International Journal of Strength and Conditioning
International Journal of Strength and Conditioning (IJSC) The International Journal of Strength and Conditioning (IJSC), presented by the International Universities Strength and Conditioning Association (IUSCA), is a leading peer-reviewed academic journal dedicated to advancing research in sports science, sports performance, and strength & conditioning. As a Diamond Open Access journal, the IJSC ensures that all published research is freely accessible to the global community, fostering collaboration and innovation. Our mission is to provide high-quality, impactful research that bridges the gap between academia and practice. This mission is made possible through the generous support of organizations, institutions, and individuals who share our commitment to advancing the fields of sports performance and exercise science. Key partnerships with organizations such as JISC and LYRASIS enable us to maintain our open access model and ensure the sustainability of the journal. As a non-profit organization, the IUSCA relies on community and partner support to continue delivering free, world-class research to the strength and conditioning community. If you find value in the IJSC, please consider: Joining the JISC or LYRASIS schemes, or Making a tax-deductible donation to support our mission and the open access movement. ISSN: 2634-2235 International Universities Strength and Conditioning Association (IUSCA)
International Universities Strength and Conditioning Association (IUSCA)
Authors retain copyright of their work, granting IJSC a license to publish and distribute. All articles are distributed under the Creative Commons Attribution 4.0 License. We clearly state any fees associated with submissions or access for readers. For copyright or licensing queries, stakeholders can reach out to journal@iusca.org.
The Sound of Strength: Auditory Feedback Enhances Squat Performance in Resistance-Trained Females
Introduction: Kinematic feedback during resistance training (RT) can improve performance, but most research has focused on males. Since conscientiousness levels related to feedback may differ between genders, this study examined how auditory and visual kinematic feedback affects squat performance in resistance-trained females. Methods: Seventeen resistance-trained females (21.2 ± 2.4 years; 3.8 ± 2.3 years training experience) performed three sets of 10 repetitions barbell back squats at 75% of 3RM under three randomized conditions: no feedback (CON), auditory feedback (AUD), and visual feedback (VIS). Average (AV) and peak (PV) concentric barbell velocity were measured using a PUSH band, and enjoyment was assessed using the Exercise Enjoyment Scale. Results: Feedback x rep interaction were found for both AV (p = .004, ηp² = .02) and PV (p < .001, ηp² = .03). Simple-slope comparisons showed AUD produced a less negative decline than CON for both AV (p = .002, d = 0.82) and PV (p < .001, d = 0.94). Main effect for percentage velocity loss (from rep 1–10) were found in feedback for AV (p = .015, ηp² = .23) and PV (p = .021, ηp² = .21). AUD had significantly less reduction in AV (9.5%) and PV (6.9%) vs CON (AV 23.1%, PV 19.0%). No significant differences were found between the other conditions in either slope or velocity loss comparisons (p = .068-449). Furthermore, both VIS (p < 0.05, r = 0.65) and AUD (p < 0.05, r = 0.69) feedback were rated more enjoyable than CON, with no difference between AUD and VIS (p = 0.57, r = 0.14). When asked about preferences, 70% of the participants favored AUD. Conclusion: Feedback helps preserve barbell velocity, reducing velocity loss across repetitions in resistance-trained females. Auditory feedback emerged as particularly effective for maintaining barbell velocity compared to no feedback and was the preferred feedback condition.
