J Strength Cond Res [JOURNAL]
Sun
200 papers
The Determinants of Deceleration and Reacceleration Abilities in Pro-Agility Test in Adolescent Soccer Players.
Nakamura H, Yamashita D, Nishiumi D … +2 more , Nakaichi N, Hirose N
J Strength Cond Res · 2026 Apr · PMID 41874530 · Publisher ↗
Nakamura, H, Yamashita, D, Nishiumi, D, Nakaichi, N, and Hirose, N. The determinants of deceleration and reacceleration abilities in pro-agility test in adolescent soccer players. J Strength Cond Res 40(4): 439-450, 2026...
Nakamura, H, Yamashita, D, Nishiumi, D, Nakaichi, N, and Hirose, N. The determinants of deceleration and reacceleration abilities in pro-agility test in adolescent soccer players. J Strength Cond Res 40(4): 439-450, 2026-This study investigated how deceleration and reacceleration abilities in a Pro-Agility test are influenced by kinematic, physical, and maturation factors in male adolescent soccer players. Seventy-one soccer players performed jump tests (standing long jump, countermovement jump, squat jump) and a Pro-Agility test. Kinetic variables during countermovement and squat jumps were obtained using dual force plates, and 3-dimensional kinematic data from the Pro-Agility test were obtained using a markerless motion capture system. In the Pro-Agility test, the deceleration and acceleration phases were determined from the center-of-mass (COM) velocity and subdivided into early and late halves. The mean COM deceleration (Dec) and acceleration (Acc) were calculated in each phase and event. A linear mixed model was used to identify the variables predicting Dec and Acc. Statistical significance was set at p < 0.05. Both first late Dec and second late Dec were associated with Dec during penultimate foot contact (β = 0.231 and β = 0.197, respectively) and COM height at the final foot contact (β = 5.431 and β = 2.910, respectively). Both second early Acc and third early Acc were associated with peak propulsive force in squat jump (β = 0.050 and β = 0.086, respectively). Second early Acc was associated with body height (β = 0.086), and third early Acc was associated with chronological age (β = 0.086), but not with deceleration abilities. These findings highlight the importance of tailoring training strategies to enhance overall change-of-direction performance.
Definition of Substantial Athletic Benefit and Satisfaction of a Neuromuscular and Strength Training Program for Ballet Dancers.
Crampton CT, Smith ST, Noyes FR
J Strength Cond Res · 2026 Jun · PMID 41870301 · Publisher ↗
Crampton, CT, Smith, ST, and Noyes, FR. Definition of substantial athletic benefit and satisfaction of a neuromuscular and strength training program for ballet dancers. J Strength Cond Res 40(6): e629-e638, 2026-The aim...
Crampton, CT, Smith, ST, and Noyes, FR. Definition of substantial athletic benefit and satisfaction of a neuromuscular and strength training program for ballet dancers. J Strength Cond Res 40(6): e629-e638, 2026-The aim of this prospective cross-sectional study was to assess the psychometrics and performance outcomes on preprofessional ballet dancers undergoing a neuromuscular and strength training program. We hypothesized that ballet dancers would perceive substantial benefits of this training program and significantly improve performance outcomes. Twenty-eight dancers from a preprofessional ballet training program volunteered to participate in a 6-week neuromuscular and strength training program. The dancers completed a psychometric questionnaire and objective testing before and after the training program. The psychometric questionnaire evaluated individual substantial athletic benefits and satisfaction of the training program. Objective testing included the triple hop test and T-Drill hop test to assess the training program on improving horizontal distance hopped, time hopped, limb symmetry, and landing mechanics. The dancers reported high perceived substantial benefits in 79% (22 of 28) for teaching proper take-off and landing mechanics, and in 96% (27 of 28) for the program challenging and preparing them for dance activities. A high dancer satisfaction rating was reported in 93% (26 of 28 dancers) for the training program. A significant increase in distance hopped occurred in right and left lower limbs on the triple hop test ( p < 0.001). A significant decrease in time to complete the T-Drill hop test was reported on right and left lower limbs ( p < 0.001). The psychometric results of the high substantial athletic benefits, major overall satisfaction, and increased hop drill performance warrant the recommendation of this training program for ballet dancers.
A Weight lifting Belt Increases Squat Performance and Subjectively Perceived But Not Objectively Measured Postural Stability.
Veltzke F, Qiu F, Bey ME … +1 more , Legerlotz K
J Strength Cond Res · 2026 Mar · PMID 41860443 · Publisher ↗
Veltzke, F, Qiu, F, Bey, ME, and Legerlotz, K. A weightlifting belt increases squat performance and subjectively perceived but not objectively measured postural stability. J Strength Cond Res XX(X): 000-000, 2026-Weight...
