bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interday Reliability of a Testing Battery to Assess Lateral Symmetry and Performance in Well-Trained Volleyball Players
Authors: Iglesias-Caamaño Mario , Álvarez-Yates Tania , Carballo-López Javier , Cuba-Dorado Alba , García-García Oscar 
Published: August 2020

Abstract
Iglesias-Caamaño, M, Álvarez-Yates, T, Carballo-López, J, Cuba-Dorado, A, and García-García, O. Interday reliability of a testing battery to assess lateral symmetry and performance in well-trained volleyball players. J Strength Cond Res 36(4): 895–901, 2022—This study aimed to determine the relative and absolute interday reliability of a testing battery for lateral asymmetry detection and performance in well-trained volleyball players and to determine whether retaining for analysis the best or the average value of 3 attempts would modulate the interday reliability and the magnitude of asymmetry. Thirteen Superleague-2 male volleyball players performed on 3 different days a 5-test battery composed of 4 tests for assessing muscle asymmetries: active knee extension, Y-balance test (YBT), modified 20-yard shuttle run (M-20Y), and single-leg countermovement jump; and one for volleyball sports performance: attack jump (AJ). The intraclass correlation index and coefficient of variation (CV) together with the standard error of measurement (SEM, %SEM) and the minimum detectable change (MDC, %MDC) were taken to calculate relative and absolute reliability. Two-way repeated-measures analysis of variance was used to establish the differences between the best value and the average value in each session. The low %MDC (<10%) suggests that all the tests that make up the testing battery would have good sensitivity to detect possible asymmetries. All tests have shown an excellent interday absolute reliability (CV <4.5%; %SEM < 5%), both when retaining the best value and the average value of the 3 attempts. In addition, AJ and YBT (on both legs) obtained a good-excellent relative reliability, whereas the M-20Y test seems to show a lower relative reliability. Retaining the best value or the average value to determine the magnitude and direction of asymmetry seems to be equally reliable with no differences between both values.
Interscholastic Athletics and Bone Strength: The Iowa Bone Development Study
Authors: Pashkova Anna , Hartman Jeffrey M. , Letuchy Elena M. , Janz Kathleen F. 
Published: August 2020

Abstract
Pashkova, A, Hartman, JM, Letuchy, EM, and Janz, KF. Interscholastic athletics and bone strength: the Iowa bone development study. J Strength Cond Res 36(5): 1271–1276, 2022—The objective of this study was to determine the relationship between adolescents' participation in various interscholastic sports and differences in bone strength outcomes. Subjects (N = 380) were recruited from the Iowa Bone Development Study and categorized based on sport participation into 3 power groups: no-power, low-power, and high-power. Sports such as basketball, cheerleading/poms, gymnastics, volleyball, track, football, tennis, and soccer were considered high-power. Peripheral quantitative computed tomography (pQCT) was used to determine bone measures of polar stress-strain index (measure of torsion strength), cortical content (measure of cortical bone size and area at the 66% tibia site), and bone strength index (measure of compression strength based on total bone density and area at the 4% tibia site). Adjusted pairwise comparison for group least squares means high-power sport participation compared with no-power sport participation showed significant differences in all bone strength outcomes for both men and women (p value < 0.01). There was a significant difference in all bone strength measures between low-power and no-power groups for men (p value < 0.05), but not women. Because of decreasing levels of physical activity in late adolescence, the promotion of high-power sports may be particularly important for optimal bone development in the final years before peak bone mass.
Influences of the Stretch-Shortening Cycle and Arm Swing on Vertical Jump Performance in Children and Adolescents
Authors: Gillen Zachary M. , Shoemaker Marni E. , McKay Brianna D. , Bohannon Nicholas A. , Gibson Sydney M. , Cramer Joel T. 
Published: August 2020