Copyright (c) 2026 Tom Erik Solstad, Matthew Shaw, Atle Hole Saeterbakken, Martin Ziegler, Inger Anne Urkdal, Anna Marita Oma, Vidar Andersen https://creativecommons.org/licenses/by/4.0
The Influence of Pre-Training Muscle Size on Strength Gain: An Exploratory Analysis
Purpose: To investigate whether changes in maximal strength following resistance training were influenced by pre-training muscle thickness. Methods: We retrospectively analyzed data from a between-subject study that measured elbow flexor muscle thickness and maximum strength before and after a 6-week study. A total of 122 untrained individuals, who were randomly assigned to 1 of 3 groups, were included in the analyses: (a) time-matched, non-exercise control; (b) dominant arm training; or (c) nondominant arm training. The two training groups performed thrice weekly unilateral elbow flexion exercise, starting with up to 5 heavy singles, followed by 4 sets of 8–12 repetitions to task failure. Results: Increases in strength were observed for both dominant arm [b = 2.29 kg, 95% CI = (1.72, 2.87)] and the non-dominant [b = 2.86 kg, 95% CI = (2.33, 3.39) training groups compared to the time-matched non-exercise control group. However, this increase in strength did not depend upon baseline muscle size for either group. Follow-up mediation analyses suggested that muscle growth mediated changes in strength for the dominant arm but not the nondominant arm training group. Conclusion: We hypothesized that individuals with larger muscles at baseline would have a greater propensity to increase strength compared to those with smaller muscles. However, the magnitude of strength change was not influenced by pre-training muscle thickness. Follow-up mediation analysis on muscle growth was equivocal.
Copyright (c) 2026 William Hammert, Jun Seob Song, Yujiro Yamada, Ryo Kataoka, Anna Kang, Robert Sallberg, Emily Metcalf, Jeremy Loenneke https://creativecommons.org/licenses/by/4.0
Predicting Maximal Aerobic Speed Through Set Distance Time-Trials in Camogie Players: A Pilot Study
Set distance time-trials (TTs) have gained popularity in research and practice as a reliable method for predicting maximal aerobic speed (MAS) in field sport athletes. Therefore, the aim of this pilot study was to investigate applicable TT distances for the establishment of MAS in camogie players. Senior club camogie players (n = 23) undertook the Yo-Yo intermittent recovery test (Yo-Yo IR1) to establish MAS, followed by participation in non-linear, continuous set distance TTs. In a randomised order, players from six balanced groups completed three different TT distances. The TT distances were 1.2 km, 1.4 km, 1.6 km, 1.8 km, 2.0 km, and 2.2 km. Bias, limits of agreement (LOA), linear regression, and bivariate correlation analysis determined the agreement between MAS and average running speed across the TT distances. Average running speed for each TT distance was significantly lower than Yo-Yo IR1-derived MAS (bias ≥ -3.47 ± 0.43 km·h-1, P < 0.05). The 1.2 km TT distance exhibited the least bias and narrowest LOA (-3.47 ± 0.43 km·h-1 [-22.16%] and ±1.68 km·h-1 [±10.73%], respectively). A strong (r = 0.80 [0.44 – 0.94], P = 0.001) to very strong (r = 0.98 [0.91 – 1.00], P < 0.001) positive correlation was found between MAS and average TT running speeds across all TT distances. MAS appeared to be best approximated by the 1.2 km TT in senior club camogie players.
Yo-Yo Intermittent Recovery Test – Level 1
Exercise Science/Exercise Physiology - Strength and Conditioning/Human Performance
Copyright (c) 2026 Seamus Ellis, Colin J. Coyle, Paul J. Byrne https://creativecommons.org/licenses/by/4.0
Isolated Unweighted Fast Knee-Flexions Relate to Maximal Step Frequency and Sprint Speed in Female Track Athletes
We recently introduced an on-field test to quantify knee flexor fatigue in male soccer players using Peak Angular Acceleration of the shank (PAA) during isolated unweighted fast knee flexions. Unexpectedly, we found a positive relation between PAA and 45 m sprint performance in the unfatigued players. This study investigates (1) whether PAA is also positively related to sprint performance in a completely different population—16 female athletes— (2) whether it differs between the first and the second 30 m of a 60 m sprint, and (3) its relationship with step frequency and step length in both phases. Participants wore IMUs on both feet and the shank of the dominant leg. Time gates were placed at 30 and 60 m. Participants performed a series of six fast knee flexions (5s in between) with the dominant leg in a prone position on the floor. The three attempts with the highest PAA were used for analysis. Subsequently, they executed a maximal 60m sprint. The within-session reliability for PAA of the three fastest attempts was high, with a CV of 1.8% and ICC of 0.97. PAA had very strong significant (p<0.05) relations with step frequency (r≥0.72, p≤0.001), moderate (0-30m: r=-0.49, p=0.05) to small (30-60m: r=-0.22 p=0.42) negative relations with step length, and moderate (0-30m: r=0.49, p=0.06) to strong positive relations with speed (30-60m: r=0.57, p=0.02) In conclusion, PAA was moderately related to sprint speed during acceleration and at maximal speed. This was probably due to the very strong relations between PAA and step frequency.
