Journal of Strength and Conditioning Research最新文献

Abstract: Sánchez-Abselam, O, González-Fernández, FT, Castillo-Rodríguez, A, and Onetti-Onetti, W. External load of professional female soccer players in the competitive microcycle: Influence of playing position and contextual variables. J Strength Cond Res 40(3): e324-e332, 2026-Women's soccer has experienced substantial growth in recent years, accompanied by increased scientific interest in performance-related variables. This study aimed to analyze the external load across competitive microcycles in a professional women's soccer team and to examine the influence of playing position and contextual factors (match location, outcome, and opponent quality) on physical demands. Eighteen professional players (age: 24.5 ± 5.6 years; body mass: 58.8 ± 14.8 kg; height: 165 ± 5.7 cm) from a Spanish second-division team were monitored across 13 microcycles using 10 Hz Global Positioning System devices. Players were categorized into 5 positions: central defenders, external defenders, midfielders, wingers, and forwards. Significant differences were observed across microcycle days ( p < 0.001), with match day (MD) presenting the highest external load values, and MD-1 the lowest. Playing position significantly affected explosive distance, high-speed running, and high metabolic load distance ( p < 0.001), with forwards showing the highest values and central defenders the lowest. In addition, greater physical demands were recorded when competing against lower-ranked opponents. These findings provide relevant insights for physical performance staff, highlighting the importance of adjusting training loads based on both positional profiles and contextual factors to optimize performance and recovery strategies in elite women's soccer.

Abstract: Howard, MA, Rivera, PM, Lubiak, SM, Proppe, CE, Schmidt, JT, Rolnick, N, Shobe, ED, Fraifer, TL, and Hill, EC. Uniform neuromuscular responses across varied blood flow restriction training strategies. J Strength Cond Res 40(3): 304-310, 2026-The purpose of this investigation was to assess neuromuscular responses during acute bouts of resistance exercise with low-load blood flow restriction (LLBFR) performed with a 75-repetition protocol (75-rep; 1 × 30, 3 × 15), 3 sets to failure (3×), and 1 set to failure (1×). Seventeen recreationally active females randomly completed 75-rep, 3×, and 1× protocols consisting of unilateral, submaximal (30% of maximal voluntary isometric contraction), isokinetic (90°·s -1 ), leg extension muscle actions. A greater number of repetitions were performed during set 1 of the 1× protocol (59.5 ± 35.1) compared with the 75-rep protocol (30.0 ± 0.0), and more total repetitions were performed in the 3× protocol (85.2 ± 42.2) compared with the 1× protocol (59.5 ± 35.1). Surface electromyographic (sEMG) amplitude (AMP) progressively increased and then plateaued after 2 sets for the 75-rep protocol (118.3 ± 31.4% to 185.9 ± 85.3%; p = 0.043) and after 1 set of the 3× protocol (119.6 ± 8.6% to 206.3 ± 84.1%; p = 0.003). In addition, sEMG mean power frequency (MPF) decreased and then plateaued after 3 sets of the 75-rep protocol (99.8 ± 3.5% to 88.8 ± 11.7%; p = 0.012) and after 1 set of the 3× protocol (101.0 ± 8.2% to 84.4 ± 18.9%; p < 0.001). The changes in sEMG AMP and sEMG MPF across multiple sets (i.e., 75-rep and 3×) never exceeded the changes observed after the 1× protocol. Despite variations in set and repetition schemes, performing just 1 set of LLBFR to failure was sufficient to maximize acute neuromuscular responses. This highlights the efficiency of a single-set LLBFR protocol as a time-effective option for athletes and practitioners.

Abstract: Ocaña-García, Á, Herrero-Atiénzar, JM, López-Gullón, JM, Bonacasa, B, and Bayonas-Ruiz, A. A velocity-based approach to variable resistance training in the bench press: repetitions to failure and level of effort. J Strength Cond Res 40(3): 272-282, 2026-This study analyzed the use of elastic bands in the bench press exercise within a velocity-based training approach to explore its application in variable resistance training (VRT) in regard to the level of effort methodology. Therefore, we aimed to (a) investigate the intersubject and intrasubject variability in the number of repetitions to failure ( n RM) across 3 one-repetition maximum percentages (%1RM) and 2 load configurations using elastic bands: 25% (B25) and 50% (B50) of the load from bands; (b) examine the relationship between the number of repetitions completed and velocity loss reached; (c) assess the mean propulsive velocity associated to each %1RM and elastic bands contribution; and (d) study the influence of the subject's strength level on these parameters. After determining the individual 1RM, 26 subjects with low ( n = 9), medium ( n = 9), and high ( n = 8) relative strength levels completed 2 rounds of n RM tests against their 60, 70, and 80% 1RM with B25 and B50 configurations in the bench press. Number of repetitions to failure increased with band contribution (B50 > B25, p < 0.01) and showed moderate intersubject variability (coefficients of variation = 16%) and very low intrasubject ( SEM ≤ 1.4 repetitions) variability for all the strength levels, %1RM, and band contributions analyzed. A very high correlation ( R2 = 0.910-0.935) between the number of repetitions completed and the percentage of velocity loss reached (from 5 to 65%) was found. These findings support the use of the level of effort as a reliable and practical tool for programming VRT.

