Journal of Strength and Conditioning Research最新文献

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.

Abstract: Gastin, PB. Defining the role of the High Performance Manager in professional team sport: Perceptions from HPMs in AFL football. J Strength Cond Res XX(X): 000-000, 2025-The role of the high performance manager (HPM) has become increasingly vital in professional team sports, yet little is known about how this role is operationalized within specific sporting contexts. In the Australian Football League (AFL), every club now uses an HPM. This study aimed to examine the professional background, roles, and responsibilities of HPMs in the AFL, and to identify key themes that define their contributions to athlete performance and organizational success. Using a mixed-methods approach, 14 of the 18 AFL HPMs participated in an online survey and a semistructured interview. Quantitative data captured demographics, qualifications, work allocations, and responsibilities, while qualitative data were analyzed using inductive thematic analysis to identify role-specific themes. Subjects were highly experienced and qualified, with a mean of 17.9 years in high performance sport and 9.8 years in roles with management responsibilities. Seven key themes emerged: Athlete Development and Performance, Program Development and Execution, Standards and Expectations, Integration and Collaboration, Leadership and Management, Strategic Alignment, and Helping Others Succeed . Leadership and integration were considered central to their role. High performance managers in the AFL occupy senior leadership roles requiring a unique blend of technical, managerial, and interpersonal skills. High performance managers predominantly managed physical preparation, recovery, rehabilitation, and nutrition services, with varying oversight of different aspects across other disciplines. Their work is crucial to aligning multidisciplinary support systems with strategic football objectives. These findings offer insights for the development of HPM roles in other professional sport settings.

Abstract: McClure, J, Sommer, A, Kraemer, WJ, and Vodovotz, Y. Effects of soy pretzel consumption on blood biomarkers and muscle soreness after intense resistance exercise in healthy, trained males: a preliminary study. J Strength Cond Res XX(X): 000-000, 2025-Intense resistance exercise can cause exercise-induced muscle damage (EIMD), resulting in inflammation and muscle soreness. Soy protein and its isoflavones have been hypothesized to reduce inflammation, enhance antioxidant capacity, and support recovery. This preliminary study examined the effects of a soy soft pretzel (SSP) on soreness and biomarkers of EIMD. Ten trained male athletes aged 19-29 years completed a double-blind, randomized, crossover trial with either SSP or a wheat pretzel (control). Muscle soreness was measured using a visual analog scale, and blood samples were analyzed for markers of inflammation and muscle damage. Urinary isoflavones were measured to confirm compliance. Serum testosterone was notably lower after SSP (14.54 ± 5.07 nmol·L-1) than wheat (16.35 ± 5.76 nmol·L-1; p = 0.0072; d = -0.60). Although interleukin-6 levels declined more quickly starting at 6 hours in the SSP group (d ≈ -0.50), this difference was not statistically significant. Urinary daidzein, genistein, and glycitein levels were all significantly higher (p < 0.001, 0.011, and 0.011; d > 1.0), indicating absorption of soy isoflavones. Soreness ratings showed no significant difference between treatments, likely because of high individual variability (d < 0.20). These results suggest that while soy pretzel intake affects hormonal and isoflavone responses, its impact on soreness and inflammatory markers remains uncertain and requires further study with larger, adequately powered samples. Practically, soy-based recovery snacks could be a convenient, athlete-friendly option that is generally well tolerated; however, coaches and sports nutritionists should interpret these findings as preliminary until more definitive evidence becomes available.

Abstract: Zhang, S, Li, M, Xing, W, Zheng, W, and Zhai, Z. Effects of player characteristics and periodization strategies on external and internal loads, wellness, and recovery in collegiate male basketball players. J Strength Cond Res XX(X): 000-000, 2025-This study investigated the effects of playing time, player role, player position, and training cycles-both microcycles (the six days leading up to a match) and mesocycles (the four weeks preceding competition)-on PlayerLoad (PL), rating of perceived exertion (RPE),well-being (WB), and total quality recovery (TQR) in highly trained collegiate male basketball players. A total of 18 highly trained collegiate male basketball players were monitored across a continuous 2-month, resulting in a total of 804 training session observations. External load was quantified as PL using wearable tracking devices, while internal load was assessed through RPE. Well-being and TQR were measured using digital self-report questionnaires. The key findings showed that high-minute players (>26 minutes) exhibited significantly higher PL (p < 0.05, effect sizes [ES] = 0.34) and RPE (p < 0.05, ES = 0.33) compared with low-minute players (<26 minutes). Positional differences were also reported, with centers reporting significantly lower RPE than forwards (p < 0.05, ES = -0.67) and higher WB than guards (p < 0.05, ES = -0.88). In the microcycle analysis, the highest PL and RPE were observed 5 to 6 days before official matches. Mesocycle analysis showed a significant increase in PL and RPE during week 2, accompanied by a concurrent decrease in TQR. These results demonstrate that playing time, player role, player position, and training cycles significantly influence PL, RPE, WB, and TQR, underscoring the importance of individualized load management within microcycle and mesocycle structures to optimize performance and recovery in collegiate male basketball players.