fast muscle contractions, hamstring muscles, inertial measurement unit, field test,
Copyright (c) 2026 Cornelis J de Ruiter, Mark Heiden, Zoë Frederique Sedney, Erik Wilmes https://creativecommons.org/licenses/by/4.0
Drop setting is a mode of resistance exercise that has been historically defined as an immediate reduction in exercise load after set failure to allow more repetitions to be completed. The purpose of the current paper is to posit a modified conceptualization of drop sets and thus propose definitions for drop sets and two related concepts: “drop weight” sets and “drop length” sets. This modified conceptualization stems from the fact that both the external load and resistance arm of an exercise create the resistive torque that ultimately causes set failure (i.e., resistive torque = external load x resistance arm). Consequently, I propose that drop sets be defined as: “a reduction in the resistive torque of an exercise, which typically occurs immediately after a set is taken to failure or high level of fatigue, that allows more repetitions to be completed.” Thus, drop sets can be implemented by reducing either the external load or by shortening the resistance arm between sets. I call the former practice drop weight sets and the latter practice drop length sets. This new definition of drop sets broadens the scope of what a drop set has historically been thought to be, while definitions for drop weight sets and drop length sets are subdivisions of the drop set concept. This re-conceptualization of what a drop set is might enhance communication about resistance exercise and diversify the ways that drop sets are prescribed to increase muscle size and strength.
Copyright (c) 2026 James Nuzzo https://creativecommons.org/licenses/by/4.0
A Preliminary Investigation of the Relationship of Three Key Bar Positions on Weightlifting Performance
Background: There are three fundamental bar positions in weightlifting: 1) Set-up (S), 2) Knee (K), and 3) Power Position (P). Commonly, these positions are evaluated using a clean-grip isometric pull. Purpose: To compare and describe relationships between the three bar positions in an isometric pull and with meet performance in regional to international level weightlifters. Methods: Male (n=6) and female (n=6) weightlifters (age 19-23 yrs.) volunteered. Males were better weightlifters than the females. Pulls were performed from top-down (P - K - S). Isometric peak force (IPF) and rate of force development 0-250ms (RFD250) were derived from force-time curve analysis. A 2x3 mixed ANOVA was used to assess the effects of sex and position. Pearson correlations established relationships. Results: Males produced greater values (both absolute and relative) than females at all positions (p ≤ 0.05). IPF, IPFa and RFD250 at P were greater (p ≤ 0.05) than the other two positions. IPF and IPFa from S and K were similar. Correlations with performance were moderate to strong for absolute and scaled conditions; correlations were generally weaker for females. Correlations for IPF were stronger at S than P. RFD250 correlations were generally stronger at P. Conclusion: Metrics from S and P correlate better with performance than K, with IPF and IPFa favoring S while RFD250 favors P. Both positions seem to be viable options for monitoring weightlifters. Results indicate males and females may produce different relationships, perhaps indicating weakness at specific positions.