Abstract
Gillen, ZM, Shoemaker, ME, McKay, BD, Bohannon, NA, Gibson, SM, and Cramer, JT. Influences of the stretch-shortening cycle and arm swing on vertical jump performance in children and adolescents. J Strength Cond Res 36(5): 1245–1256, 2022—This study compared the influences of the stretch-shortening cycle and arm swing on vertical jump performance during static jumps (SJs), counter-movement jumps (CMJs), and CMJs with arm swing (CMJAs) in young male and female athletes. Twenty-one boys (age = 12.1 ± 1.1 years) and 21 girls (age = 12.1 ± 1.1 years) performed SJs, CMJs, and CMJAs on force plates that sampled at 1 kHz. Measurements included peak force, rate of force development, peak power (PP), eccentric impulse (ECC), concentric impulse (CON), estimated jump height (JH), and changes in PP and JH across vertical jumps. Measurements of growth included age, maturity offset, height, body mass, fat-free mass, and thigh muscle cross-sectional area. Analyses of variance were used to analyze growth measurements across sex, as well as vertical jump outcome measures. Pearson product moment correlation coefficients were used to determine the relationships between changes in PP and JH across vertical jumps and growth measurements. There were differences in PP and JH such that SJ < CMJ < CMJA (p < 0.001), and ECC such that SJ < CMJA < CMJ (p ≤ 0.048). Changes in PP were greater from the SJ to CMJ than CMJ to CMJA (p ≤ 0.001). The change in PP from the SJ to CMJ exhibited moderate-to-high relationships with growth measurements for boys and girls (r = 0.543–0.803). Because young children may not have the skeletal musculature or strength necessary to absorb and reapply large eccentric preloading forces, future studies should consider using the CMJA, rather than the CMJ, to maximize vertical jump performance and minimize ECC. Coaches and practitioners can expect approximately 27–33% greater PP and 15–17% greater estimated JH when an arm swing is included during the CMJ.
The Effect of Different Rest Intervals Between Agonist-Antagonist Paired Sets on Training Performance and Efficiency
Authors: Behenck Cristiano , Sant'Ana Haroldo , Pinto de Castro Juliana Brandão , Willardson Jeffrey M. , Miranda Humberto 
Published: August 2020

Abstract
Behenck, C, Sant'Ana, H, Pinto de Castro, JB, Willardson, JM, and Miranda, H. The effect of different rest intervals between agonist-antagonist paired sets on training performance and efficiency. J Strength Cond Res 36(3): 781–786, 2022—The purpose of this study was to verify the effect of different rest intervals (RIs) between agonist-antagonist paired sets (APS) on training performance and efficiency. Eighteen recreationally trained men (age: 21.5 ± 2.1 years, body mass: 74.5 ± 10.4 kg, height: 1.75 ± 0.04 m, body mass index: 24.4 ± 3.7 kg·m−2) completed 4 sessions. During each session, a 10-repetition maximum load was used for 3 APS of Bench Row + Bench Press and Lat Pull-down + Overhead Press with RI between APS sequences of 1, 2, 3 minutes (min) or self-selected RI (SRI). Total training volume (TTV), session time and efficiency were measured in all sessions. The 1-minute RI resulted in significantly less TTV vs. the other conditions (p = 0.000). The 2-minute RI resulted in significantly less TTV vs. the 3-minute RI (p = 0.002), but the SRI was not significantly different vs. the 3-minute RI. For session time, the 1-minute RI was significantly less (p = 0.000) and the 3-minute RI was significantly greater (1-minute and 2-minute RI, p = 0.000; SRI, p = 0.010) than the other conditions. Therefore, the efficiency of the 1-minute RI was significantly greater vs. the other conditions (3-minute RI and SRI, p = 0.000; 2-minute RI, p = 0.001) and the 2-minute RI was significantly greater vs. the 3-minute RI (p = 0.001). There were no significant differences in TTV, session time, and efficiency between the 2-minute RI and SRI conditions. In conclusion, the 2-minute RI and SRI conditions may present a better cost-effectiveness. It is suggested that self-selected RI can provide better performance, whereas 2-minute RI may enable greater efficiency.
Effect of Caffeine on Endurance Performance in Athletes May Depend on HTR2A and CYP1A2 Genotypes
Authors: Guest Nanci S. , Corey Paul , Tyrrell Pascal N. , El-Sohemy Ahmed 
Published: August 2020