Abstract: Jakobsen, MD, Sundstrup, E, and Andersen, LL. Neuromuscular fatigue during heavy resistance drop set training to failure. J Strength Cond Res XX(X): 000-000, 2026-Training to momentary muscular fatigue is an important variable in resistance exercise planning. Current research largely focuses on muscle activity in single resistance training repetitions, leaving a gap in understanding neuromuscular fatigue over complete sessions. The purpose of this study was to determine the neuromuscular responses during a leg press drop set (DS) training bout to momentary muscular fatigue. Nineteen novice subjects (6 women, 13 men, aged 28-67) completed a DS routine involving 3 sets to muscle failure at 10-12 repetition maximum loads. Electromyographic activity from 6 leg muscles: vastus medialis (VM), vastus lateralis, rectus femoris, biceps femoris, semitendinosus, and gluteus maximus was recorded to evaluate neuromuscular fatigue indices: Normalized EMG (nEMG), Wavelet Index Ratio (WIRW51), and Median Power Frequency (MPF). Knee joint angles were measured using inclinometers. Across repetitions, nEMG increased in all muscles except VM and ST and did not differ across sets. MPF decreased with repetition in all muscles except BF and decreased across sets in all muscles except GM. WIRW51 increased within repetitions and across sets for all muscles except GM. Range of motion and contraction time declined as repetitions accumulated and were unchanged across sets. Accordingly, drop set resistance training induces significant neuromuscular fatigue across multiple muscle groups, evidenced by increased nEMG, decreased MPF, and altered WIRW51. These findings inform more targeted and effective resistance exercise programming for maximizing momentary muscular fatigue.

Abstract: Moreno-Azze, A, López-Plaza, D, Falcón-Miguel, D, and Gómez-Carmona, CD. The effects of an 8-week unilateral plyometric training program on jump performance, change of direction, and interlimb asymmetries in ice hockey players. J Strength Cond Res XX(X): 000-000, 2025-This study aimed to investigate the effects of an 8-week unilateral plyometric training program on lower limb performance, interlimb asymmetries, and change-of-direction (COD) abilities in male and female ice hockey players. Twenty-nine ice hockey players (15 men, 14 women) were first divided by sex and then assigned to experimental (EG) and control (CG) groups. The EG underwent a unilateral plyometric training program apart from their regular training, while the CG maintained only their regular training. Functional performance tests, including single-leg hop (SH), triple hop (TH), countermovement jump (CMJ), and COD tests on both track and ice surfaces, were conducted preintervention and postintervention. The EG showed significant improvements in jump performance and COD, with reductions in interlimb asymmetries. In particular, women of the EG demonstrated significant gains in SH (stronger leg: effect size [ES] = 1.20, p < 0.01; weaker leg: ES = 1.12, p < 0.01) and TH (stronger leg: ES = 1.18, p < 0.01; weaker leg: ES = 0.82, p = 0.02), while men improved in CMJ (stronger leg: ES = 0.54, p = 0.02), SH (stronger leg: ES = 1.42, p < 0.01; weaker leg: ES =1.26, p < 0.01), and COD (stronger leg: ES = 0.78, p = 0.05; weaker leg: ES = 0.69, p = 0.02). Asymmetry reductions were notable in SH for women (ES = -0.50, p < 0.01) and COD for men (ES = -0.76, p = 0.01). Unilateral plyometric training effectively enhances lower limb performance and reduces interlimb asymmetries in ice hockey players, with sex-specific adaptations.

