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 XX(X): 000-000, 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: 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: Rostami, M, Lee, A, Frazer, AK, Akalu, Y, Tallent, J, Walker, S, and Kidgell DJ. Strength training preferentially enhances corticospinal output compared to high-intensity interval training. J Strength Cond Res XX(X): 000-000, 2026-Corticospinal responses to motor training are influenced by the specific task, muscle group involved, and contraction type. Yet, the distinct effects of high-intensity interval training (HIIT) and strength exercise (SE) on corticospinal excitability and inhibition remain unclear. Although most studies focus on upper-limb muscles not directly engaged in HIIT, this study investigated corticospinal, intracortical, and spinal responses in lower-limb muscles actively involved in both exercises. Eighteen healthy untrained subjects completed a 20-minute high-intensity interval cycling task (HIIT), a single bout of high-intensity SE, and a no-exercise control session on separate days. Corticospinal, intracortical, and spinal responses were assessed using transcranial magnetic stimulation (TMS) and peripheral nerve stimulation at baseline and 5 minutes postexercise. Compared with control, both HIIT and SE significantly increased motor-evoked potential (MEP) amplitude at 130% active motor threshold (AMT) (HIIT: p = 0.006; SE: p < 0.001), with SE inducing substantially greater increases than HIIT (p < 0.001). At 150% AMT, only SE significantly increased MEP amplitude compared with baseline, control, and HIIT (p < 0.001). Silent period duration was significantly reduced following SE at 130% AMT (p = 0.004) and following both HIIT (p = 0.03) and SE (p = 0.04) at 150% AMT. Only SE led to significant reduction in short-interval intracortical inhibition (p = 0.02). Spinal excitability remained unchanged. These findings highlight task-dependent corticospinal plasticity in lower-limb muscles and suggest that SE may be particularly effective for enhancing acute corticospinal excitability, with potential implications for neurorehabilitation programs targeting conditions associated with reduced corticospinal excitability.

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: Calaway, C, Elkins, E, Gastaldo, R, Sarama, J, Sands, R, Lamorta, R, Conn, M, and Signorile, JF. The influence of visual feedback on neuromuscular performance during resistance training in healthy older adults. J Strength Cond Res XX(X): 000-000, 2026-Visual feedback (VF) has shown to significantly improve strength, movement speed, and levels of motivation in athletic populations. To our knowledge, no study has examined the impact of graphical power feedback on lower- and upper-limb neuromuscular performance in healthy older adults. To determine the impact of live VF compared with that of no feedback (NoVF) on leg-press (LP) and chest-press (CP) peak power (PP) and average power (AP) using HUR (HUR Inc, Park Ridge, IL) pneumatic resistance training machines, 28 older adults (73.1 ± 6.7 years) completed 2 training sessions per week for 2 weeks separated by at least 48 hours of rest. In session 1, subjects were provided VF on the HUR tablets. During session 2, subjects were not provided with VF. Both groups completed 3 × 8 repetitions on each machine separated by 1-minute rests. Separate 2 × 2 × 3 (condition × week × set) repeated measures ANOVAs revealed condition, week, and set effects for LP-PP (p < 0.05) showing greater power with VF (MDiff ± SE = 23.8 ± 6.8 W, +4%) and across weeks and sets. For CP-PP, a condition effect was seen (p < 0.05), indicating greater VF performance (20.9 ± 9.7 W, +5%). Leg-press-average power and chest-press-average power both showed significance for all main effects (p < 0.05), showing greater performance with VF (25.6-25.8 W, +4-5%) and across weeks and sets; however, power only increased from sets 1-3 for CP-AP. Graphical VF is a viable tool for optimizing neuromuscular performance in older adults. Furthermore, greater power outputs in the subsequent LP sets for both PP and AP suggest a level of neuromuscular facilitation in the lower limbs, which warrants sufficient warm-up to maximize power during training.

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.

