Journal of Strength and Conditioning Research最新文献

Abstract: Buechel, CM, Pumpa, KL, Etxebarria, N, and Minehan, M. Expert consensus on weight management strategies for strength and physique athletes before and after competition. J Strength Cond Res 40(2): e155-e163, 2026-Strength and physique athletes undergo repeated cycles of weight loss and weight gain to optimize body composition for competition, often experiencing periods of low-energy availability and related health and performance risks. Postcompetition recovery strategies remain poorly understood. This study aims to achieve expert consensus on dietary recommendations for weight management strategies in the context of requiring weight loss for competition and weight restoration afterward. Fifteen international bodybuilding and powerlifting experts, including coaches and dietitians, participated in a 3-round Delphi survey. Round 1 collected responses to open-ended questions relating to weight management around competition periods. Responses were thematically analyzed into 85 statements and recirculated for round 2 where subjects rated their level of agreement with each statement. Round 3 consisted of revised statements that had previously failed consensus (30 revised and 11 new). Agreement was reached on 75 statements total (consensus threshold of ≥70%) relating to individualized weight management strategies, weight loss methods, and peaking protocols. The 21 statements that failed to reach consensus pertained to refeeding strategies for postcompetition recovery. Experts emphasized structured refeeding approaches, with most agreeing that bodybuilders require 1-6 months for physiologic recovery and a 10-15% body weight regain. Reverse dieting was not favored, with experts recommending an initial acute energy increase followed by a gradual rate of gain. Powerlifters required less restrictive postcompetition dietary recovery strategies, with most returning to off-season training within 1-2 weeks. Findings highlight the importance of athlete education, individualized weight management strategies, and structured recovery planning.

Abstract: Nguyen, AP, Kisita, V, Van Cant, J, Monnet, T, and Bosquet, L. Reproducibility of rate of perceived exertion-based self-selected running speeds on indoor track and treadmill conditions in recreational runners. J Strength Cond Res 40(2): e125-e130, 2026-This study evaluates the reproducibility of self-selected speeds at a rate of perceived exertion (RPE) of 3/10 in both track and treadmill conditions. It also investigates the differences between 2 conditions: i.e., track versus treadmill and 2 RPE instructions, i.e., 3/10 and 8/10. In addition, it compares spatiotemporal parameters across conditions and RPE levels. Fifty-five recreational runners completed six 1-km runs under randomized conditions: 4 at 3/10 and 2 at 8/10 RPE on both track and treadmill. Spatiotemporal parameters, heart rate, and self-selected speeds were recorded. Reliability was assessed using intraclass correlation coefficients (ICC), standard error of measurement ( SEM ), and minimal detectable change (MDC). Statistical significance for all tests was set at α = 0.05. Self-selected speeds showed excellent reliability on both surfaces (ICC = 0.93-0.97). The track showed lower SEM (0.3 km·h -1 ) and MDC (0.7 km·h -1 ) values compared with the treadmill ( SEM : 0.6 km·h -1 ; MDC: 1.6 km·h -1 ). Speeds were 20% slower at 3/10 RPE and 10% slower at 8/10 RPE on the treadmill. Treadmill running exhibited longer contact times (+13%), shorter flight times (-35%), and shorter step lengths (-6%) at 3/10 RPE, with similar trends observed at 8/10 RPE. Rate of perceived exertion appears to be a reliable and practical tool for monitoring and prescribing running intensity levels. The slower treadmill speeds at comparable RPE levels may help reduce biomechanical loading on the lower limb joints, offering advantages for rehabilitation. However, differences in biomechanics and perceived effort between treadmill and track running highlight the need for context-specific applications in training and rehabilitation.