Veltzke, F, Qiu, F, Bey, ME, and Legerlotz, K. A weightlifting belt increases squat performance and subjectively perceived but not objectively measured postural stability. J Strength Cond Res XX(X): 000-000, 2026-Weight lifting belts are subjectively perceived to enhance stability and improve athletic performance. However, the mechanisms underlying performance enhancement are poorly researched. This study thus aims to determine whether athletic performance and postural stability are objectively increased by wearing a weightlifting belt, and whether the effects are affected by sex or experience with belt application. Belt experienced (n = 15) and unexperienced (n = 14) men (height 182 ± 7 cm; body mass 88 ± 10 kg), and experienced (n = 11) and unexperienced (n = 9) women (height 168 ± 6 cm; body mass 66 ± 6 kg) participated in 2 measurement sessions 1 week apart. In each session, 2 sets of squats to exhaustion with the beltless 6 repetition maximum weight were performed while standing on force plates, wearing (B) or not wearing (noB) the belt in a randomized order, which was reversed in the second measurement session. The number of repetitions, movement duration, postural sway, and subjectively perceived stability were compared between conditions. With belt application, the number of repetitions increased, regardless of sex or belt experience (B_8.1 ± 1.7; noB_6.5 ± 1.3, ρ < 0.001; Wilcoxon-Test), whereas the duration of the concentric phase of squats decreased (B_1.99 ± 0.2 s; noB_2.09 ± 0.2 s, ρ < 0.001; t-Test). Wearing the belt subjectively increased postural stability (Score_3.7; ρ < 0.001; t-Test), but did not do so objectively. The path length, adjusted for movement duration, was significantly increased in experienced individuals (noB_13.4 ± 2.3 cm·s-1; B_13.7 ± 2.8 cm·s-1; ρ = 0.045; t-Test). Belt application led to an improvement in squat performance, in terms of increased movement velocity and number of repetitions, in both men and women, irrespective of prior experience. However, this improvement cannot be attributed to an increase in postural stability.
Effects on Heart Rate Variability of a European Under-18 Rugby Tournament.
Solís-Mencía C, Jiménez-Herranz E, Cano-Cappellacci M … +6 more , Ibacache-Saavedra P, García-Fernández P, de Sousa-De Sousa L, Ramos Veliz R, De Matías-Cid P, Ramos-Álvarez JJ
J Strength Cond Res · 2026 May · PMID 41855375 · Publisher ↗
Solís-Mencía, C, Jiménez-Herranz, E, Cano-Cappellacci, M, Ibacache-Saavedra, P, García-Fernández, P, de Sousa-De Sousa, L, Ramos Veliz, R, De Matías-Cid, P, and Ramos-Álvarez, JJ. Effects on heart rate variability of a E...
Solís-Mencía, C, Jiménez-Herranz, E, Cano-Cappellacci, M, Ibacache-Saavedra, P, García-Fernández, P, de Sousa-De Sousa, L, Ramos Veliz, R, De Matías-Cid, P, and Ramos-Álvarez, JJ. Effects on heart rate variability of a European under-18 rugby tournament. J Strength Cond Res 40(5): e485-e490, 2026-Rugby union is characterized by intermittent efforts combining high and lowintensity actions. In European Under-18 Rugby XV Championship, matches are played every 72 hours, which may hinder adequate recovery. Heart rate variability (HRV) is a noninvasive method that assesses the autonomic nervous system activity, yet its role to measure the rugby players recovery remains underexplored. The purpose of this study was to evaluate HRV responses in elite under-18 rugby players during an European Championship with matches every 72 hours. This prospective study was conducted with 27 players from the Spanish under-18 national rugby team. HRV data were collected daily for 12 days, including pretournament preparation and 3 matches. Measurements were taken in a supine resting position using a Bluetooth chest-strap. Time-domain, frequency-domain, and nonlinear HRV metrics were analyzed. Statistical comparisons were made using Friedman and Wilcoxon tests ( p < 0.05). HRV metrics showed no significant differences between pretournament values and the first match day (first MD). However, time-domain, frequency-domain, and nonlinear variables significantly decreased after the first MD compared with the second (second MD) and third match days (third MD) ( p < 0.0001). No significant differences were observed between the second MD and third MD. These findings suggest persistent autonomic imbalance and insufficient recovery between matches. Playing matches every 72 hours does not allow for adequate recovery in under-18 rugby players. Daily HRV monitoring provides a valuable tool for assessing fatigue, guiding training load management, and reducing injury risk during competitive tournaments.
Effect of Ischemic Preconditioning Interventions With Different Cycles on Exercise Performance in Team Sport Athletes.
Öztürk F, Ceylan B, Balcı ŞS
J Strength Cond Res · 2026 Mar · PMID 41855311 · Publisher ↗
Öztürk, F, Ceylan, B, and Balcı, ŞS. Effect of ischemic preconditioning interventions with different cycles on exercise performance in team sport athletes. J Strength Cond Res XX(X): 000-000, 2025-This study examined the...