Abstract
Guest, NS, Corey, P, Tyrrell, PN, and El-Sohemy, A. Effect of caffeine on endurance performance in athletes may depend on HTR2A and CYP1A2 genotypes. J Strength Cond Res 36(9): 2486–2492, 2022—This investigation determined whether variation in the HTR2A (serotonin receptor) gene modifies the ergogenic effects of caffeine on endurance and further modifies performance by the CYP1A2 genotype. Male athletes (n = 100; 25 ± 4 years) completed 10-km cycling time trials under 3 conditions as follows: 0, 2, or 4 mg of caffeine per kg body mass. Using a randomized, double-blinded, placebo-controlled design, data were analyzed using analysis of covariance to compare changes in cycling time between placebo (0 mg·kg−1) and each caffeine dose and adjusted for the placebo trial and order of treatment. A significance of ρ ≤ 0.05 was used. Subjects were genotyped for HTR2A (rs6313) and CYP1A2 (rs762551). A significant caffeine-HTR2A interaction (p = 0.003) was observed; however, after adjustment for placebo trials, the interaction was no longer significant (p = 0.37). Because of the strong caffeine-CYP1A2 interaction (p < 0.0001) previously reported in these subjects, where the 4-mg dose resulted in divergent effects (slower and faster) on the 10-km cycling time, we conducted a simplified model to examine these same factors by the HTR2A genotype. The post hoc analysis excluded HTR2A CT heterozygotes and 2-mg·kg−1 caffeine trials. Among CYP1A2 fast metabolizers alone, a significant difference (1.7 minutes; p = 0.006) was observed when comparing (4- vs. 0-mg·kg−1 caffeine trials) between the HTR2A CC (n = 16; 2.4 minutes) and TT (n = 7; 0.7 minutes) genotypes. Our results show that 4-mg·kg−1 caffeine improves performance in individuals with the HTR2A CC genotype but only in those who are also CYP1A2 AA fast metabolizers. This study was registered with clinicaltrials.gov (NCT 02109783).
Between-Sex Differences in the Work Sample Test Battery Performed by Law Enforcement Recruits: Implications for Training and Potential Job Performance
Authors: Lockie Robert G. , Beitzel Maria M. , Dulla Joseph M. , Dawes J. Jay , Orr Robin M. , Hernandez Javier A. 
Published: August 2020

Abstract
Lockie, RG, Beitzel, MM, Dulla, JM, Dawes, JJ, Orr, RM, and Hernandez, JA. Between-sex differences in the work sample test battery performed by law enforcement recruits: implications for training and potential job performance. J Strength Cond Res 36(5): 1310–1317, 2022—Law enforcement officers perform a range of demanding job-specific tasks, and these tasks are the same for all officers, regardless of sex. Female officers tend to be at a physical disadvantage compared with male officers, and this could affect their performance in job-specific tasks. This study investigated the between-sex differences in the work sample test battery (WSTB; duplicates what an officer encounters on-duty) in law enforcement recruits. A retrospective analysis was performed on 308 recruits (259 men and 49 women) from 5 training academy classes. The WSTB incorporated 5 tests: a 99-yard obstacle course (99OC), 165-pound body drag (BD), 6-foot chain link fence (CLF), solid wall (SW) climb, and 500-yard run (500R). These tests were typically performed in the last weeks of academy and must be completed to a state-mandated minimum standard for recruits to graduate. Independent-samples t tests (p < 0.05) and effect sizes (d) calculated between-sex differences. Noting that when individual data were considered, there were male recruits who were outperformed by female recruits. However, on average, female recruits were slower on all WSTB tasks than male recruits (p < 0.01). Large effects were present for the 99OC, CLF, and 500R differences (d = 1.26–1.69), a moderate effect for the BD (d = 0.85), and a small effect for the SW (d = 0.56). Slower performance in job-specific tests could translate to slower performance in tasks required on-duty. Training staff should develop the qualities necessary for WSTB performance in female recruits and underperforming male recruits to enhance future job performance.
Bilateral vs. Unilateral Countermovement Jumps: Comparing the Magnitude and Direction of Asymmetry in Elite Academy Soccer Players
Authors: Bishop Chris , Abbott Will , Brashill Calum , Turner Anthony , Lake Jason , Read Paul 
Published: August 2020