Copyright (c) 2026 Wesley Gawel, Marten Bauer, Chieh-Hsin You, Kyle Rochua, Daniel Gahreman, Guy Hornsby, Satoshi Mizuguchi, Michael Stone https://creativecommons.org/licenses/by/4.0
G-Force Tolerance in Fighter Pilots: A Scoping Review With Evidence Gap Map
Background: Despite growing interest in G-force tolerance, the literature remains fragmented, lacking an integrated synthesis that encompasses physiological, cognitive, training, and equipment-related dimensions. Fighter pilots are frequently exposed to high +Gz environments, which can compromise vision, cardiovascular stability, and consciousness. Understanding G-tolerance is vital for flight safety, operational readiness, and the long-term health of aircrew. Objective: This scoping review aims to map the existing evidence on G-force tolerance in fighter pilots and identify key physiological, anthropometric, cognitive, and operational factors. It also seeks to explore enhancement strategies and assess underrepresented populations, with the goal of guiding future research and improving pilot safety and performance. Methods: The review followed the JBI methodology and adhered to the PRISMA-ScR guidelines. Searches were conducted across eight databases and grey literature, including studies published up to March 31, 2025. A total of 118 studies met the inclusion criteria, encompassing a range of study designs and international contexts. Results: Findings revealed eight key themes: assessment and prediction of G-tolerance, physical conditioning, physiological and anthropometric factors, training and prevention strategies, equipment and technology, physiological effects of high-G exposure, risks and impacts, and external influences. Although AGSM proficiency, cardiovascular reflexes, and muscular strength were consistently associated with improved tolerance, substantial gaps were found in gender representation, longitudinal tracking, and integration of real-time physiological monitoring technologies. Conclusion: This review highlights the multifactorial nature of G-force tolerance and underscores the need for personalized, interdisciplinary approaches in pilot training and assessment. It provides a comprehensive foundation for future research aimed at optimizing high-G performance, with recommendations for standardized protocols, inclusive study populations, and expanded use of wearable monitoring tools.
Copyright (c) 2026 João Bruno, Hugo Sarmento, Raynier Montoro-Bombú https://creativecommons.org/licenses/by/4.0
Considerations and Recommendations for the Development or Enhancement of Undergraduate and Postgraduate Degrees in Strength and Conditioning
This paper consolidates existing literature into 10 research-informed considerations and recommendations for developing or enhancing undergraduate and postgraduate strength and conditioning (S&C) degrees in the United Kingdom. It is hoped these can inform discussions concerning the relevance, quality, and success of S&C degrees across stakeholder groups (professional associations, employers, degree representatives, and students/graduates) and support academic institutions and policymakers to further enhance S&C curricula.
Copyright (c) 2026 Anthony Weldon, Kevin Till, Jonathan Hughes, Ibrahim Akubat, James Keenan, Andrea Cameron, Anthony Turner https://creativecommons.org/licenses/by/4.0
Hitting the Brakes in Soccer: Individualised Thresholds for Assessing High-Intensity Decelerations during Matches
There is currently a lack of understanding surrounding how to quantify high-intensity deceleration actions in soccer. Therefore, this study sought to compare the use of arbitrary (ARB) and individualised (IND) high-intensity deceleration thresholds when examining the most demanding passages of play (MDP) and full matches. Fourteen male soccer players (age = 19.44 ± 1.13 yrs.; mass = 79.14 ± 7.88 kg; height = 184.16 ± 5.00 cm) were monitored during competitive matches using global positioning systems (WIMU Pro, RealTrack System SL, Almeria, Spain). IND thresholds were determined as 75% of a subject's peak deceleration ability from match data. ARB values were set as > 4m/s2 with the differences between these high-intensity deceleration thresholds analysed. ARB thresholds resulted in significantly (p < 0.01) larger distance and count metrics compared to IND during both MDP and full matches. These findings highlight the notable differences between ARB and IND high-intensity deceleration thresholds in matches. Thus, it is recommended a modified IND threshold approach is used when analysing the high-intensity deceleration demands of matches and MDP. Practitioners may be inclined to monitor high-intensity decelerations using IND thresholds, as is suggested when measuring other locomotor tasks during soccer training and matches.