Öztürk, F, Ceylan, B, and Balcı, ŞS. Effect of ischemic preconditioning interventions with different cycles on exercise performance in team sport athletes. J Strength Cond Res XX(X): 000-000, 2025-This study examined the effects of ischemic preconditioning (IPC) interventions with different cycle durations on anaerobic and agility performance and recovery in team sport athletes. Twelve young female athletes completed 4 visits. During the first visit, anthropometric assessments and familiarization procedures were conducted. In the remaining visits, athletes completed 1 of 3 conditions-IPC 1 × 5 minutes, IPC 3 × 5 minutes, or control-in a randomized order. Each session comprised a Modified Agility Test and the Running-Based Anaerobic Sprint Test, followed by a 5-minute recovery period. A 7-day rest period was given between conditions. Both IPC interventions significantly improved peak power output compared with control condition (p = 0.01). Mean power was higher after IPC 1 × 5 minutes than control (p = 0.01), with no significant differences between the other conditions. Agility performance improved after IPC 3 × 5 minutes compared with after IPC 1 × 5 minutes (p = 0.01) but showed no difference relative to control (p > 0.05). Heart rate (HR) values were lower after IPC interventions than in the control condition (p = 0.01), indicating enhanced cardiovascular recovery. However, IPC had no significant effect on ratings of perceived exertion scores or the time course of HR recovery. In conclusion, IPC enhanced specific aspects of anaerobic performance and supported cardiovascular recovery. Given the comparable outcomes across conditions, the shorter IPC protocol (1 × 5 minutes) may represent a practical alternative to its longer counterpart.
Menstrual Cycle Influence on Post-exercise Recovery: Comparing the Efficacy of Dry and Ice Massage in Female Combat Sports Athletes.
Trybulski R, Smoter M, Vovkanych A … +2 more , Svyshch Y, Clemente FM
J Strength Cond Res · 2026 May · PMID 41848720 · Publisher ↗
Trybulski, R, Smoter, M, Vovkanych, A, Svyshch, Y, and Clemente, FM. Menstrual cycle influence on post-exercise recovery: comparing the efficacy of dry and ice massage in female combat sports athletes. J Strength Cond Re...
Trybulski, R, Smoter, M, Vovkanych, A, Svyshch, Y, and Clemente, FM. Menstrual cycle influence on post-exercise recovery: comparing the efficacy of dry and ice massage in female combat sports athletes. J Strength Cond Res 40(5): 597-609, 2026-This study investigated how menstrual cycle phases affect recovery in female athletes after intense exercise, comparing dry massage and ice massage. Thirty-three combat sports athletes (age: 25.3 ± 2.1) were divided into 3 groups: dry massage, ice massage, and control. Subjects underwent an intense plyometric session during both the early-follicular and mid-luteal phases of their menstrual cycle. Measurements of muscle stiffness (MS), pressure pain threshold (PPT), cutaneous microvascular blood flow (CMBF), reactive strength index (RSI), creatine kinase (CK), and total quality of recovery (TQR) were taken pre- and post-exercise, at 24 and 72 hours. Massage groups received treatment twice daily for 3 days per cycle. Both dry and ice massages significantly reduced CMBF and MS and increased PPT compared with control up to 24 hours posttreatment ( p < 0.001), though effects differed at 72 hours. In addition, recovery in these 3 measures was greater during the early-follicular phase compared with the mid-luteal phase ( p < 0.05), with significant effects observed on CMBF and PPT. Reactive strength index and total quality of recovery were significantly higher at 24 and 72 hours in both massage groups compared with the control ( p < 0.001). Meanwhile, CK levels were significantly superior in both experimental groups only at 72 hours post-session ( p < 0.001) when compared with the control. Menstrual cycle phase did not influence CK, while RSI and TQR showed slight differences. In conclusion, both dry and ice massage effectively enhance recovery following intense exercise, particularly in improving MS, PPT, and CMBF, with the early-follicular phase showing slightly better recovery outcomes than the mid-luteal phase.
Feelings in the Lift: Comparing Perceptual Responses to Cluster and Traditional Resistance Training Protocols.
de Souza Soares B, Mohammad J, Cantelmo CE … +3 more , Gomes Alves MC, de Oliveira Barros BC, Vieira de Oliveira G
J Strength Cond Res · 2026 May · PMID 41848692 · Publisher ↗
de Souza Soares, B, Mohammad, J, Cantelmo, CE, Gomes Alves, MC, de Oliveira Barros, BC, and Vieira de Oliveira, G. Feelings in the lift: Comparing perceptual responses to cluster and traditional resistance training proto...
de Souza Soares, B, Mohammad, J, Cantelmo, CE, Gomes Alves, MC, de Oliveira Barros, BC, and Vieira de Oliveira, G. Feelings in the lift: Comparing perceptual responses to cluster and traditional resistance training protocols. J Strength Cond Res 40(5): e437-e444, 2026-This study compared the acute effects of traditional vs. cluster resistance training (RT) protocols on affective valence, arousal, enjoyment, and rating of perceived exertion (RPE) in resistance-trained young adults. Sixteen subjects completed 2 lower-limb RT sessions in a randomized crossover design: 1 with a traditional configuration and another with cluster sets. Affective valence declined during and after the traditional session ( p < 0.05), but remained stable across time in the cluster session, with a significant protocol × time interaction ( p < 0.001). Perceived activation increased in both conditions ( p < 0.001) but was significantly higher after the traditional protocol ( p = 0.04; d = 0.7, 95% confidence interval (CI) [0.12-1.21]). Enjoyment was significantly greater ( p < 0.01; d = 0.7, 95% CI [-1.31 to -0.18]), and RPE significantly lower ( p < 0.001; d = 1.2, 95% CI [0.52-1.82]) following the cluster session. Rating of perceived exertion negatively correlated with enjoyment ( r = -0.54, p = 0.03) and affective valence ( r = -0.54, p = 0.032) in the traditional condition. These results suggest that RT set configuration acutely modulates psychoaffective outcomes. Cluster RT elicits more favorable affective and perceptual responses, which may enhance exercise enjoyment and support long-term adherence.
