Journal of Strength and Conditioning Research最新文献

Abstract: Molina, R, Lapresa, D, Arana, J, Álvarez, I, and Salazar, H. Wellness and session rating of perceived exertion in professional basketball players within different weekly contexts. J Strength Cond Res XX(X): 000-000, 2024-The objective of this article was to analyze the level of well-being-through the wellness questionnaire-and the training load-based on the session rating of perceived exertion (sRPE)-in professional basketball players within different weekly contexts during the season 2020/2021. The team analyzed played 2 competitions: Endesa League (Asociación de Clubes de Baloncesto)-the highest level of competition in Spain-and the Basketball Champions League at the European level. Non-parametric statistics have been used because of the size of the sample and the ordinal nature of the scores. The contrast of related groups has not been significant for the wellness variable, remaining stable scores throughout different weekly contexts (weeks without competition, regular weeks with 1 game, and congested weeks with 2 or more games). Regarding the training load results, a significant effect size has been found in the contrast of medians depending on the proximity to the game in regular weeks and congested weeks, while in weeks without competition, moments of load alternation have been detected. This work is an example of the practical application of the wellness-sRPE relationship as an effective indicator within the week periodization.

Abstract: Harry, JR, Park, S, Stewart, M, Hite, M, Simms, A, Larsen, M, and Bishop, C. Asymmetry during landing impacts following jumps with aerial rotation in collegiate men's basketball players. J Strength Cond Res XX(X): 000-000, 2024-This project explored whether (a) landing performances and (b) impact force asymmetries were different during countermovement jump (CMJ) landings with leftward versus rightward aerial rotation in 19 collegiate men's basketball players. Replicated single-subject analyses were performed to identify differences that were both statistically significant and important for each individual. Countermovement jump landing performance and loading, attenuation, and control phase durations were compared, while interlimb vertical ground reaction forces (GRF) were compared during each phase of CMJ landings with leftward and rightward rotations, respectively, using the model statistic and coefficient of variation techniques. The model statistic provided random chance probability (α = 0.05). The coefficient of variation provided whether differences exceeded the largest amount of variation from each limb or rotation direction. The bilateral asymmetry index (BAI; difference between dominant and nondominant limbs divided by the sum of the 2 limbs) was also calculated. Statistically significant (model statistic results) and important (coefficient of variation results) differences in landing performance were detected between rotation conditions in 4 subjects. Most subjects did not display significant and important asymmetries for the changes of vertical GRF during any phase of CMJ landings with leftward or rightward rotations. Large amounts of intra-individual variation seem to be an influential factor for these results, as basketball players seem to have unrefined landing strategies that could require targeted training. Because the BAI values reached as high as ± 531% without coinciding with significant and important asymmetry, researchers and practitioners may need to reevaluate the way in which asymmetry indices are interpreted.

Abstract: Lahti, A, Grundberg, A, Stenman, E, and Sundquist, K. Physical characteristics of Swedish female professional ice hockey players allowed body checking. J Strength Cond Res XX(X): 000-000, 2024-In ice hockey, physical characteristics impact sporting performance. This study aims to describe body height, body mass, and body mass index (BMI) in professional female ice hockey players in the Swedish Women's Hockey League (SDHL), which is unique as it is (so far) the only women's league in the world that allows body checking. This study also compares physical characteristics by players' position and the players in SDHL with the nonchecking female North American Elite League (PWHL). In addition, attitudes toward body checking are examined. All 225 players registered in SDHL 2023/2024 were invited to participate. Data from 159 included players (71%) aged (mean ± SD) 23.6 ± 4.5 years were analyzed. Body height, body mass, BMI, and attitudes toward body checking were assessed through a self-reported questionnaire. The mean body height was 169.1 ± 5.5 cm, body mass 68.4 ± 6.7 kg, and BMI 23.9 ± 1.9 kg·m-2. No significant differences were found by player position or between the players in SDHL and PWHL. In total, 88% believed that it was good to introduce body checking in women's ice hockey and 64% did not believe that introducing body checking would increase the number of injuries. The observed characteristics may represent baseline reference values of physical characteristics in female ice hockey players allowed body checking. There is currently no difference in physical characteristics by players' positions or between checking and nonchecking leagues although such differences may occur in the future. Most players were positive toward body checking in women's ice hockey and did not believe that the number of injuries would increase by introducing it.