Copyright (c) 2026 Liam Moore, Ben Drury, Andrew Hearn https://creativecommons.org/licenses/by/4.0
Exploring Strength and Conditioning Coaches’ and Stakeholders’ Perceived Value of A Workshop for Learning Psychosocial Coaching Competencies
Commonly used since at least the middle of the 20th century, action research can bridge the gap between science and practice, but within the field of strength and conditioning (S&C), it is a novel research approach. The education and development of S&C practitioners is essential to their understanding of evidence-informed practice and the application of knowledge to improve athletic performance, fitness, and other outcomes, including athlete-centered outcomes, such as well-being. Using a novel, multi-method action research approach, the purpose of this study was to understand S&C stakeholders’ perceived value of learning psychosocial S&C coaching knowledge. In collaboration with the United Kingdom S&C Association (UKSCA), we designed, delivered, and assessed a workshop that included modules on psychological, pedagogical, philosophical, and sociocultural S&C psychosocial coaching competencies. A total of 11 UKSCA participants, including 6 S&C coaches (5 men, 1 woman) and 5 stakeholders (3 men, 2 women), between 38-57 years of age, attended one of the two workshops. Multiple learner-centered activities were completed in the workshop, and then, participants completed data collection methods, including reflection grids and semi-structured interviews. Researchers performed a thematic analysis on the interviews, reflection grids, and field notes that resulted in two overarching themes: participants’ learning and instructional approaches used in the workshop. Participants perceived value from the content and instructional approach used in the workshop, while expressing challenges and recommendations for improvement. This original action research study advances the knowledge about S&C through a novel methodological approach and the education of S&C stakeholders’ psychosocial competencies.
Copyright (c) 2026 Dr. Brian T. Gearity, Dr. Bettina Callary, Mrs. Kimberley Eagles, Dr. Chris Szedlak https://creativecommons.org/licenses/by/4.0
A Framework Guide for the Selection of External Load Metrics in Ice Hockey
External workload monitoring has become commonplace in many sports, with staff looking to leverage the information gained to manipulate practice volume and intensity, hoping to maximize player readiness, minimize fatigue, and reduce the risk of injuries. However, with the increase in availability of technology to facilitate this, practitioners are faced with an overwhelming selection of metrics to choose from. Collinearity, contradiction and the accurate quantification of relative metrics risk creating confusion, and therefore it may benefit practitioners to have some guidance to help in the process of metric selection. This framework aims to provide clarity in the underpinning theory, history and development of external workload monitoring practice, a series of questions for reflective practitioners to consider, and evidence-based practical suggestions for its use.
Copyright (c) 2026 Steven Nightingale, Jonathan Hughes, Mark De Ste Croix, Craig Pfeifer https://creativecommons.org/licenses/by/4.0
Effects of Load on Lower Extremity Joint Kinetics and Kinematics during Hexagonal Barbell Jump Squats
Strength and conditioning coaches often recommend athletes perform loaded jumps with an external load that maximizes peak power output to improve performance. However, there is debate regarding the training load that maximizes acute total body power, and power at individual lower extremity joints. The purpose of this study was to investigate lower extremity kinetic and kinematic variables across a spectrum of loads during jump squats using a hexagonal barbell. Participants performed jumps with a range of loads from 10% to 60% of hexagonal barbell deadlift estimated 1-repetition maximum (e1RM), as well as an unloaded countermovement jump. Using cameras and force plates, lower extremity angles, velocities, moments, powers, as well as total body power, were assessed for each jump. As load increased, there was a decrease in power at the total body level and the hip, but ankle power increased. All joint moment magnitudes increased with load, and flexion angle and velocity at the hip and knee decreased with load. Results suggest that increasing load impacts kinetic and kinematic variables and alters the jumping task, and that the majority of these changes occur when loading exceeds approximately 20-30% 1RM. Further, knee kinetics measures were most strongly related to total body power.