The Free Leg Position During Unilateral Squat Jumps Influences the Bilateral Deficit.
Schmidt C, Lligona J, Müller M … +3 more , Langenauer J, Herr M, Malatesta D
J Strength Cond Res · 2026 Mar · PMID 41838408 · Publisher ↗
Schmidt, C, Lligona, J, Müller, M, Langenauer, J, Heer, M, and Malatesta, D. The free leg position during unilateral squat jumps influences the bilateral deficit. J Strength Cond Res XX(X): 000-000, 2026-The aim of this...
Schmidt, C, Lligona, J, Müller, M, Langenauer, J, Heer, M, and Malatesta, D. The free leg position during unilateral squat jumps influences the bilateral deficit. J Strength Cond Res XX(X): 000-000, 2026-The aim of this investigation was twofold: (a) to compare bilateral deficit (BLD), assessed using vertical jump performance with 2 different unilateral jump techniques in squat jump (SJ): flexed (Classic technique) and straight (FC Luzern technique) free leg; and (b) to examine whether age affected BLD assessed in players' age categories of the same professional club. Eighty-one soccer players of a Super League professional club participated in this study and were separated by age categories: Senior (older than 21 years), under-21 (U21), under-18 (U18), under-16 (U16), and under-15 (U15) categories/teams. The mean (Pmean) and peak (Ppeak) vertical mechanical powers were measured during the push-off phase of bilateral and unilateral (Classic and FC Luzerne [FCL] techniques) SJs using twin force plates. Compared with FCL technique, BLD was significantly higher for the Classic technique (p < 0.001) and presented higher values when the Ppeak (BLDPpeak; +8.7%), Pmean (BLDPmean; +10.2%), and Fmean (BLDFmean; +3.1%) were used to evaluate BLD. There were no significant differences in BLDPpeak (p = 0.898), BLDPmean (p = 0.427), and BLDFmean (p = 0.089) across age categories for either of the unilateral jump techniques used to calculate BLD. We demonstrated that BLD is influenced by the unilateral SJ technique used. Using FCL unilateral SJ with a straight free leg ensures similar biomechanical conditions in both unilateral and bilateral SJs, allowing for a more accurate assessment of BLD. In addition, although there were some significant differences in biomechanical SJ variables across age categories, our findings showed that age did not influence BLD for either jump technique.
Informing Fitness Testing Data Reporting and Visualization in Elite Soccer: A Survey Into Practitioner Preferences and Needs.
Asimakidis ND, Beato M, Parmar N … +3 more , Weldon A, Bishop C, Turner AN
J Strength Cond Res · 2026 May · PMID 41837742 · Publisher ↗
Asimakidis, ND, Beato, M, Parmar, N, Weldon, A, Bishop, C, and Turner, AN. Informing fitness testing data reporting and visualization in elite soccer: A survey into practitioner preferences and needs. J Strength Cond Res...
Asimakidis, ND, Beato, M, Parmar, N, Weldon, A, Bishop, C, and Turner, AN. Informing fitness testing data reporting and visualization in elite soccer: A survey into practitioner preferences and needs. J Strength Cond Res 40(5): e520-e529, 2026-This cross-sectional survey explored elite soccer practitioners' fitness testing reporting and visualization preferences. Overall, 145 soccer practitioners completed an online survey comprising 27 questions, with 3 sections: (a) background information, (b) preferences for fitness testing report content and insights, and (c) preferences and interpretation of data visualization formats. Fixed-response questions were analyzed using frequency analysis, while thematic analysis was applied to open-ended questions to generate key themes. Subjects predominantly valued tracking changes (91%) in performance over benchmark (61%) or position-specific (58%) comparisons. Although 44.8% prioritized individual performance, 42.1% emphasized both individual and team-level insights. Concerning the presentation of data, raw scores were the preferred format (62.1%), followed by standardized (37.2%) and composite scores (23.5%), depending on the context. Subjects highly valued interactive dashboards (91%), quadrant charts (87.6%), and traffic light systems (77.2%). Bar charts (77.2%) were the preferred visual format for interplayer comparisons, valued for their clarity, and reduced cognitive load, while line charts (51.7%) were favored for tracking performance over time, due to their simplicity and user familiarity. Radar charts (59.3%) were the preferred format for comparing individual performances to the wider team, valued for their ability to provide a holistic overview of strengths and weaknesses. Uncertainty indicators were endorsed by 52.3%, primarily for enhancing data interpretation and decision making, although concerns were raised about their ease of understanding and visual clutter. Practitioners can use this study's findings to inform user-friendly reporting strategies and meet diverse audience needs. Findings should also support practitioner training and the adoption of evolving industry practices.
Technical Note on Pickup Acceleration Signal Processing.