Abstract: Iglesias-Soler, E, Fariñas, J, Rúa-Alonso, M, Rial-Vázquez, J, Nine, I, and Revuelta-Lera, B. Shorter set configurations attenuate performance loss and lactatemia during resistance training in postmenopausal women: A randomized crossover trial (CARE project). J Strength Cond Res 40(2): e180-e188, 2026-Menopause is a stage of life associated with a decline in muscle mass and strength, which underscores the importance of resistance training (RT) for preserving neuromuscular function in women. This study analyzed the effect of set configuration (SC) in RT sessions on lactatemia, mechanical performance, and neuromuscular fatigue in postmenopausal women. Fifty physically active postmenopausal women performed, in randomized order, 3 resistance sessions consisting of 4 exercises: leg press (LP), bench press (BP), prone leg curl, and lateral pull-down. The sessions were matched for load intensity (12 repetition maximum), volume (36 repetitions per exercise), and work-to-rest ratio, but differed in SC: 9 sets of 4 repetitions (4S), 6 sets of 6 repetitions (6S), and 4 sets of 9 repetitions (9S). A linear velocity transducer recorded concentric velocity and power in each repetition of LP and BP. Intraset and session-level velocity loss and power loss were calculated. Lactatemia and explosive performance in LP and BP were assessed before and after each session. Data were analyzed using linear mixed models. 4S improved mechanical performance and attenuated intraset and session velocity loss and power loss, while eliciting smaller increases in lactatemia than other configurations. Within each configuration, velocity and power loss were significantly higher in BP than in LP. Similar reductions in explosive performance were observed across all sessions. In conclusion, SC modulates both mechanical performance and glycolytic involvement in postmenopausal women. Exercise-specific differences highlight the need for caution when using fixed velocity- and power-loss thresholds to estimate effort in this population.

Abstract: Li, J, Chen, Z, Xu, K, Wang, Y, and Gong, M. Comparison of variable resistance and free weight training on long-term and acute effects on different assessments of strength: a systematic review and meta-analysis. J Strength Cond Res 40(2): e211-e223, 2026-Variable resistance training (VRT) addresses biomechanical disadvantages of free weight training (FWT), but its long-term and acute effects on strength remain underexplored. This study aimed to compare the effects of VRT and FWT on the following variables-maximal strength, velocity, power output, and jump distance-under both long-term and acute interventions. The study used cluster analysis to define variable resistance load proportion (VRLP) groups. Pairwise meta-analysis assessed long-term outcomes, subgroup analyses by VRLP, VRT equipment (elastic bands or chains), and number of VRT exercises (single or multiple). Acute interventions were evaluated using network meta-analysis across VRLP and FWT groups. Effect sizes were reported as standardized mean differences (SMD). For long-term effects, VRT outperformed FWT in maximal strength (repetition maximum or force output) and jump distance (vertical or horizontal) (0.28 ≤ SMD ≤ 0.37). Specifically, chain-based loading and VRLP ≤20% showed advantages across both outcomes (0.39 ≤ SMD ≤ 0.51). Multiple-exercise VRT improved maximal strength (SMD = 0.27), whereas single-exercise VRT improved jump distance (SMD = 0.46). For acute effects, VRLP >20% showed superior maximal strength (force output) (0.46 ≤ SMD ≤ 0.79), VRLP >37% resulted in lower maximal velocity (movement velocity) and power output (SMD ≤ -1.31) compared with FWT. Thus, long-term VRT surpasses FWT in maximal strength and jump distance, with chain-based or VRLP ≤20% of VRT optimal; multiple exercises benefit maximal strength, and single exercise improves maximal jump distance. Acutely, VRLP of 21-37% VRT results in greater mechanical output in a variety of exercises.

Abstract: Naclerio, F, Larumbe-Zabala, E, Chapman, M, Gonzalez-Frutos, P, and Triplett, NT. Comparable workout output by using velocity feedback or perceived exertion in male and female recreationally resistance trained individuals. J Strength Cond Res 40(2): 143-151, 2026-We compared an objective (velocity feedback [VEL]) vs. a subjective (rating of perceived exertion [RPE]) autoregulatory method to estimate velocity drop thresholds associated with low (10%), moderate (20%) metabolic fatigue, and muscular endurance (40%) during continuous sets in the back squat (BSQ) exercise using either 50% or 75% of the 1 repetition maximum (1RM). After five sessions of familiarization and determining the 1RM, 19 male subjects (24.5 ± 6 years) and 9 female subjects (30.4 ± 8 years) underwent two identical 6-day testing sessions over 2 weeks (12 sessions) using the VEL (first 6 sessions) or the RPE method (last 6 sessions). The assessments of velocity thresholds and relative loads were randomized for each 6-day testing period. The average velocity (AV) and the OMNI-RES (0-10) scale scores were measured for every repetition of each set. Under VEL, sets ended after completing two consecutive repetitions below the target threshold. A linear mixed-effects model setting velocity thresholds, method, and their interaction as fixed effects, and subjects as random components, was conducted. Although no significant differences between methods were identified for the percentage of velocity decrease and the total number of repetitions completed per set, compared with VEL, under the RPE method, fewer repetitions were completed below the thresholds for both 50 and 75% 1RM ( p < 0.01 and g > 1 in all cases). In conclusion, both methods, VEL and RPE, seem useful for estimating velocity changes during continuous sets of BSQ. However, the RPE method allowed for fewer unnecessary repetitions when squatting until 10, 20, and 40% of velocity decrease.