Abstract: Brassington, RJ, Mara, JK, Ball, NB, Waddington, G, Paul, K, and Cooke, J. Does playing level and position influence strength and power profiles in female rugby league athletes? J Strength Cond Res XX(X): 000-000, 2025-The purpose of this study was to compare the physical characteristics and physical qualities of elite and subelite female rugby league athletes, with a focus on strength, power, and positional differences between forwards and backs. Fifty-one female athletes participated (subelite: n = 26, height: 167.1 ± 6.0 cm, mass: 69.1 ± 10.7 kg, age: 17.4 ± 0.5 years; elite: n = 25, height: 167.5 ± 6.3 cm, mass: 78.3 ± 12.6 kg, age: 23.6 ± 4.3 years). Assessments included anthropometry, 3-repetition maximum (3RM) trap bar deadlift (TBD), 3RM bench press (BP), countermovement jump (CMJ), squat jump (SJ), and drop jump (DJ) tests using dual force plates. Elite athletes demonstrated significantly greater maximal strength in the TBD (B = 39.84 kg [19.97, 59.72], p < 0.001, ES = 1.75) and BP (B = 9.13 kg [-0.14, 18.41], p = 0.053, ES = 1.33). In the CMJ, elite players recorded greater peak power (B = 571.04 W [230.76, 911.33], p = 0.002, ES = 1.00) and longer eccentric and concentric durations (B = 43.37 ms [20.53, 66.22], p < 0.001, ES = 1.62), reflecting distinct movement strategies. They also produced higher SJ jump height (B = 3.89 cm [0.98, 6.79], p = 0.01, ES = 1.36), peak power (B = 670.74 W [349.31, 992.16], p < 0.001, ES = 1.62), and concentric impulse (B = 33.66 N·s [17.76, 49.56], p < 0.001, ES = 1.71). Drop jump results showed fewer differences, with level effects limited to concentric impulse (B = 34.01 N·s [13.78, 54.22], p = 0.002, ES = 1.29). Positional effects indicated forwards were heavier (B = 9.10 kg [0.03, 18.2], p = 0.049, ES = 1.02) and produced greater SJ take-off force (B = 240.80 N [20.18, 461.43], p = 0.033, ES = 1.05). Elite female rugby league athletes display superior maximal strength, lower-body power, and distinct jump strategies compared with subelite players. These characteristics likely underpin the increased physical demands of elite competition. Strength and conditioning programs for subelite athletes should emphasize maximal strength, concentric impulse, and eccentric control, with position-specific emphasis on collision strength for forwards and reactive strength for backs.

Abstract: Talpey, SW, Haintz, L, Drake, M, Mundy, PM, Rayner, R, James, LP, O'Grady, M, Gabbett, TJ, and Gardner, EC. The utility of the countermovement rebound jump for the assessment of neuromuscular status in National Collegiate Athletic Association Division I American football players. J Strength Cond Res XX(X): 000-000, 2025-The purpose of this study was to explore the sensitivity of the countermovement rebound jump (CMRJ) for assessing neuromuscular status after National Collegiate Athletic Association (NCAA) Division I American Football games. Twenty-nine male NCAA Division I American football players completed CMJ and CMRJ assessments 24 hours pregame, and at 24 and 72 hours postgame across 2 competitive matches. Jump testing was performed using dual force plates, and total PlayerLoad was recorded during games via Global Positioning System tracking. Linear mixed-effects models were used to examine the effects of time, match load, and game on CMRJ and CMJ metrics. Significant findings were followed by post-hoc pairwise comparisons and calculation of effect sizes. Significant time-dependent decrements were observed in CMRJ average power (p = 0.001, d = 0.67), RSImod (p = 0.03, d = 0.49), and jump height (p = 0.046, d = 0.46) at 24 hours postmatch, with recovery evident in average (p = 0.002, d = -0.63) and peak power (p = 0.004, d = -0.60) by 72 hours. Countermovement jump height increased significantly by 72 hours (p = 0.02, d = -0.49). Match load significantly mediated recovery trajectories for CMJ RSImod (p = 0.004) and time to take-off (p = 0.016), with higher loads associated with impaired recovery. The CMRJ appears to be more sensitive to acute fatigue. Whereas certain CMJ metrics were more sensitive to detecting how recovery trajectories were moderated by game load. The CMRJ offers practitioners a time-efficient and informative tool to assess the presence of acute fatigue after competition.