Pryer ME, Cronin J, Neville J … +2 more , Korfist C, Uthoff A
J Strength Cond Res · 2026 Apr · PMID 41811348 · Publisher ↗
Pryer, ME, Cronin, J, Neville, J, Korfist, C, and Uthoff, A. Technical note on pickup acceleration signal processing. J Strength Cond Res 40(4): e432-e436, 2026-Sprint acceleration from dynamic positions (pickup accelera...
Pryer, ME, Cronin, J, Neville, J, Korfist, C, and Uthoff, A. Technical note on pickup acceleration signal processing. J Strength Cond Res 40(4): e432-e436, 2026-Sprint acceleration from dynamic positions (pickup acceleration) is fundamental to team sports performance, yet remains under-researched. This article focuses on customizing methods for extracting step-specific variables from motorized linear position encoder technology to analyze pickup acceleration. Fifteen trained athletes (22.6 ± 5.3 years) from diverse sporting backgrounds performed 30-m sprints at controlled entry velocities (1.5 and 3.0 m·s -1 ). A custom MATLAB script identified critical steps and calculated step velocity, acceleration, horizontal force, and step length. The analysis captured approach steps (-2, -1), transition step (0), and pickup steps (1, 2) across the acceleration phase. Using the methods outlined in this article, it was concluded that a step-by-step analysis of pickup acceleration can be effectively captured in field settings, providing mechanical insights that were previously limited to laboratory environments. This method provides strength and conditioning practitioners with a practical and portable solution for assessing sport-specific sprint mechanics. While low-load resistance (1 kg) and tether oscillation present limitations, the approach enables individualized training prescriptions based on step-specific mechanical profiles. Future research should establish the reliability of step-derived measures and explore targeted interventions for improving pickup acceleration performance in team sport athletes.
The Impact of Load per Kilogram of Body Mass Carried on Dynamic Postural Stability in Firefighter Cadets.
Kollock RO, Hale WD, Fulk M … +4 more , Sullivan C, Thomas J, Sanders G, Peveler W
J Strength Cond Res · 2025 Sep · PMID 41811124 · Publisher ↗
Kollock, RO, Hale, WD, Fulk, M, Sullivan, C, Thomas, J, Sanders, G, and Peveler, W. The impact of load per kilogram of body mass carried on dynamic postural stability in firefighter cadets. J Strength Cond Res 39(9): e11...
Kollock, RO, Hale, WD, Fulk, M, Sullivan, C, Thomas, J, Sanders, G, and Peveler, W. The impact of load per kilogram of body mass carried on dynamic postural stability in firefighter cadets. J Strength Cond Res 39(9): e1105-e1111, 2025-Slips, trips, and falls continue to be one of the leading causes of injury on the fireground. The load per kilogram (kg) of body mass carried (LpBM) in equipment and gear (EQG) by firefighters may contribute to fall susceptibility. The primary purpose of this study was to determine whether LpBM was a significant predictor of dynamic postural stability (DPSI) while controlling for anthropometrics such as height, body mass, and body mass index (BMI). Ninety-nine male fire cadets participated in the study. Subjects performed 3 trials of the single-leg landing and stabilization task without and with EQG. The main outcome measures were DPSI with EQG and the percentage difference in DPSI. Two separate polynomial regressions were conducted to determine whether LpBM was a significant predictor of DPSI with EQG and the percentage difference in DPSI. Body mass, height, and BMI were used as covariates in each analysis. LpBM was a significant predictor of DPSI with EQG (p < 0.001) and the percentage difference in DPSI (p < 0.001) with and without EQG. Body mass, height, or BMI do not significantly (p's > 0.05) contribute to DPSI with EQG or percentage difference in DPSI. The results suggest that firefighters with a body mass between 93 and 95 kg can expect an approximate increase of 39% in DPSI with EQG.
Manuscript Clarification.
Eserhaut DA, DeLeo JM, Fry AC
J Strength Cond Res · 2025 Sep · PMID 41811123 · Publisher ↗
Abstract loading — click title to view on PubMed.
Manuscript Clarification for Eserhaut DA, DeLeo JM, Fry AC. Blood Flow Restricted Resistance Exercise in Well-Trained Men: Salivary Biomarker Responses and Oxygen Saturation Kinetics. J Strength Cond Res 38: e716-e726, 2024.
Gentles JA
J Strength Cond Res · 2025 Sep · PMID 41811122 · Publisher ↗
Abstract loading — click title to view on PubMed.
Physical Characteristics That Differentiate Playing Levels of Male Rugby Union Players: A Systematic Review.
Payne LKD, Varley MC, Driller MW … +1 more , James LP
J Strength Cond Res · 2025 Sep · PMID 41811121 · Publisher ↗
Payne, LKD, Varley, MC, Driller, MW, and James, LP. Physical characteristics that differentiate playing levels of male rugby union players: a systematic review. J Strength Cond Res 39(9): 1013-1022, 2025-The distinct str...