Abstract
Bishop, C, Abbott, W, Brashill, C, Turner, A, Lake, J, and Read, P. Bilateral vs. unilateral countermovement jumps: comparing the magnitude and direction of asymmetry in elite academy soccer players. J Strength Cond Res 36(6): 1660–1666, 2022—The aims of this study were to compare the magnitude and direction of asymmetry in comparable bilateral and unilateral countermovement jumps (CMJs). Forty-five elite academy soccer players from under-23 (n = 15), under-18 (n = 16), and under-16 (n = 14) age groups performed bilateral and unilateral CMJs as part of their routine preseason fitness testing. For the magnitude of asymmetry, no significant differences were evident for any metric between tests. However, the eccentric impulse asymmetry was significantly greater than mean force and concentric impulse in both bilateral and unilateral tests (p < 0.01). For the direction of asymmetry, Kappa coefficients showed poor levels of agreement between test measures for all metrics (mean force = −0.15, concentric impulse = −0.07, and eccentric impulse = −0.13). The mean jump data were also presented relative to the body mass for each group. For the bilateral CMJ, significant differences were evident between groups but showed little consistency in the same group performing better or worse across metrics. For the unilateral CMJ, eccentric impulse was the only metric to show meaningful differences between groups, with the under-18 group performing significantly worse than under-23 and under-16 players. This study highlights that despite the magnitude of asymmetry being similar for each metric between comparable bilateral and unilateral CMJs, consistency in the direction of asymmetry was poor. In essence, if the right limb produced the larger force or impulse during a bilateral CMJ, it was rare for the same limb to perform superior during the unilateral task. Thus, practitioners should be aware that bilateral and unilateral CMJs present different limb dominance characteristics and should not use 1 test to represent the other when measuring between-limb asymmetries.
Interaction Between ACTN3 (R577X), ACE (I/D), and BDKRB2 (−9/+9) Polymorphisms and Endurance Phenotypes in Brazilian Long-Distance Swimmers
Authors: Neto Severino L.d.A. , Herrera Jose J.B. , Rosa Thiago S. , de Almeida Sandro S. , Silva Glauber C.B. , Ferreira Carlos E.S. , dos Santos Marcos A.P. , Silvino Valmir O. , de Melo Gislane F. 
Published: August 2020