Abstract: Gantois, P, Farinha, A, Fonseca, FdS, and Ribeiro, J. Effects of a congested match schedule on isometric muscle strength performance in elite futsal players. J Strength Cond Res XX(X): 000-000, 2025-This study investigated the effects of a congested tournament schedule on isometric muscle strength performance in elite futsal players. Twelve elite-level outfield male futsal players (mean ± SD: age = 27.42 ± 5.60 years, body mass = 76.74 ± 8.91 kg, and height = 1.75 ± 0.04 m) from a top-tier Portuguese league team participated in this study. Postmatch neuromuscular fatigue was assessed by measuring the isometric strength of the hip adductors, abductors, and knee flexors on both dominant and nondominant sides. Baseline measurements (MD1) were taken before the first match, with follow-up tests conducted at 24 hours (MD2), 48 hours (rest day), and 72 hours (MD3) postbaseline. Adductor muscle strength in the dominant limb reduced significantly at MD2 (p = 0.026; effect size [ES] = 0.20) and rest day (p = 0.045; ES = 0.28) compared with MD1. Dominant-side hip abduction strength was significantly lower at MD2 (p = 0.003; ES = 0.62), on the rest day (p < 0.005; ES = 0.56), and at MD3 (p = 0.045; ES = 0.41) relative to baseline. No significant changes were found in knee flexor strength across time points (p > 0.05). In conclusion, these findings indicate that a congested schedule reduced hip adduction and abduction strength among elite futsal players, with prolonged decreases in hip abduction strength. By contrast, hip adduction strength displayed faster recovery after a rest day.

Abstract: Field, A, Fischer, A, Read, DB, Sanderson, A, Graham-Smith, P, Birdsey, L, Harper, L, Bramah, C, Page, RM, and Dos'Santos, T. Changes in sprinting and landing mechanics across 120 minutes of soccer-specific exercise. J Strength Cond Res XX(X): 000-000, 2025-The aim of this study was to examine the influence of 120 minutes of simulated soccer match play on sprinting and landing mechanics. Twelve semiprofessional soccer players completed bilateral vertical drop jumps, countermovement jumps, and 30-m sprints at prematch, half-time, full-time, and post-extra time. Two-dimensional frontal plane footage was captured during jumps, and the frontal plane projection angle upon landing was measured. Sprint-running mechanics were assessed using a novel qualitative screening tool. Drop-jump height reduced 12.5% from prematch (0.32 ± 0.02 m) to extra time (0.28 ± 0.02 m, p = 0.002, d = 0.2), 11.1% from full-time to prematch (0.27 ± 0.02 m; p = 0.013, d = 2.2), and 6.3% from full-time to half-time (0.30 ± 0.02 m; p = 0.001, d = 3.0). Average landing force decreased 4.5% at extra time (1,022.7 ± 38.3 N) vs. prematch (1,068.7 ± 38.5 N; p = 0.003, d = 1.2), 5.5% at half-time (1,078.7 ± 38.3; p = 0.001, d = 0.8), and 3.8% at full-time (1,039.5 ± 38.3) vs. half-time (p = 0.015, d = 0.3). Time to stabilization increased 14.3% at extra time (663 ± 34 ms) from 568 ± 34 ms at prematch (p = 0.009, d = 0.3), 13.7% at half-time (572 ± 34 ms; p = 0.004, d = 0.1), and 9.1% at full-time (663 ± 34; p = 0.011, d = 0.2). Relative peak landing force was 6.9% higher at full-time (692.00 ± 44.44%) vs. half-time (644.79 ± 44.44%; p = 0.009, d = 0.4), but 6.2% lower at half-time vs. prematch (684.50 ± 44.28%; p = 0.022, d = 0.6). Sprint mechanics movement quality deteriorated by 29.5% at half-time (2.75 ± 0.26) compared with prematch (1.95 ± 0.27; p = 0.016, d = 0.5), and by 33.4% from prematch to extra time (2.93 ± 0.27; p = 0.013, d = 0.6). Players may experience impaired neuromuscular performance, particularly during landing and sprinting, which may influence movement quality and could contribute to increased injury susceptibility, although this requires further investigation.