Payne, LKD, Varley, MC, Driller, MW, and James, LP. Physical characteristics that differentiate playing levels of male rugby union players: a systematic review. J Strength Cond Res 39(9): 1013-1022, 2025-The distinct strength and speed characteristics differentiating Rugby Union athletes by playing level remain unclear, as do their associations with game performance indicators. This review systematically evaluated physical characteristics of adult male Rugby Union athletes across professional, semi-professional, and amateur levels. Five databases (PubMed, CINAHL, SPORTDiscus, Web of Science, Scopus) were searched, yielding 54 eligible studies. Higher-level athletes consistently demonstrated superior heavy dynamic strength (5/5 studies) and fast dynamic strength (3/3 studies). Results were mixed for acceleration (4/5 studies) and maximal sprint speed (3/6 studies), whereas limited evidence supported greater maximal isometric strength (1/1 study) and reactive strength (1/1 study). Explosive strength remains unexplored. Significant associations were observed between strength and speed characteristics and game performance indicators, except for explosive strength because of a lack of investigation. Heavy and fast dynamic strength emerged as key differentiators of playing levels and correlated strongly with game performance metrics. In contrast, findings for sprint speed and acceleration were inconsistent. This review highlights critical gaps in research, particularly regarding maximal isometric, explosive, and reactive strength, providing insights for future studies and practical applications in Rugby Union training.
The Impact of Verbal Instruction on Countermovement Jump Testing in Division I Volleyball Athletes.
Young TL, Haynes HK, Klubertanz MR … +5 more , Patton MG, Mercer ZJ, Bruni KM, Graybeal AJ, Donahue PT
J Strength Cond Res · 2026 Jun · PMID 41785423 · Publisher ↗
Young, TL, Haynes, HK, Klubertanz, MR, Patton, MG, Mercer, ZJ, Bruni, KM, Graybeal, AJ, and Donahue, PT. The impact of verbal instruction on countermovement jump testing in Division I volleyball athletes. J Strength Cond...
Young, TL, Haynes, HK, Klubertanz, MR, Patton, MG, Mercer, ZJ, Bruni, KM, Graybeal, AJ, and Donahue, PT. The impact of verbal instruction on countermovement jump testing in Division I volleyball athletes. J Strength Cond Res 40(6): e598-e603, 2026-The countermovement jump (CMJ) is often used to monitor athletes' performance through the interpretation of metrics derived through force plate data collection, and recent advances in technology now allow technicians of all experience levels to easily collect data. This may introduce procedural variation, such as verbal instruction. In addition, athletes competing in sports that place importance on vertical jumping may possess ingrained movement patterns. The purpose of this study was to evaluate if verbal instruction may disrupt an athlete's natural jump strategy, thus clouding interpretation of CMJ profiles. This study uses repeated-measures design with significance set at 0.05 to evaluate differences in jump variables under 3 different instructional conditions. Twelve female DI volleyball athletes performed 9 total jumps on a force platform, 3 under each condition. The instructions include: "jump as high as possible" (CMJ-H), "jump as fast as possible" (CMJ-F), and "jump to the best of your ability" (CMJ-N). No differences in jump height, braking impulse, and propulsive impulse were observed across conditions ( p > 0.05). However, force variables and reactive strength index modified were significantly higher, and temporal variables were significantly lower under CMJ-F compared with CMJ-H and CMJ-N ( p < 0.05). In addition, countermovement depth was significantly shallower under CMJ-F. Conversely, no significant differences were observed for any variables between CMJ-H and CMJ-N ( p > 0.05). The CMJ-F condition elicits an increase in force production, whereas CMJ-H and CMJ-N elicit an elongation of time. This study indicates the need for procedural consistency regarding the instruction used.
Kinetic and Kinematic Effects of Flag-Carrying on Change of Direction and Sprinting Performance in Assistant Referees.
Grazer J, Reed WJ, Mangine G … +3 more , Hester G, Huet K, Edwards W
J Strength Cond Res · 2026 Mar · PMID 41740128 · Publisher ↗
Grazer, J, Reed, WJ, Mangine, G, Hester, G, Huet, K, and Edwards, W. Kinetic and kinematic effects of flag-carrying on change of direction and sprinting performance in assistant referees. J Strength Cond Res 40(3): e292-...
Grazer, J, Reed, WJ, Mangine, G, Hester, G, Huet, K, and Edwards, W. Kinetic and kinematic effects of flag-carrying on change of direction and sprinting performance in assistant referees. J Strength Cond Res 40(3): e292-e297, 2026-Within competitive soccer, assistant soccer referees (AR) are expected to keep up with the top speed of players on the field, despite potentially being hindered by holding a flag down by their side. Their ability to keep up with speed-of-play can determine effectiveness of decisions on the field, yet standardized AR fitness assessments do not consider these challenges. The purpose of this study was to examine kinetic and kinematic effects of flag-carrying within sprinting and change-of-direction performance in ARs. Eighteen male referees (age: 31 ± 9 years, height: 1.78 ± 0.60 m, mass: 81.9 ± 10.6 kg) performed 6 trials each of 60-m sprints and a standardized change-of-direction ability test (CODA). Each referee ran 3 trials with and without a flag in a randomized order. Two-way repeated measures analysis of variance (analyses of variance) was used to determine differences between trials and condition. Total sprint time (2.52%, p < 0.01) and total step count (1.86%, p < 0.01) decreased during the non-flag-carrying condition. Kinetic and kinematic variables including force, velocity, and power within the top speed phase also saw increases (p ≤ 0.01), but none were observed within the acceleration phase or CODA test (p > 0.05). Flag-carrying seems to negatively affect top speed but not acceleration or change of direction performance. Practitioners should use methods that can enhance top-end sprinting performance for ARs due to the potential hindrance of top-end sprinting performance while carrying a flag. Future studies may benefit by assessing body position to determine specific aspects of sprinting that are negatively affected by flag carrying.