Abstract: Lockie, RG, Beitzel, MM, Orr, RM, Dawes, JJ, and Dulla, JM. A Preliminary analysis of self-efficacy relationships with general and job-specific fitness in law enforcement officers. J Strength Cond Res 40(2): e197-e201, 2026-General and job-specific fitness may decline in law enforcement officers during their careers. Exercise self-efficacy (individual's belief in ability to perform exercise) may present as one reason why an officer's fitness declines and could relate to the officer's general and job-specific fitness. Archival data from 60 officers (48 men, 12 women) were analyzed. A 6-item questionnaire measured coping (ability to adapt) and scheduling (ability to manage and schedule) self-efficacy. The items were assessed on a scale of 0 (not confident) to 100 (completely confident). General fitness tests included resting heart rate, blood pressure, skeletal muscle mass and fat mass percentage (FM%), waist-to-hip ratio (WHR), sit-and-reach, grip strength, 60-s push-ups, 60-s sit-ups, and YMCA step test recovery heart rate. Job-specific fitness was measured by a 99-yard obstacle course (99OC), body drag, 6-foot chain link fence climb (CLF), 6-foot solid wall climb (SW), and 500-yard run. Partial correlations controlling for sex and age calculated relationships between self-efficacy with fitness ( p < 0.05). Coping self-efficacy had small-to-moderate negative relationships with FM%, WHR, 99OC, CLF, and SW ( p ≤ 0.047). Both coping and scheduling self-efficacy had small-to-large positive relationships with push-ups and sit-ups ( p ≤ 0.040). Higher confidence in the ability to overcome exercise participation challenges related to lower BF% and WHR, and faster 99OC, CLF, and SW performance in officers. Officers confident in their ability to overcome exercise participation challenges and schedule exercise performed more push-ups and sit-ups. Providing strategies for officers to overcome challenges and manage their exercise schedules could benefit body adiposity, muscular endurance, and select job tasks.

Abstract: Škorik, M, Švantner, R, Brűnn, D, and Karabin, L. The relationship between standing broad jump and 30-meter sprint in 826 youth soccer players: a cross-sectional study. J Strength Cond Res XX(X): 000-000, 2026-Speed and acceleration are essential for offensive and defensive actions in soccer. Given the high cost of advanced sprint measurement systems, alternative field tests such as the standing broad jump (SBJ) may serve as cost-effective tools for assessing horizontal force production. However, the relationship between SBJ and sprint performance across different acceleration phases in youth players remains unclear. This cross-sectional study investigated the relationship between a no-countermovement SBJ and sprint parameters in 826 elite male youth soccer players (U14-U19). Sprint performance was assessed using the 1080 Motion Sprint system, capturing maximum velocity (Vmax), theoretical maximum velocity (V0), maximum horizontal force (F0), maximum power, and maximum ratio of force (RFmax). Average speed (AS) and average force (AF) were analyzed across 3-meter segments for a 30-meter sprint. Pearson's correlation and linear regression were used, with significance set at p ≤ 0.05. Standing broad jump showed strong correlations with sprint parameters, particularly Vmax, V0, and RFmax (r = 0.68, 0.63, and 0.58; all p < 0.001). The strongest associations between SBJ and AS or AF occurred in the late acceleration phase (9-12 m) across all age groups (AS: r = 0.75; AF: r = 0.66), with the highest correlations in U14 and U15. Regression models revealed that SBJ explained 39.1% of Vmax variance in U14, but only 9.8% in U19. These findings suggest SBJ is a practical and valid tool for evaluating sprint performance in younger players, although its predictive value declines with age because of greater influence of technical and biomechanical sprint factors.

