Journal of Strength and Conditioning Research最新文献

Abstract: Wright, WC, Fedewa, MV, Aguiar, EJ, Winchester, LJ, Schumacker, RE, and Esco, MR. Accuracy of three field-based devices for measuring counter movement jump performance in elite female volleyball players. J Strength Cond Res 40(1): 112-117, 2026-The purpose of this study was to determine the accuracy of 3 field-based methods for assessing countermovement jump (CMJ) performance in elite female volleyball players, using force plate (FP) data as the criterion standard. Sixteen collegiate female volleyball players (age = 19.4 ± 1.5 years, height = 176.2 ± 10.6 cm, body mass = 71.5 ± 11.1 kg) performed the CMJ while being simultaneously measured by a jump-and-reach device (JR), linear position transducer (LPT), mobile phone application (APP), and a criterion FP system. CMJ height from the FP (36.16 ± 3.88 cm) was significantly lower than the JR (39.53 ± 5.18 cm, p < 0.01) and LPT (48.23 ± 4.44 cm, p < 0.01) but slightly higher than the APP (35.32 ± 3.75 cm, p < 0.01). In addition, the APP displayed the strongest correlation ( r = 0.99, p < 0.01) and smallest standard error of estimate (SEE ±0.27 cm) and 95% limits of agreement (±0.57 cm) compared with the other 2 devices. For CMJ, the mean power from the FP (2,243.00 ± 458.03 W) was significantly different from JR (2,615.69 ± 798.03 W, p = 0.02) and APP (1,354.31 ± 241.98 W, p < 0.01), but not the LPT (2,447.08 ± 559.32 W, p = 0.40). Although the correlations for mean power ( r = 0.61-0.76) between the field devices and criterion were significant ( p < 0.05), the SEE's (range ±310.90 to ±377.09 W) and limits of agreement (range ±655.28 to ±1,064.08 W) were considerably large. Based on the results, the APP seems to provide the most valid CMJ height measures. However, the caution should be used for assessing CMJ mean power with the field tools.

Abstract: Meira, Â, Ferreira Tramontin, A, Ribeiro, G, Santos de Oliveira Cruz, R, Alves de Aguiar, R, Klitzke Borszcz, F, and Caputo, F. Neuromuscular performance impairment: Exploring the power-force-velocity recovery profiles in local and nonlocal muscles. J Strength Cond Res 40(1): e9-e16, 2026-This study examined the effects of neuromuscular impairment on the time course of changes in the force-velocity-power profile in local (i.e., lower limb, assessed through back squat [SQ]) and nonlocal (i.e., upper limb, assessed through bench press [BP]) muscle groups following a repetitive lengthening protocol (RLP). Sixteen physically active men (age: 23 ± 3 years; 1 maximum repetition SQ relative to body mass: 1.5 ± 0.4 kg·kg -1 ) performed an RLP involving 5 sets of maximal 25 drop jumps designed to induce neuromuscular disruption. Back squat and BP exercises were used to assess neuromuscular performance changes in local and nonlocal muscles, respectively, by means of maximal theoretical force (F 0 ), velocity (V 0 ), and power output (Pmax) at baseline and at 24, 48, and 72 hours post-RLP. Delayed onset muscle soreness was measured at 0, 24, 48, and 72 hours. Significant reductions in F 0 and Pmax were observed in both exercises, with greater impairments in the SQ ( p ≤ 0.0001). V 0 was reduced in the SQ and remained unchanged in the BP, SQ change differed significantly from BP ( p = 0.008). F 0 remained suppressed across all time points ( p < 0.001), Pmax exhibited progressive reductions, peaking at 72 hours ( p = 0.001). Delayed onset muscle soreness peaked at 48 hours and resolved by 72 hours. These findings demonstrate that RLP impairs neuromuscular performance beyond the directly affected muscles, with persistent force deficits and task-specific reductions in velocity and power. This underscores the importance of monitoring both local and nonlocal muscles recovery kinetics when designing training and rehabilitation protocols.