Abstract: Lockie, RG, Young, MA, Lanham, SN, Orr, RM, Dawes, JJ, and Nagel, TR. Retrospective analysis of grip and index finger strength, job-specific scenario, and shooting performance in incumbent law enforcement personnel and cadets. J Strength Cond Res XX(X): 000-000, 2024-This study investigated grip and index finger strength, and scenario performance, of incumbent deputy sheriffs/police officers. All personnel (incumbents; n = 15) and cadets (n = 44) completed a job-specific scenario (step-ups, jumping jacks, sprawls, strikes, drags, carries, simulated fight) for time. Dominant grip strength (DGS) and nondominant grip strength (NDGS) and dominant index finger strength (DIFS) nondominant index finger strength (NDIFS) were measured pre- and postscenario. Incumbents and cadets then completed a 6-steel plate shooting test. Steel time (time to hit all plates) and number of shots required were recorded. Between-group differences in scenario time, steel time, and shots fired were analyzed by a univariate analysis of covariance (ANCOVA) (p < 0.05; covariates: sex, age). Relationships between grip and index finger strength with scenario variables were derived with partial correlations controlling for sex and age (p < 0.05; incumbents and cadets analyzed separately). A repeated measures ANCOVA (p < 0.05; covariates: sex, age) investigated between-group differences in grip and index finger strength, and whether there were changes postscenario. Cadets completed the scenario faster than the incumbents (p = 0.045). The incumbent group had a nonsignificant 71% faster steel time and required 40% fewer shots, and experienced a decrease in DGS and NDGS (p ≤ 0.013) postscenario. Pre- and post-DGS and NDGS, pre-DIFS, and post-NDIFS significantly related to scenario time for the cadets (r = -0.311 to -0.503). Incumbents had fitness limitations that affected scenario time but demonstrated better shooting skills. Even with grip strength decreases postscenario, incumbents likely had sufficient strength to complete the shooting task. Cadets may be more reliant on general fitness when completing job-specific scenarios because they require further skill development.

Abstract: Hardy, SGJ, Stelzer-Hiller, OW, Edwards, KM, and Freeston, J. Criterion validity and reliability of a new medicine ball rotational power test. J Strength Cond Res XX(X): 000-000, 2024-This study assessed the validity and reliability of 2 medicine ball rotational power assessments, the novel push for maximum velocity by radar (MBvel), and the commonly used push for maximum distance by tape measure (MBdis), against the criterion reference 3-dimensional motion capture (MoCap) to identify the best-practice field-based assessment. Fifteen professional female cricketers volunteered for 2 testing sessions each comprising of a specific warm-up and 24 (12 MBvel, 12 MBdis) maximal throws of a 2-kilogram medicine ball. Radar velocity and tape measure distance were compared with MoCap velocity and projectile motion calculated distance overall, and by dominant and nondominant sides. Statistical analysis included intraclass correlations (ICCs) for accuracy (1, 1) and reliability (3,1), Bland-Altman plots for bias precision and limits of agreement, linear regression (R2) for variance, and Pearson's (r) for correlation. Significance was set α = 0.05. MBvel demonstrated excellent accuracy (ICC = 0.97 [0.97-0.98]), and nearly perfect agreement for bias (-0.09%) and precision (1.49%). Side-to-side analysis showed the same profile for MBvel dominant (ICC = 0.96 [0.95-0.97], bias -0.15%, precision = 1.55%) and nondominant sides (ICC = 0.97 [0.96-0.98], bias -0.05%, precision = 1.53%). MBvel demonstrated excellent reliability overall (ICC = 0.94 [0.82-0.98]) for dominant (ICC = 0.88 [0.69-0.97]) and nondominant sides (ICC = 0.93 [0.80-0.98]). MBdis showed poor accuracy (ICC = 0.38 [0.28-0.47]), large bias (12.43%), lower precision (4.55%), and moderate reliability (ICC = 0.72 [0.32-0.90]). The MBvel assessment validly and reliably measures rotational power performance, enabling practitioners to profile, benchmark, and assess the quality in the field.

Abstract: Marins, EF, de Araújo Rocha Junior, V, Castagna de Freitas, F, Rossy e Vasconcelos Júnior, J, Aparecido Minervi, N, Dawes, JJ, and Boscolo Del Vecchio, F. Unraveling the boundaries of police physical fitness: normative values of police physical fitness based on a representative sample of 8000 federal highway police officers aged 21-70 years from Brazil. J Strength Cond Res XX(X): 000-000, 2024-To develop age- and sex-based normative tables related to physical fitness components (cardiorespiratory fitness, muscular endurance, and power) from a representative sample of the Brazilian police population. This analysis included archived data from 8,628 police officers evaluated in 4 physical fitness tests (PFTs) conducted in 2020. Cardiorespiratory fitness was assessed by a 12-minute run test, endurance by the 60-s sit-up and push-up tests, and lower-limb muscular power by standing broad jump test. Additive quantile regression was used to determine percentiles and estimate age-based charts for each test by sex. Reference values were described from these data. Significant differences between sexes for all measures of physical fitness (p < 0.01, d = 0.14-1.68), except for upper-limb endurance, were observed (p > 0.05, d = 0.05). There was a decline in performance in all measures of physical fitness among police officers of both sexes with advancing age categories, with younger groups performing better than older groups (p < 0.05, d = 0.27-3.17). Age charts and curves were created using the output of quantile regression of reference values for cardiorespiratory fitness, abdominal and upper-limb endurance, and lower-limb power corresponding to the 10th, 20th, 40th, 60th, 80th, and 90th percentiles at all ages, for both sexes. Classificatory tables were presented by age and sex, with reference values for the tests using percentile values. Lower levels of physical fitness were observed with aging, and men exhibited higher overall values than women. The reference values presented can serve as a guide for interpreting the results of PFTs obtained by other police institutions and developing training programs to enhance health, fitness, and performance.