Effects of Optical Illusion With a Sensorimotor Training on Somatosensory and Motor Function in Healthy Subjects: A Randomized Controlled Trial.
Grande-Alonso M, Cuenca-Martínez F, Pérez-González A … +6 more , Cividanes-García N, Martín-Tejedor C, Soriano M, Vidal-Quevedo C, Forner-Álvarez C, La Touche R
J Strength Cond Res · 2026 Mar · PMID 41740127 · Publisher ↗
Grande-Alonso, M, Cuenca-Martínez, F, Pérez-González, A, Cividanes-García, N, Martín-Tejedor, C, Soriano, M, Vidal-Quevedo, C, Forner-Álvarez, C, and La Touche, R. Effects of optical illusion with a sensorimotor training...
Grande-Alonso, M, Cuenca-Martínez, F, Pérez-González, A, Cividanes-García, N, Martín-Tejedor, C, Soriano, M, Vidal-Quevedo, C, Forner-Álvarez, C, and La Touche, R. Effects of optical illusion with a sensorimotor training on somatosensory and motor function in healthy subjects: a randomized controlled trial. J Strength Cond Res 40(3): e233-e240, 2026-The main objective was to assess the effects of an intervention with optical illusion glasses along with sensorimotor training based on cross-learning on somatosensory and motor variables in healthy subjects. This study was a randomized single-blind controlled trial. A total of 38 healthy subjects were randomly distributed into 2 groups: optical illusion group (OIG) and nonoptical illusion group (N-OIG). All subjects underwent 8 intervention sessions based on sensorimotor training on the dominant side. The OIG conducted the training using Prism Glasses branded graphs which acted as a mirror therapy. A pre, middle, and postassessment of tactile sensitivity, manual dexterity, and pain sensitivity was conducted. The OIG showed greater changes in tactile sensitivity of the dominant epicondyle than sensorimotor training alone. In manual dexterity, both groups produced significant improvements at the end of the intervention. Finally, only the OIG resulted in significant local hypoalgesia at the end of the intervention. It seems that using optical illusion glasses, together with a sensorimotor training program, has a greater impact than a sensorimotor training program alone on tactile sensitivity, very complex manual dexterity tasks, and on the improvement of pain sensitivity at least locally. The findings of this article suggest that integrating OI glasses into training regimens may enhance outcomes for athletes or individuals undergoing rehabilitation. Further studies should be conducted with the aim of having a transfer to a clinical population with pain or sensorimotor impairment.
Effects of High-Intensity Interval Training Versus Sprint Interval Training on Factors Related to Endurance Performance: A Systematic Review and Meta-Analysis.
Xiao Y, Li J, Deng Z … +1 more , Gao W
J Strength Cond Res · 2026 Mar · PMID 41740126 · Publisher ↗
Xiao, Y, Li, J, Deng, Z, and Gao, W. Effects of high-intensity interval training versus sprint interval training on factors related to endurance performance: A systematic review and meta-analysis. J Strength Cond Res 40(...
Xiao, Y, Li, J, Deng, Z, and Gao, W. Effects of high-intensity interval training versus sprint interval training on factors related to endurance performance: A systematic review and meta-analysis. J Strength Cond Res 40(3): 344-355, 2026-This meta-analysis aimed to compare the long-term effects (≥2 weeks) of high-intensity interval training (HIIT) and sprint interval training (SIT) on endurance performance-related outcomes, including maximal oxygen uptake (V̇o2max), endurance performance, maximal aerobic power/velocity (MAP/MAV), lactate threshold, and running economy. A systematic literature search was conducted using the keywords "high-intensity interval training" and "sprint interval training" in the Web of Science, PubMed, and SPORTDiscus databases. A random-effects model was applied, with standardized mean difference (SMD) calculated for each outcome. Subgroup and regression analyses were performed to examine potential moderating factors. Twelve randomized crossover trials involving 460 subjects were included. High-intensity interval training significantly outperformed SIT in improving V̇o2max (SMD = 0.56, 95% confidence interval [CI]: 0.23-0.88; p < 0.001) and MAP/MAV (SMD = 0.40, 95% CI: 0.06-0.75; p = 0.02). Subgroup analysis revealed that HIIT programs lasting more than 8 weeks were particularly effective for enhancing V̇o2max (SMD = 2.13, p = 0.01), while protocols incorporating work intervals longer than 4 minutes also showed significant benefits (SMD = 1.40, p = 0.03). Furthermore, HIIT resulted in greater improvements in time trial performance compared with SIT in moderately trained individuals. HIIT showed greater improvements in aerobic capacity than SIT, particularly for long-interval protocols (>4 minutes, >8 weeks). Although most outcomes were of low or very low quality (except MAP/MAV), these findings suggest that athletes and coaches may incorporate 3-6 intervals of 4-5 minutes at 80-95% MAV, 2-3 sessions per week, to enhance aerobic capacity.