Abstract
Neto, SLdA, Herrera, JJB, Rosa, TS, de Almeida, SS, Silva, GCB, Ferreira, CES, dos Santos, MAP, Silvino, VO, de Melo, GF. Interaction between ACTN3 (R577X), ACE (I/D), and BDKRB2 (−9/+9) polymorphisms and endurance phenotypes in Brazilian long-distance swimmers. J Strength Cond Res 36(6): 1591–1595, 2022—This study investigated the interactions between the polymorphisms ACTN3 (R577X), ACE (I/D), and BDKRB2 (−9/+9) and their association with endurance phenotypes in Brazilian long-distance swimmers. Twenty-six volunteers (aged 18–30 years) were divided into 2 groups as follows: 19 subelite athletes formed the pool swimming experts (PSE: 400–1500 m) group and 7 elite athletes the open water swimming experts (OWSE: 5–25 km) group. ACTN3 (R577X), ACE (I/D), and BDKRB2 (−9/+9) polymorphisms were genotyped through polymerase chain reaction. A nonathletes control (CON) group derived from studies with the Brazilian population was created. Hardy-Weinberg equilibrium (X2) was observed in all groups. The total genotype score (TGS) associated with endurance phenotypes was used in this study. A significance level was established at p ≤ 0.05. PSE and CON groups had very similar genotyping distribution. The OWSE group had a greater frequency for the genotypes XX (57.1%), ID (57.1%), and the alleles X (71.4%) and I (57.2%) than CON and PSE groups (XX = 21.1 and 21.1%; ID = 47.1 and 52.6% [p > 0.05]; X = 44.0 and 42.1%; I = 45.3 and 42.1%, respectively). Considering BDKRB2, OWSE and PSE groups had a greater frequency of +9/+9 than the CON group (42.9% and 31.6 vs. 27.5%, respectively). Although the expected genotypic distribution was not verified among athletes, the TGS revealed small supremacy of 3–5 typical alleles in the OWSE group (54.8 ± 26.7%) compared with the PSE group (41.2 ± 17.8%) (p = 0.072; confidence interval = 95%; effect size = 0.95). The OWSE group seem to have benefited from the best genotype profile verified for ACTN3 and ACE. However, the results of this work should be approached with caution because of the small number of athletes and polymorphisms assessed.
HIF-1α and NFIA-AS2 Polymorphisms as Potential Determinants of Total Hemoglobin Mass in Endurance Athletes
Authors: Malczewska-Lenczowska Jadwiga , Orysiak Joanna , Majorczyk Edyta , Sitkowski Dariusz , Starczewski Michał , Żmijewski Piotr 
Published: August 2020

Abstract
Malczewska-Lenczowska, J, Orysiak, J, Majorczyk, E, Sitkowski, D, Starczewski, M, and Żmijewski, P. HIF-1α and NFIA-AS2 polymorphisms as potential determinants of total hemoglobin mass in endurance athletes. J Strength Cond Res 36(6): 1596–1604, 2022—The aims of this study were to examine (1) the genotype distribution of rs11549465:C>T of the HIF-1α gene and rs1572312:C>A of the NFIA-AS2 gene; (2) the association between the genes and hematological status in endurance-oriented athletes; and (3) the association between the NFIA-AS2 gene and aerobic capacity in cyclists. Two hundred thirty-eight well-trained athletes (female n = 90, male n = 148) participated in the study. Total hemoglobin mass (tHbmass), blood morphology, intravascular volumes, i.e., erythrocyte volume (EV), blood volume (BV) and plasma volume (PV), and aerobic capacity indices, e.g., peak oxygen uptake (V̇o
2peak), and power at anaerobic threshold (PAT) were determined. In both studied genes, the CC genotype was predominant. In the HIF-1α gene, there were no differences in genotype and allele distribution among athletes from different disciplines and between sexes. The distribution of genotypes and alleles of the NFIA-AS2 gene differed significantly in male athletes; the frequency of A allele carriers (CA + AA) was significantly higher in cyclists than in rowers and middle- and long-distance runners. The athletes with CC genotype of NF1A-AS2 had significantly higher relative values of: tHbmass (total female athletes, cyclists), PV, BV (cyclists), and EV (total male athletes, cyclists) and PAT (cyclists) than A allele carriers (CA + AA genotypes). In conclusion, our study indicates that NFIA-AS2 rs1572312:C>A polymorphism was associated with hematological status in endurance athletes, as well as aerobic capacity indices in male cyclists. It suggests that this polymorphism may be a determinant of quantity of hemoglobin and intrtavascular volumes, which in turn can have an impact on aerobic performance.
A‐Mode Ultrasound Reliability in Fat and Muscle Thickness Measurement
Authors: Ribeiro Guilherme , de Aguiar Rafael A. , Penteado Rafael , Lisbôa Felipe D. , Raimundo João A.G. , Loch Thiago , Meira Ângelo , Turnes Tiago , Caputo Fabrizio 
Published: August 2020