Copyright (c) 2026 Jacob F. Remmert, Abigail K. Salvadore, Adam E. Jagodinsky, Marcel Lopes dos Santos, Michael R. Torry https://creativecommons.org/licenses/by/4.0
Stakeholders Perceptions of Undergraduate and Postgraduate Strength and Conditioning Education in the United Kingdom: A Survey Study
The number of strength and conditioning (S&C) degrees in the United Kingdom has grown alongside the discipline’s popularity. The design and development of these degrees are influenced by various stakeholders, including S&C association representatives, potential employers, degree representatives, students, and graduates. Prior to this study, the collective perceptions of these stakeholders regarding UK S&C degrees had not been researched. This study filled this gap by reporting on the results of 73 participants who completed a one-time anonymous survey, consisting of six sections: (a) background information, (b) degree endorsement, recognition, and accreditation, (c) course structure, (d) placements, (e) module topics, and (f) further information. Frequency analysis was employed for fixed-response questions and thematic analysis for open-ended questions. Participants valued S&C associations and their role in providing degree endorsements, recognitions, and accreditations as they demonstrate quality assurance and alignment with industry standards. However, they felt that professional qualifications from these associations should be more integrated into degree programmes. Regarding degree content and structure, participants agreed that undergraduate degrees should focus on foundational knowledge (e.g., physiology), while postgraduate degrees should cover specialised S&C content and applied practice (e.g., placements). However, some differences in opinion were observed concerning module topics, with participants lacking interest in research-based modules, despite being common, especially at postgraduate level. Placements were considered very important for gaining authentic practical experience, with most participants recommending they be compulsory. Although, flexibility was recommended for students with existing industry experience. These findings provide valuable and needed insights into current perceptions of UK S&C degrees, which may inform stakeholders decisions and practices, lead to closer alignment between stakeholder groups, and create beneficial changes for UK S&C degrees.
Effects of Optimum Power Load vs Mixed Model Training Methods on Lower Limb Strength and Dynamic Performance in Female Athletes
Training with optimum power load (OPL) was shown to result in improved lower limb strength. However, recent study has recommended using the mixed model training (MMT) method which involves frequent varying of training loads. As the training adaptations to OPL and MMT training methods have not been directly compared, hence, the purpose of this study was to compare the effects of OPL and MMT on lower limb neuromuscular adaptations. Seventeen female athletes (age: 22±2.9 years, height: 162.7±5.2 cm, bodyweight: 60.5±9.6 kg) were randomly assigned to either MMT or OPL training (OPLT) group. Both groups performed similar training program twice a week for six weeks. However, MMT performed the loaded CMJ exercise at -15-20% and +20-25% of OPL, while OPLT performed it at OPL. Pre- and post-test included CMJ, 5-0-5 change of direction test (505 COD), 20-m sprint and isometric mid-thigh pull (IMTP). Both groups showed significant improvement in CMJ height (MMT: P=0.025, g=0.48, OPLT: P=0.003, g=0.72), 505 COD (MMT: P<0.001, g=1.12, OPLT: P=0.006, g=0.36), 20-m sprint (MMT: P<0.001, g=0.65, OPLT: P=0.002, g=0.28), IMTP peak force (MMT: P<0.001, g=0.66, OPLT: P<0.001, g=0.46) and IMTP force at 100 ms (MMT: P=0.019, g=0.66, OPLT: P=0.001, g=0.60). Only MMT significantly improved CMJ mean propulsion force (P=0.004, g=0.34), a variable that contributes to greater jump height. While OPLT resulted in greater effect for CMJ height, MMT resulted in greater effect for 505 COD, 20-m sprint and IMTP performance. These findings suggest that frequent varying of resistance may induce greater neuromuscular adaptations.
Copyright (c) 2026 Terence Kwee Hao Chua, Pui Wah Kong, Danny Lum https://creativecommons.org/licenses/by/4.0
Test Re-Test Reliability of Countermovement Jump Testing in Academy Rugby League Environments: Establishing Thresholds for Minimum Detectable Change to Guide Longitudinal Development
League wide profiling is well established in rugby league academy pathways, however the understanding of between-session reliability of assessments completed in applied settings is unknown. This study aimed to determine the between-session reliability of force-time characteristics of the countermovement jump (CMJ) in academy rugby league players. Forty-one academy rugby league players performed three separate CMJ trials on two occasions, separated by 48 hours prior to their resistance training session. Between session reliability was determined by calculating the intraclass correlation coefficient (ICC) and coefficient of variation (CV) with 95% confidence intervals, standard error of measurement (SEM) and minimal detectable change (MDC) from the mean of three trials. Analysis reported moderate to excellent reliability (ICC-95 ≥ 0.5) for 33 out of 37 variables for profiling lower body ballistic force capabilities. Jump height and jump momentum reported good to excellent reliability (ICC-95 = 0.78, CV = 6.64% and ICC-95 = 0.90, CV = 3.58% respectively). League wide profiling assessments undertaken within club environments result in reliable insights of CMJ performance and associated force-time characteristics. Although reliable, future improvements to league wide profiling protocols should remove the club environment as a factor with centralised testing at a singular time in the season to improve data quality of large sample normative datasets.