Assessing Agreement in Lower-Body Joint Interlimb Asymmetries in Isometric, Dynamic, and Loaded Conditions.
Rosenblum LJ, Lovalekar M, Martin BJ … +8 more , Feigel ED, Mroz KH, McCarthy AM, Koltun KJ, Stefl TJ, Forse JN, Doyle TLA, Nindl BC
J Strength Cond Res · 2026 Mar · PMID 41740125 · Publisher ↗
Rosenblum, LJ, Lovalekar, M, Martin, BJ, Feigel, ED, Mroz, KH, McCarthy, AM, Koltun, KJ, Stefl, TJ, Forse, JN, Doyle, TLA, and Nindl, BC. Assessing agreement in lower body joint inter-limb asymmetries in isometric, dynam...
Rosenblum, LJ, Lovalekar, M, Martin, BJ, Feigel, ED, Mroz, KH, McCarthy, AM, Koltun, KJ, Stefl, TJ, Forse, JN, Doyle, TLA, and Nindl, BC. Assessing agreement in lower body joint inter-limb asymmetries in isometric, dynamic, and loaded conditions. J Strength Cond Res 40(3): 283-292, 2026-Interlimb asymmetry (ILA) for static and dynamic movements can indicate aberrant musculoskeletal and neuromuscular function. The purpose of this analysis was to measure ILA agreement in different isometric, dynamic, and loaded conditions at the ankle, knee, and hip, for single-joint and lower-body ILA; to assess the effect of a load on kinetic and kinematic ILA during jumps; and to evaluate the effect of physiological fatigue on gait ILA. Twenty-two men (30.2 ± 5.0 years, 1.8 ± 0.08 m, 85.6 ± 10.0 kg, 16.9 ± 5.4% body fat) participated in ankle, knee, hip, and lower-body assessments of relative (N·kg-1) and peak isometric strength (N); dynamic peak range of motion (º) and dynamic peak forces (N) without and with load (9.7 kg); and tibial impact (g) during aerobic capacity tests (pre- and at-fatigue). Agreements between ILA (≥10% vs. <10%) were calculated using different variables and assessed across different formulae through Kappa coefficients (κ). The difference in ILA with and without load, and pre- and at-fatigue, was analyzed using paired t-tests (α = 0.05). An analysis of single-joint ILA showed good agreement between the formulae (κ range: 0.412-1.00, p values: 0.045-<0.001), but poor agreement with lower-body ILA. Load increased ILA in both countermovement and drop jumps, whereas physiological fatigue did not. This research estimated normative baseline ILAs for military personnel and showed that ILA is a task-, metric-, and joint-specific measurement.
Accentuate the Negative? Effects of Eccentric Overload on Muscular Adaptations During Split Jerk Performance.
Roderick K, Comfort P, Suchomel TJ … +2 more , Swinton PA, Schoenfeld BJ
J Strength Cond Res · 2026 Mar · PMID 41740124 · Publisher ↗
Roderick, K, Comfort, P, Suchomel, TJ, Swinton, PA, and Schoenfeld, BJ. Accentuate the negative? Effects of eccentric overload on muscular adaptations during split jerk performance. J Strength Cond Res 40(3): 255-264, 20...
Roderick, K, Comfort, P, Suchomel, TJ, Swinton, PA, and Schoenfeld, BJ. Accentuate the negative? Effects of eccentric overload on muscular adaptations during split jerk performance. J Strength Cond Res 40(3): 255-264, 2026-We aimed to assess the effectiveness of using accentuated eccentric loading (AEL) with the split jerk to enhance muscular adaptations of experienced weightlifters during an 8-week training cycle. Eighteen subjects with at least 1 year of consistent split jerk training were randomly assigned to an experimental group that used AEL training for the split jerk or a traditional loading group. Both training programs included weightlifting competition lifts and their derivatives, strength movements such as the back squat, and accessory exercises that targeted midline stability. Both groups trained the split jerk twice a week for 5 working sets per session and 3 repetitions per set, with AEL using weight releasers to unload at completion of the dip phase. Body composition, anthropometric, and 1 repetition maximum split jerk and back squat outcomes were assessed. Bayesian analyses including hierarchical models that produced summary standardized mean difference comparisons for each outcome category were performed. Results were uncertain, with estimates either close to zero (Pooled Strength z = 0.01 [95% CI: -0.30 to 0.26]) or tending to favor AEL (Pooled Body Composition z = 0.10 [95% CI: -0.12 to 0.27]; Pooled Anthropometry z = 0.07 [95%CI: -0.06 to 0.20]). In conclusion, we obtained insufficient data to clearly support hypotheses of superior muscular adaptations when applying AEL during split jerk training for an 8-week intervention compared with traditional methods in weightlifters. However, central estimates tended to indicate small effects favoring AEL, warranting further investigation with different training program designs, larger sample sizes, and longer intervention durations.
About
- Frequency
- Sun
- Papers found
- 200
- RSS feed
- Subscribe