Abstract: O'Brien, John J., Coratella, G, and Young, D. Match load analysis of substitutes in elite hurling match-play. J Strength Cond Res XX(X): 000-000, 2025-This study investigated the impact of substitutions on the work rate profiles of elite senior hurlers during match-play, focusing on game status and position. Global positional systems were used to collect data from 72 elite hurling players across 2 teams and 2 seasons (2022 and 2023). Players were categorized according to game status (full-game, subbed-off, subbed-on) and playing position (full-back, half-back, midfield, half-forward, full-forward). A total of 544 match samples were obtained from 30 games during the National Hurling League and Championship. Relative total, walking (≤6.9 km·hour-1), jogging (7-11.9 km·hour-1), running (12-16.9 km·hour-1), high-speed running (HSR; 17-21.9 km·hour-1), sprint (≥22.0 km·hour-1) and high-metabolic-load distance (HMLD; >25 W·kg-1), max velocity (km·hour-1), and sprints per minute (n) were analyzed. Subbed-on players outperformed both full-game and subbed-off players across multiple metrics. They covered greater relative total (ES = 0.65 and 0.40, respectively), running (ES = 0.65 and 0.37, respectively), HSR (ES = 1.05 and 0.66, respectively), sprint (ES = 0.78 and 0.33, respectively), HML distance (ES = 0.95 and 0.60, respectively), and sprints per minute (ES = 0.69 and 0.49, respectively). Subbed-on midfielders covered greater relative total (ES = 0.86), jogging (ES = 0.99), and running distance (ES = 1.13) compared with subbed-on full-forwards. These findings present key implications for substitute training, highlighting the need to expose players to full-game demands and maximum velocities within training. Additionally, playing position should also be considered when planning substitutions.

Abstract: Vasenina, E, Fukuda, DH, Livingston, JJ, Antonio, BB, Herda, AA, Mangum, LC, and Stout, JR. Sensitivity of structural and mechanical markers of muscle and tendon damage responses following eccentric plantar flexor exercise. J Strength Cond Res XX(X): 000-000, 2025-This study aimed to investigate the acute structural and functional responses of the calf musculature and Achilles tendon following an eccentric exercise-induced muscle damage (EIMD) protocol and to evaluate the sensitivity of diverse assessment tools. Twenty young, recreationally active men performed a unilateral EIMD protocol consisting of 4 × 50 heel drops plus a final set to failure wearing a weighted vest equal to 40% of body mass, while the contralateral leg served as a control. Assessments included gastrocnemius and Achilles tendon thickness and length (ultrasound), calf circumference, pressure pain threshold, isometric strength, myotonography, and global/local pain ratings. Measurements were collected at baseline and 0, 24, 48, and 72 h postexercise. Significant visit × leg interactions (p < 0.05) were observed across most markers. Gastrocnemius thickness increased by 22.4% immediately after and remained 12.9% elevated at 72 h. Achilles tendon thickness decreased by 21.7% postexercise, while tendon length increased by 12%. Isometric strength declined 15-25% at 24-48 h. Calf creep and relaxation times also decreased >15% across time points. Numerical Pain Rating Scale peaked at 48 h (mean increase of +37 points). Pressure pain threshold was significantly lower in the intervention leg at all time points (p < 0.01). Eccentric plantar flexor exercise induced significant changes in muscle-tendon structure and function. Gastrocnemius thickness, tendon morphology, strength, myotonographic properties, and pain ratings were among the most sensitive indicators. These findings highlight the value of using a multimodal battery, including ultrasound, myotonography, strength testing, and pain ratings, to comprehensively monitor recovery after eccentric exercise.