Abstract: Bartkowiak, S, Kozieł, S, Krzykała, M, Karpowicz, K, Konarski, JM, and Malak, B. Are sex differences in youth weightlifting performance explained by fat-free mass? A controlled analysis. J Strength Cond Res 40(1): 68-75, 2026-This study examined sex differences in weightlifting performance among youth athletes, emphasizing the role of fat-free mass (FFM), strength, and power. Fifty-three competitive weightlifters (28 male, 25 female) aged 13-15 years were evaluated using bioelectrical impedance analyses to estimate FFM, along with assessments of hand grip strength, squat jump (SJ) power, and isometric mid-thigh pull force. Competition outcomes for the snatch, clean & jerk (C&J), and total weight lifted were recorded. Male weightlifters demonstrated significantly higher absolute strength outputs compared with female weightlifters ( p < 0.001). Regression analyses identified SJ power normalized to FFM as the strongest predictor of performance in male weightlifters across the snatch ( r2 = 0.3742, p < 0.001), C&J ( r2 = 0.3742, p < 0.001), and total ( r2 = 0.3945, p < 0.001). In addition, results from the forward stepwise linear regression indicated that waist-to-hip ratio emerged as a significant, sex-specific predictor of C&J performance ( p > 0.05). These findings underscore the importance of FFM and lower-body explosive strength in youth weightlifting success. However, inherent neuromuscular and biomechanical differences between sexes contribute to persistent performance gaps. The results support the implementation of sex-specific training strategies that target these unique physiologic profiles to optimize performance outcomes in youth weightlifters.

Abstract: Coffey, K, Pezzullo, L, Nixon, RM, Bolling, J, and Vincent, HK. A 10-year analysis of resistance training-related injuries treated in emergency departments: Are patterns shifting with more participation of women over time? J Strength Cond Res 40(1): e1-e8, 2026-This study reports current sex-related injury patterns associated with resistance training-related data from the National Electronic Injury Surveillance System (NEISS). This retrospective study includes patients seeking care for "resistance training" activity as defined by NEISS, encompassing the use of weight machines, barbells, dumbbells, and kettlebells. The prevalence, type and anatomical site of injuries, and hospital outcome were compared by sex. In total, 15,348 cases were included (20.40% female; 22.8 ± 6.3 years). Females sought care more frequently than males for accidental injuries including fracture (odds ratio [OR] = 1.27 [1.11-1.46]), contusion/laceration (OR = 1.52 [1.37-1.69]) and concussion/internal injuries (OR = 2.45 [2.02-2.97]). Males had 20 and 35% greater odds for reporting to the emergency department (ED) for exertional sprains/strains and dislocations, respectively (both p <0.05). Sites more frequently treated in the ED for females were the head, leg, and ankle/foot (all p < 0.050). The trunk was the most commonly injured site for both males and females (40.5 and 31.1%, respectively). Males had more crush injuries (3.10 vs. 2.20%, respectively) and injuries related to pressing movement (7.20 vs. 3.30%, respectively; p < 0.050). Females had more injuries related to dropped equipment (18.50 vs. 12.10%, respectively), falls (8.30 vs. 5.60%, respectively), and being hit by equipment (6.1 vs. 4.10%, respectively) than males ( p < 0.050). Gym environments were the most common injury sites for both sexes. Compared with earlier NEISS data, persistent sex differences exist with injury presentation in the ED, with an increase in concussions/internal injuries in females. Appropriate training regarding set-up and lift execution is critical to minimize these injuries. Prospective tracking that links specific type of lifting activity with specific injuries may provide a better understanding of how to reduce or prevent injuries.

Abstract: Lockie, RG, Beitzel, MM, Alvarez, DA, Sanchez, KJ, Orr, RM, Dawes, JJ, and Dulla, JM. Relationships between physical activity, general health and fitness, and job-specific fitness in law enforcement officers. J Strength Cond Res 40(1): e85-e94, 2026-Sedentary behaviors contribute to police officer fitness declines during their career, which may affect job performance. Physical activity (PA) could benefit general and job-specific fitness. This study derived relationships between PA and general and job-specific fitness in 60 officers (48 men, 12 women) from 1 law enforcement agency. Officers completed a questionnaire assessing PA (weekly strenuous, moderate, mild exercise sessions; activity score) and resistance training (RT) (resistance training frequency [RTF]; weekly sessions for 3 months [RT3M]; sessions in past 7 days [RT7D]). General fitness measures included resting heart rate (RHR), blood pressure, body composition, waist-to-hip ratio (WHR), sit-and-reach, grip strength, push-ups, sit-ups, and the YMCA step test. Job-specific fitness tests included an obstacle course, body drag, climbing tasks, and 500-yard run. Partial correlations controlling for sex calculated relationships between PA and RT with general and job-specific fitness. The sample was quartile split using activity score and examined by univariate analyses. Strenuous PA sessions related to RHR, WHR, push-ups, and sit-ups; activity score related to RHR and sit-ups ( r = ±0.27-0.36). Resistance training frequency related to RHR, WHR, push-ups, and sit-ups; RT3M related to RHR, push-ups, and sit-ups; RT7D related to push-ups and sit-ups ( r = ±0.31-0.43). The top quartile had a lower RHR than the bottom quartile and greater sit-ups than the bottom 2 quartiles ( p ≤ 0.03). There were no significant results for PA and job-specific fitness. Strenuous PA related to lower RHR and WHR, and better muscular endurance. Resistance training frequency related to lower RHR and better muscular endurance. General PA may not be sufficient for training job-specific fitness.