Abstract: Kubiak, SM, Starns, EA, Wehler, RJ, Church, LA, and Roberts, JC. Evaluating disability inclusivity in accreditation standards for exercise science-related programs: a scoping review. J Strength Cond Res XX(X): 000-000, 2024-The purpose of this scoping review was to determine the level of inclusivity for disability-related language within accreditation standards for exercise science-related bachelor and graduate education programs. Standards from 4 U.S. exercise science-related programmatic accrediting organizations were included in this study. Using the World Health Organization's International Classification of Functioning, Disability, and Health (ICF) framework, each standard (N = 1,043) was classified as either containing disability-related language or not based on the 8 ICF function and structure categories. Owing to the broad ICF disability framework, standards were further analyzed using open coding. Frequencies and percentages of exercise science-related accreditation standards that included or lacked disability language and to what extent were reported. Of the 1,043 standards, 417 were classified as including language related to at least 1 of the 8 ICF categories. Using a more specific disability definition from the Centers for Disease Control and Prevention, standards were further analyzed and coded as "knowledge of" disability (n = 281; 27%), "application of" knowledge (n = 64; 6%), 21 standards were classified as both (2%), and 677 (65%) were classified as having no disability language. "Knowledge of" and "application of" coded standards were further organized according to subcodes (disability, risk factors, both disability and risk factors, and basic life support or emergency care). The lack of inclusive language identified revealed a critical need to reexamine the inclusivity of disability in accreditation standards to ensure educational curricula equip future fitness professionals with the education and experience needed to confidently and effectively serve persons with disabilities.

Abstract: Bishop, C. Using ratio data in strength and conditioning: component parts hold the key. J Strength Cond Res XX(X): 000-000, 2024-In strength and conditioning, ratio data are made up of more than 1 component part and are now commonplace in both research and practice, with an abundance of metrics from strength and jump testing being used as part of the ongoing monitoring process. Given these data have been used for many years, their inherent issues may not be obvious to all practitioners. However, ratio data often exhibit greater measurement error than their individual component parts. In addition, monitoring alterations in ratio data also presents challenges, given there is more than 1 way that the resultant test score can change. This brief review provides some practical examples to illustrate these challenges but also some viable solutions to guide practitioners on how the concurrent monitoring of ratios and their component parts can help guide decision-making in day-to-day practice.

Abstract: Henderson, FJ and Shimokochi, Y. Inertial one-leg squat training and drop jump biomechanics in athletes with anterior cruciate ligament reconstruction after return to sport. J Strength Cond Res XX(X): 000-000, 2024-Athletes with anterior cruciate ligament reconstruction (ACLR) display altered jumping mechanics persisting long after returning to sport (RTS). We investigated the effects of flywheel rear leg elevated (Bulgarian) split squat (RLESS) training on single-leg drop jump (SLDJ) biomechanics in athletes with ACLR after RTS. Eleven competitive athletes with unilateral ACLR (546 ± 270 days postsurgery) performed 16 sessions of 1 set of deep knee flexion RLESS until failure in the reconstructed leg (REC) using a flywheel. Using motion capture and force plates, jump height and leg joint contribution were calculated during a 30-cm SLDJ, alongside peak vertical ground reaction force (vGRF), lower extremity joint peak angle, displacement, work, peak internal moment, and peak power. After training, the jump height increased in REC (p < 0.05) but not the intact leg (INT), although the jump height in REC remained lower than that in INT. Reconstructed leg knee contribution increased, whereas REC hip contribution decreased, so no bilateral difference remained after training. Although jump height remained unchanged in INT, several kinematic and kinetic variables changed significantly. Vertical ground reaction force showed no significant difference while asymmetry in internal knee varus moment disappeared, suggesting that some risk factors of ACL injury were reduced. Therefore, athletes with ACLR show persistent deficits in jumping performance, but adding 8 weeks of flywheel RLESS in REC can safely improve performance and restore normal joint contribution. Besides, coaches should be aware of possible changes in jumping mechanics in INT despite unchanged jumping performance when monitoring athletes with ACLR.