Abstract: Lisboa, F, Gomes, F, Kunevalik, G, Manske, I, Santos, V, Prado, A, Cavalcanti, A, Tricoli, I, Costa, B, Kassiano, W, Stavinski, N, Francsuel, J, and Cyrino, ES. Ankle position-dependent muscle swelling during seated leg curl: ultrasonographic insights into the hamstrings and medial and lateral gastrocnemius. J Strength Cond Res XX(X): 000-000, 2026-The seated leg curl is one of the most prescribed exercises in hamstring strength training. Although it is a monoarticular exercise, changing the position of the ankle may influence the engagement of the muscles involved during the exercise (i.e., hamstrings and gastrocnemius muscles). We compared the lateral gastrocnemius (LG), medial gastrocnemius, and hamstrings (HT) during the seated leg curl exercise with the ankle in a neutral ankle position (NAP), plantar flexion position (PFP), and a control condition (CON), in which subjects did not perform any exercise and instead remained at rest for a duration equivalent to the exercise sessions. Each condition was performed on a different day, once per week. Muscle swelling was measured immediately after exercise and at the corresponding time point in the control condition. Seventeen young women (18-37 years) performed the experimental protocols and control condition in a crossover and counterbalanced design. In the experimental conditions, subjects performed a specific warm-up with 50% of the initial load for the exercise, completing 12 repetitions, followed by 3 sets to concentric failure, with a 2-minute interval between sets in the following conditions: NAP and PFP. The primary outcome showed that NAP resulted in greater swelling in LG compared with the CON (mean difference = 0.05 cm; 95% CI: 0.004-0.11; ES = 0.6) and with PFP (mean difference = 0.07 cm; 95% CI: 0.009-0.14; ES = 0.6). For HT, swelling was greater in NAP compared with CON (mean difference = 0.18 cm; 95% CI: 0.08-0.2; ES = 1.1) and in PFP compared with CON (mean difference = 0.14 cm; 95% CI: 0.02-0.2; ES = 0.9), but no significant difference was found between NAP and PFP (mean difference = 0.03 cm; 95% CI: -0.16 to 0.24; ES = 0.2). Our findings suggest that in the NAP condition, there is muscle swelling in both the LG and HT, whereas in the PFP condition, muscle swelling is observed only in the HT.

Abstract: Olthof, SBH, Ferrandis, J, de Dios, V, and Riboli, A. Pitch size, player numbers, and playing rules: how small-sided game constraints shape the training demands in male academy soccer. J Strength Cond Res XX(X): 000-000, 2026-Small-sided games (SSGs) are part of daily soccer practice and usually manipulated in pitch size, player number, and playing rules. The aim of this study was to identify constraints that significantly affect the physical demands in SSGs in youth elite soccer players. Training sessions from an under-18 Spanish academy team were monitored, including 87 SSGs. Small-sided games were labelled for area per player (ApP), number of players, type of game, playing duration, goal size, use of floater players and goalkeepers, and number of touches. Relative physical demands were measured as total distance (TD), high-speed running (HSR), sprint distance (SD), and acceleration (ACC) and deceleration (DEC) distance. A linear mixed-effects model analysis was performed estimating the effects of SSG constraints (α set at 0.05). Greater ApP consistently increased TD, HSR, SD, ACC, and DEC. By contrast, increasing the number of players and longer playing duration reduced TD, HSR, ACC, and DEC. In addition, specific playing rules, such as the use of floater players, limited touches, and small goals primarily affected ACC and DEC. These findings highlight the important role of ApPs in shaping physical demands, while also showing that team size, playing duration, and specific playing rules contribute to the physical demands of SSGs. Understanding the magnitude and direction of these manipulations allows coaches to design SSGs more effectively to meet training objectives.

Abstract: Koyama, K and Hosono, S. Comparison of the effects of barefoot and shod training on foot structure, muscle strength, and sensory function. J Strength Cond Res XX(X): 000-000, 2026-The aim of this study was to compare the effects of 8 weeks multicomponent lower-limb training under barefoot versus shod conditions on foot muscle strength, structure, and sensory function. Healthy adults were assigned to either a barefoot training (BARE; n = 11), shod training (SHOD; n = 11), or control (CON; n = 15) groups. BARE and SHOD completed 2 weekly training including agility, balance, and strength exercises. Measurements were taken at baseline and weeks 2, 4, 6, and 8. Outcome measures included toe flexor strength, foot arch height, and foot sensory threshold. Relative toe flexor strength increased at weeks 4, 6, and 8 in both BARE and SHOD compared with baseline and was higher than in CON. For standing relative toe flexor strength, BARE showed greater values at weeks 6 and 8 than at weeks 2, and the value at week 6 was greater than at week 4, whereas in SHOD, only values at week 8 were greater than values at week 2. In contrast, arch-related variables and foot sensory threshold showed no significant changes during most of the training period in either group, and between-group differences were generally not significant. In CON, no significant changes were observed in nearly all outcome measures from baseline to week 8. Throughout the training period, no significant differences were found between BARE and SHOD in nearly all outcome measures. Overall, compared with shod training, 8 weeks of barefoot multicomponent exercises led to continued improvement in standing toe flexor strength without changing foot structure and sensory function.