Abstract: Haghighi, AH, Shandiz, HH, Kakhak, SAH, Shahrabadi, H, Coswig, V, and Gentil, P. Plyometric and ballistic training have similar effects on young amateur male wrestlers' athletic performance. J Strength Cond Res 40(1): 98-105, 2026-This was a quasi-experimental study with a pretest and post-test design aimed at investigating the effects of resistance-plyometric training (RPT) compared with resistance-ballistic training (RBT) on the athletic performance of young amateur male wrestlers. Twenty wrestlers aged 16-18 years were randomly divided into RPT and RBT groups. The experimental groups participated in 3 sessions per week of the RPT or RBT program for 6 weeks in addition to their wrestling training routine during the preseason period. Before and after the intervention, the subjects were assessed for bench press strength, leg press strength, bench press endurance, leg press endurance, t test agility, 3-kg medicine ball throwing performance, Sargent jump performance, and specific wrestling tasks (flying mare, duck under, and rear throw). The results showed that both the RPT and RBT programs improved physical fitness (except for medicine ball throwing, which did not improve in RBT) and specific task performance (flying mare, duck under, and rear throw) with p < 0.05. There were no differences between the RPT and RBT programs in any of the physical fitness indicators or specific task performances ( p > 0.05). Considering that no significant difference was observed between the 2 types of training, young amateur male wrestlers could benefit from both RPT and RBT programs to improve their physical fitness and performance on specific tasks.

Abstract: Petushek, E, Breen, S, Myer, GD, Dupuis, BP, Dorgo, S, Ebben, W, and Krosshaug, T. Competency and confidence in qualitative biomechanical assessment of exercise technique among exercise professionals. J Strength Cond Res 40(1): 16-23, 2026-Understanding resistance exercise technique is critical for exercise professionals, but research on this as a specific competency is lacking. This study evaluated resistance exercise technique analysis competency, confidence, and perceived importance in a diverse set of exercise professionals. A 30-question true/false and multiple-choice instrument was developed that focused on application of biomechanical principles to resistance exercises. Subsequently, instrument data were collected from 310 exercise professionals (e.g., personal trainers, strength coaches, physical therapists), and overall percentage of correct answers was calculated across the 30 questions. Perceived importance and confidence in abilities were also assessed. Overall scores were compared across occupation and years of experience using 1-way ANOVA and follow-up t -tests correcting for multiple comparisons. Wilcoxon rank sum tests were used to compare confidence and importance data. Overall percentage of correct answers was 50%. There were no significant differences in scores among exercise professionals or years of experience ( p > 0.05). Subjects were most confident in choosing appropriate exercises to target specific muscles (72%) and identifying poor technique (70%) and least confident about optimizing exercises to maximize activation (45%). About 97% of professionals expressed a desire to learn more about assessing resistance exercises. Exercise professionals in this cohort lacked knowledge in biomechanics related to resistance exercise, exercise prescription, assessment, and modification. Most exercise professionals believed these skills were very important and desired to learn more.

