocity-power (FvP) outcomes in the concentric and eccentric phases of flywheel (FW) squats differ among sports disciplines and 2) to investigate the association between FvP outcome variables and two key sport-performance indicators: countermovement jump height (CMJ) and change of direction (CoD) time involving 90° or 180° turns. Tests were performed by 469 athletes from five different sport disciplines and physical education students. Our results showed that FvP outcomes, when measured during the eccentric phase of the FW squat, effectively differed between athletes from different sports. However, during the concentric phase of the squat, only for the slope variable differences between sports were found. Contrary to our hypothesis, there were no statistically significant correlations between FW squat FvP outcomes and CMJ or CoD test results. These results suggest that FvP outcomes derived from FW squats may lack external validity and cannot be reliably used as a predictor of athletes' jumping and agility performance. The paper discusses possible reasons for the larger differences between sports in eccentric FvP outcomes, as well as the absence of correlations between FvP outcomes and functional tests. [ABSTRACT FROM AUTHOR]

This study investigated the reliability and validity of linear sprint tests (LS) and curvilinear sprint tests (CS) using a GPS device (GPEXE lt). Twenty-one (21) student athletes completed a 40 m LS as well as a left and right CS. Maximum sprint speed (MSS) and split times at short (0–10 m), intermediate (0–20 m), and long (0–30 m) distances were determined using the GPEXE lt and single-beam timing gates (TG). Intrasession reliability and concurrent validity of GPEXE lt were assessed. The GPEXE lt consistently showed high reliability for MSS (ICC ≥ 0.95; CV ≤ 1.8%), despite underestimation compared to TG (bias = −2.57 to −0.95%; ICC ≥ 0.87). Acceptable reliability was observed for CS and LS intermediate and long distance split times (ICC ≥ 0.91; CV ≤ 2.1%), with lower reliability for short distances (ICC ≥ 0.70; CV ≤ 3.6%). The GPEXE lt split times for CS and LS showed good agreement with TG (ICC ≥ 0.66), but were overestimated at long distances (5.5–9.7%) and short distances (11.1–14.6%). Although the MSS was found to be the most reliable and valid variable to assess LS and CS speed performance with GPEXE lt, caution is needed due to limited validity. [ABSTRACT FROM AUTHOR]

Peripheral magnetic stimulation has recently been introduced as a non-invasive but effective physical agent to improve muscle strength and everyday function. The aim of this study was to evaluate the feasibility and safety of an exercise program focusing on the abdominal muscles in combination with the peripheral magnetic stimulation of the abdominal muscles. Male and female overweight and obese adults (n = 19) participated in an eight-week exercise program with the additional peripheral magnetic stimulation of the abdominal muscles. Outcome measures included changes in abdominal subcutaneous fat thickness, trunk muscle strength, body composition, and self-reported body satisfaction. Subcutaneous fat thickness was significantly reduced after the intervention (p < 0.01–p < 0.001). Trunk flexion and left side flexion strength increased significantly after the intervention, although no significant changes were observed for trunk extension (p = 0.07) and right side flexion strength (p = 0.13). The body satisfaction self-assessment score significantly increased (p < 0.01), while body mass, body mass index, and fat mass significantly decreased after the intervention (p < 0.05). Our findings suggest that an exercise program with the additional peripheral magnetic stimulation is feasible and safe for overweight and obese participants. These results support the use of peripheral magnetic stimulation as a safe adjunct to the voluntary abdominal muscle contraction. Future studies are needed to evaluate the efficacy of the additional peripheral magnetic stimulation of the abdominal muscles compared to the voluntary contraction of the abdominal muscles alone. [ABSTRACT FROM AUTHOR]

Studies indicate that natural wooden materials positively affect students' well-being in classrooms. In addition, students spend a considerable amount of their time in classrooms predominantly seated, making school interiors a suitable place to reduce sedentary behaviors of children. A mixed team of experts in human factors, architecture, design and engineering designed a prototype wooden standing desk for indoor use and formed focus groups with students and teachers to gather feedback on the development process and to evaluate the suitability of the prototype. The prototype desk was well received by the primary school teachers and students. The students appreciated plywood as the main material for the construction of the desk; however, they criticized that the wooden tabletop should be more resistant. The height adjustability of the desk and the tiltable tabletop were the most appreciated features of the prototype. Further studies should be conducted to investigate the optimal material, shape and color of the school desk, especially the tabletop, and additional efforts should be made to design furniture that promotes a less sedentary classroom and improves students' well-being at school. [ABSTRACT FROM AUTHOR]

Copyright of Revija Šport is the property of Sport: Revija Za Teoreticna in Praticna Vprasanja Sporta and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revija Šport is the property of Sport: Revija Za Teoreticna in Praticna Vprasanja Sporta and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revija Šport is the property of Sport: Revija Za Teoreticna in Praticna Vprasanja Sporta and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revija Šport is the property of Sport: Revija Za Teoreticna in Praticna Vprasanja Sporta and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Strength and conditioning experts widely recognize the dynamic strength index (DSI) as a tool for assessing an athlete's ability to utilize strength in dynamic actions. The DSI is calculated as the ratio of peak force in dynamic actions versus isometric ones. To date, the influence of fatigue on the DSI is still not fully understood. This study aimed to explore the effects of both dynamic and isometric fatigue tasks on the DSI. Methods: A total of 24 physically active participants underwent fatigue tests involving repeated countermovement jumps (dynamic) and repeated isometric mid-thigh pulls (isometric) in separate visits. Results: The results revealed a marked drop in performance, with dynamic force showing a more significant reduction (p < 0.001; d = 1.57) than isometric force (p = 0.015; d = 0.30). After the isometric fatigue task, the DSI increased, indicating a more substantial decline in isometric force (p < 0.001; d = 1.75) compared to dynamic force (p = 0.313; d = 0.08). Following this trend, the DSI decreased post-dynamic fatigue (p < 0.001; d = 0.99) and increased post-isometric fatigue (p < 0.001; d = 3.11). Conclusion: This research underscores the need to consider fatigue's task-specific effects on the DSI, enabling more tailored training methodologies for athletes. [ABSTRACT FROM AUTHOR]