Abstract: Cusimano, K, Moran, DJ, Tod, DD, and Freeman, DP. The effects of psyching-up on deadlift performance in competitive strongmen, strongwomen, and powerlifters. J Strength Cond Res XX(X): 000-000, 2026-This study investigated the effect of the act of "psyching-up" on deadlift performance in experienced strength athletes and examined whether individual differences in anxiety sensitivity, reward sensitivity, and trait aggression influence strategy selection. A total of 200 competitive strength athletes completed the Behavioral Inhibition System/Behavioral Activation System Likert scale and the Buss-Perry Aggression Questionnaire. Subjects then performed a deadlift under 2 conditions: a free-choice psyching-up intervention and a passive control. Barbell velocity was measured using a GymAware RS linear position transducer. Results showed that deadlift velocity was significantly greater during the psyching-up condition (M = 0.39 m·s-1, SD = 0.11) compared with the control (M = 0.34 m·s-1, SD = 0.10), representing an 18.58% increase in performance (p < 0.001). This improvement in bar speed corresponds to an estimated 4.3% increase in predicted 1-repetition maximum. A one-way ANOVA found no significant differences in performance across the 8 psyching-up strategies (p = 0.16). However, discriminant analysis revealed that higher reward sensitivity, greater trait aggression, and lower anxiety sensitivity significantly predicted the selection of "arousal-enhancing" strategies (p = 0.002). These findings indicate that psyching-up can support deadlift performance in strength athletes and that personality traits may influence their choice of strategy. While no single strategy was found to be more effective than others, the data suggest that athletes tend to select strategies that reflect their individual personality traits. This study also presents a discriminant function that may help practitioners and coaches recommend appropriate psyching-up approaches based on an athlete's personality profile, contributing to more effective and individualized psychological preparation in strength sports.

Abstract: Palanisamy, AC, Ahluwalia, J, Bahrami, B, Randhawa, A, and Kobsar, D. Beyond jump height: The value of phase-specific metrics for monitoring fatigue in basketball. J Strength Cond Res XX(X): 000-000, 2026-Basketball athletes must balance intense training demands with recovery to maintain peak performance, while minimizing fatigue-related injuries. Assessing the acute effects of basketball practice on countermovement jump (CMJ) metrics offers a valuable approach to evaluating the impact of practice volume on neuromuscular performance. Fourteen male athletes from the McMaster University basketball team participated in this study, with data collected pre- and postpractice for a 10-week period. Results revealed significant decreases in performance output metrics, such as jump height and modified reactive strength index, after practice. In addition, phase-specific temporal metrics, including braking phase duration, increased, whereas driver metrics, such as eccentric mean braking force and eccentric rate of force development, decreased, indicating altered neuromuscular strategies due to fatigue. However, these changes had limited associations to practice volume measured by inertial sensors, suggesting substantial individual variability in fatigue responses. These findings demonstrate the sensitivity of CMJ metrics to acute fatigue, particularly phase-specific force-time components, providing deeper insights into neuromuscular adaptations beyond performance output alone. Although CMJ metrics effectively capture fatigue-related changes, the magnitude of these changes does not exhibit a clear relationship with practice load, highlighting the complexity of monitoring fatigue responses in team sports. This study enhances the understanding of player fatigue and underscores the practical application of force plate technology in sports science to inform individualized training and recovery strategies.

Abstract: Maestroni, L, Turner, A, Read, P, Bettariga, F, Fenu, G, Rosalia, A, Guastella, M, and Bishop, C. Inter-limb asymmetry data in athletes with anterior cruciate ligament reconstruction: A comparison of different equations to interpret between-limb difference data. J Strength Cond Res 40(2): 158-166, 2026-Between-limb performance and biomechanical differences (i.e., interlimb asymmetries) after anterior cruciate ligament (ACL) reconstruction are monitored and reported during rehabilitation and at the time of return to sport. However, different asymmetry equations can alter the magnitude and consistency of the asymmetry. Fifty-three amateur athletes (16 women; 37 men; 28.5 ± 6.7 years; 177.1 ± 6.5 cm; 75.3 ± 10.8 kg) at a median of 28.1 months post-ACL reconstruction completed a strength and vertical jump assessment including 5 repetition maximum (RM) box squat, rear foot elevated split squats, leg extension and countermovement jump (CMJ), single-leg CMJ, and single-leg drop jump. Large significant differences (ƞ 2 = 0.14-0.44) were found between unilateral equations for each variable assessed, and between bilateral equations (ƞ 2 = 0.17-0.34) for CMJ concentric and eccentric impulse asymmetries. Small to large significant pairwise differences were present between each equation and variable in unilateral tasks ( d = 0.46-2.30). For the CMJ, large significant pairwise differences were also found between most equations for CMJ concentric and eccentric impulse asymmetry ( d = 0.99-3.04). We recommend the use of the Standard Percentage Difference (with direction) formula for unilateral tasks and the Bilateral Asymmetry Index 1 for bilateral tasks.