Abstract: Centorbi, M, Medoro, A, Modolo, L, Di Claudio, G, Di Martino, G, Della Valle, C, Buonsenso, A, Marziliano, N, Davinelli, S, Calcagno, G, di Cagno, A, and Fiorilli, G. Reactive training in enhancing technical performance and modulating cortisol biomarkers in competitive soccer players. J Strength Cond Res XX(X): 000-000, 2026-In soccer, the ability to perceive, process, and integrate external and internal stimuli is crucial for the development of players' technical, physical, and tactical skills. This study aimed to assess the effectiveness of an Experimental Warm-Up (EWU) protocol for enhancing soccer-specific technical and physical skills while optimizing cortisol levels in elite soccer players. Thirty-two male soccer players (age: 24.7 ± 3.1 years) from 2 elite teams were assigned to an experimental group (EG; n = 18) or a control group (CG; n = 14). During the 12 weeks, along with their regular warm-up (WU), the EG performed an EWU consisting of 4 progressive coordination exercises, 4 times per week. The CG maintained their usual WU schedule. Technical abilities were assessed pre- and postintervention using the Y-Planned and Y-React, React Index (Y-REACT minus Y-PLAN), Illinois Change of Direction with and without ball (ICODT-BALL and ICODT), Technical Index (ICODT-BALL minus ICODT), and Loughborough Soccer Shooting (SHOT) tests. Urine samples were collected before and after the 12-week intervention to measure cortisol levels. The RM-ANOVA revealed significant improvements from pre- to postassessment in the EG for the ICODT-BALL, Technical Index, Y-REACT, React Index, and SHOT (p < 0.001). These improvements were significantly greater than those in the CG. In addition, the EG showed a significant reduction in cortisol levels from pre- to postintervention (p = 0.0007) and compared with the CG (p = 0.003). These findings indicate that incorporating coordinative training into WU improves technical performance and agility in soccer, supporting better regulation of cortisol levels in elite players.

Abstract: Martin, JR, Abel, MG, Newman, K, Fyock-Martin, M, and Clark, NC. Muscle and anaerobic performance relationships with firefighter occupational tasks: A systematic review and meta-analysis. J Strength Cond Res XX(X): 000-000, 2026-Firefighting requires performing a variety of physically demanding occupational tasks. Subsequently, understanding physical fitness correlates for occupational performance tests (OPTs) is crucial for optimizing firefighter training and readiness. The purpose of this review was to examine the relationship between muscle and anaerobic performance measures with the completion of firefighting OPTs. The review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and included studies with firefighters and reporting relationships between measures of muscle and anaerobic performance with OPT outcomes. Random effects models were used to calculate pooled correlation coefficients. Thirty-two studies were included and assessed muscle and/or anaerobic performance using varied assessment protocols and OPTs that simulated firefighting tasks such as stair climb, equipment carry, ladder raise, victim drag, and forcible entry. The pooled correlations for time to complete OPTs consisting of circuits of firefighting tasks ranked from strongest to weakest were anaerobic capacity, anaerobic power, lower body strength, upper body strength, upper body endurance, lower body endurance, and core endurance. For single firefighting task OPTs, pooled correlations indicated muscle and anaerobic performance had varied associations with OPT completion time, dependent on task-specific biomechanical and physiologic demands. The cumulative findings highlight the importance of muscle and anaerobic fitness for performing firefighting task OPTs. A physical fitness assessment for firefighters could include the isometric mid-thigh pull, handgrip, maximum push-ups, and either a Wingate test or 400-meter sprint. Results from these assessments can guide training programs to meet entry requirements, maintain readiness, and support postinjury return to duty.