Abstract: Tremblay, M, Prunault, C, Vesco, C, Abboud, J, and Descarreaux, M. Validation of a supine upper-body power test in physically active male and female adults using a medicine ball with accelerometer. J Strength Cond Res XX(X): 000-000, 2025-The purpose of this study was to validate a supine version of a medicine ball throw test for assessing upper-body power (UBP) in physically active male and female adults. Between session test-retest reliability, convergent validity, and agreement with the seated medicine ball throw protocol (SMBT) and criterion validity of the supine protocol were examined. In addition, the sensitivity of the supine protocol to upper-body neuromuscular fatigue was compared with grip strength measures. Thirty subjects (21 males, 9 females; mean age 26.93 ± 4.26 years) completed 2 experimental sessions 24-72 hours apart. In session 1, UBP was assessed using both the SMBT protocol and supine throw protocols, with peak velocity score (m·s-1) measured by an accelerometer-equipped 4-kilogram medicine ball. Grip strength was measured before, between, and after each medicine ball throw protocol. In session 2, grip strength and the supine throw protocol were assessed pre- and postfatigue, induced by repeated rounds of a push-up protocol. Results showed excellent test-retest reliability (intraclass correlation [2,1] = 0.94, 95% CI [0.88, 0.97]) of the supine throw protocol between sessions, and high correlation and agreement with the SMBT protocol (r = 0.92, p < 0.001). Results of session 2 showed a significant fatigue-induced reduction in UBP supine throw performance (p < 0.01), but grip strength changes were inconsistent. These findings suggest that the supine medicine ball throw protocol is a reliable and valid measure of UBP. This assessment seems to offer greater standardization and sensitivity to fatigue during specific targeted upper-body exercise compared with grip strength assessments.

Abstract: Wohlgemuth, KJ, Conner, MJ, Burnham, E, and Mota, JA. Occupational Health Disparities: A Profile of Firefighters and Police Officers. J Strength Cond Res XX(X): 000-000, 2025-Firefighters and law enforcement officers belong to a group of workers within the public safety sector in the U.S. workforce. Public safety workers have physically demanding jobs, and the effect of the specific occupation on health outcomes deserves further elucidation. The primary purpose of this study was to examine differences in demographic characteristics between police officers and firefighters. A secondary purpose was to quantify the effect of occupation on cardiopulmonary function across age. Cardiometabolic, aerobic capacity, and body composition data from yearly agency screenings were retrospectively assessed for 399 workers (firefighters, n = 200; police officers, n = 199). To quantify the influence of occupation and age on cardiopulmonary function (V̇o2peak, METs), separate linear mixed-effect models were employed. The a priori criterion for significance was set at p = 0.05. The results show that 90.5% of public safety workers were categorized as overweight or obese, and 50.4% were considered obese. Firefighters displayed better cardiopulmonary function (e.g., higher V̇o2) than police officers (+2.05, t = 4.94, p = 0.01); however, not greater than industry recommendations. The present study indicates both public safety occupations have negative impacts on cardiopulmonary function across our sample of workers. Although, firefighters may have less impairments to health when compared with police officers.

Abstract: Cleary, A, Winchester, JB, Cochrane-Snyman, KC, and McBride, JM. The relationship between the NBA draft combine tests, advanced performance metrics, and perceived performance in National Collegiate Athletic Association Division I men's basketball. J Strength Cond Res XX(X): 000-000, 2025-The NBA Draft Combine (NBADC) assesses an athlete's size, length, and athleticism. Advanced metrics such as player efficiency rating (PER) and Win Share/40 (WS/40) quantify basketball performance. This study explored relationships between NBADC metrics, performance metrics, and perceived performance in a National Collegiate Athletic Association DI Men's Basketball team. Thirteen scholarship athletes (age 20.1 ± 0.64 years, height 1.9 ± 0.1 m, mass 93.9 ± 10.9 kg) participated. Players and coaches ranked each player at their position, creating perceived performance rankings (player rank [PR] and coaches rank [CR]). A Spearman's rank correlation was performed using PER, WS/40, PR, and CR as dependent variables, with anthropometric and physical data as independent variables. Statistical significance was set a priori ≤0.05. Stepwise linear regression identified predictive relationships. Win Share/40 significantly correlated with maximum vertical jump (MVJ) (ρ = 0.589, p ≤ 0.05). Maximum vertical jump explained 35% of WS/40 variability, and MVJ with body composition (BC) predicted 61.4%. Player efficiency rating and raw no-step vertical jump predicted 87.4% of WS/40. Coaches rank and standing reach explained 73.9% of WS/40, while CR alone explained 64.1% of PER. Results suggest lower body muscular power and body composition significantly relate to basketball performance. Coaches assessing players and projecting future contributions should prioritize vertical jump metrics and body composition over other NBADC assessments.