Abstract
Ribeiro, G, de Aguiar, RA, Penteado, R, Lisbôa, FD, Raimundo, JAG, Loch, T, Meira, Â, Turnes, T, and Caputo, F. A-mode ultrasound reliability in fat and muscle thickness measurement. J Strength Cond Res 36(6): 1610–1617, 2022—This study aimed to verify the reliability of the BodyMetrix portable A-mode ultrasound in measuring fat and muscle tissue thickness. Thirty physically active men participated in daily body composition evaluations. The evaluations comprised 2 techniques: (a) graphic technique (GTBM), which measured the fat thickness at 9 body sites (abdomen, axillary, biceps brachii, calf, chest, subscapular, suprailiac, thigh, and triceps brachii), and (b) imaging technique (ITBM), which simultaneously measured the fat and muscle thickness of 6 body surfaces (abdomen, biceps brachii, chest, thigh, trapezius, and triceps brachii). Regarding GTBM, relative reliability was moderate to excellent (intraclass correlation coefficient [ICC]: 0.81–0.98), whereas absolute reliability was acceptable for abdomen, calf, chest, subscapular, suprailiac, and triceps brachii (coefficient of variation [CV]: 6.9–8.8%) but high for axillary, biceps brachii, and thigh (CV: 12.0–17.4%) in measuring fat thicknesses. Concerning ITBM, relative reliability was good to excellent (ICC: 0.93–0.99 and 0.90–0.98), whereas absolute reliability was acceptable (CV: 3.0–9.2% and 3.5–5.9%) in measuring fat and muscle thickness, respectively. These findings suggest that the, GTBM was only reliable in measuring fat thickness of abdomen, calf, chest, subscapular, suprailiac, and triceps brachii, whereas ITBM was reliable in measuring both fat and muscle thickness in all regions, but showed better reliability values in measuring muscle than fat thickness.
The Effects of Three Correction Strategies of Errors on the Snatch Technique in 10–12-Year-Old Children: A Randomized Controlled Trial
Authors: Souissi Mohamed A. , Elghoul Yousri , Souissi Hichem , Masmoudi Liwa , Ammar Achraf , Chtourou Hamdi , Souissi Nizar 
Published: August 2020

Abstract
Souissi, MA, Elghoul, Y, Souissi, H, Masmoudi, L, Ammar, A, Hamdi Chtourou, and Souissi, N. The effects of three corrections strategies of errors on the snatch technique in 10–12-year-old children: A randomized controlled trial. J Strength Cond Res 37(6): 1218–1224, 2023—Sports movement correction is one of the major problems for motor control and learning. Therefore, the purpose of the present study was to determine which of the 3 strategies, i.e., the self-observation method with direct instructions (SO-DI), self-observation alone (SO), or the direct instruction (DI), would be useful for correcting errors during the snatch technique. Forty-eight children with 2 months of experience were randomly assigned to one of 4 training conditions: SO-DI, SO, DI, or control. In this study, the experience lasted 15 sessions. Subjects completed the test sessions before (T0) and after (T1) 12 training sessions and a retention test session after 2 weeks (T2). The Kinovea version 0.8.15 software was used to measure the kinematic parameters of weightlifting performance. After the training intervention, the data showed that the SO-DI group registered a greater improvement in all kinematic parameters compared with the SO, DI, and control groups, and this benefit was present 2 weeks later in the retention test (e.g., the horizontal displacement of the bar in the first pull with respect to the starting position [T1 vs. T0: +32.57 ± 6.69%, d = 1.87, p < 0.001; T2 vs. T0: 25.07 ± 11.55%, d = 1.32, p < 0.001] and the horizontal displacement of the bar between the receiving position and the reference line [T1 vs. T0: 24.34 ± 29%, d = 1.17, p < 0.01; T2 vs. T0: 25.53 ± 30.4%, d = 0.99, p < 0.01]). The results of the present study could have practical implications for physical education teachers because, even if practice is required to improve the technique, the effectiveness of the learning process is essential to enhance learner self-efficacy and motivation.