Copyright (c) 2026 Thomas Shaw, Sean Scantlebury, Sam Wild, Peter Mundy, John McMahon, Kevin Till, Ben Jones, Cameron Owen https://creativecommons.org/licenses/by/4.0
Coaching Insights into Pickup Acceleration
In team sports, sprint acceleration from a moving start, or, in coaching terminology, “pickup acceleration”—is a critical, yet different, skill that occurs more frequently than acceleration from a static start. Despite its importance, pickup acceleration remains underexplored compared to traditional sprint mechanics, which primarily focus on stationary starts. Given the paucity of research, a practice-based evidence approach was employed in this study, gathering insights from expert coaches (N = 13, coaching collegiate, professional, Olympic, or elite high school athletes) to identify the essential physical and technical attributes for enhancing pickup acceleration performance. The surveyed coaches identified lower body force and power production (54%), lower body elasticity and stiffness (38%), hip and ankle range of motion (15%), coordination (38%), and core rotational strength and stability (31%) as essential physical qualities for pickup acceleration proficiency. From a technical perspective, the change in center of mass height (31%) and center of mass angle (46%), anterior touchdown distance, and shin angle (23%), hip separation angle (23%), and optimization of step kinematics (step length and step frequency; 31%) were thought crucial to maximizing acceleration and efficiency. Additionally, distinctions were noted between acceleration from walking versus jogging starts, with each entry type requiring specific adjustments in force application and body alignment. Understanding the determinants and how to assess pickup acceleration can help delineate between track speed and sports speed, enabling coaches to tailor pickup acceleration training for improved performance in terms of sport specificity.
Copyright (c) 2026 Mark Pryer, Prof. John Cronin, Dr. Jono Neville, Chris Korfist, Dr. Aaron Uthoff https://creativecommons.org/licenses/by/4.0
The Relationship Between the Jiu Jitsu Anaerobic Performance Test and Physiological Markers in Trained Jiu Jitsu Practitioners
Jiu Jitsu relies on aerobic and anaerobic energy systems. A relationship has been demonstrated between the Jiu Jitsu Anaerobic Performance Test (JJAPT) and anaerobic performance. The relationship between the JJAPT and aerobic performance has yet to be quantitatively defined. The purpose of this study was to determine if there is a relationship between the JJAPT and maximum oxygen uptake and ventilatory threshold (VT). Twenty-five Jiu Jitsu subjects participated in two test sessions a minimum of 48 hours apart. During one test session, descriptive statistics were collected, a self-guided treadmill warm-up was completed, followed by the Bruce graded exercise protocol. Ventilatory threshold was determined by computer plotting VO2peak and ventilation onto a line chart and confirmed by two researchers. Ventilatory threshold percentage was calculated by hand. The second test session included a JJAPT familiarization warm up and the JJAPT. Pearson correlation was used to determine the relationship between the JJAPT and VO2peak and between the JJAPT and VT. The main findings revealed a significant moderate positive correlation between VO2peak and the JJAPT, (r = 0.40, p = 0.025). Research has shown that Jiu Jitsu has dispersed lower intensity aerobic periods with more reliance on the anaerobic system. The moderate correlation with VO2peak is consistent with the energy system requirements for Jiu Jitsu. This study, in combination with previous studies, indicates the JJAPT provides reliable measures of Jiu Jitsu competition performance. It’s been concluded that the JJAPT could be used to evaluate BJJ athletes and track performance improvements.
Aerobic relationship in Jiu Jitsu Anaerobic Performance Test
Copyright (c) 2026 Renee Peveler, Justin Kilian, Will Peveler https://creativecommons.org/licenses/by/4.0
The Reliability and Validity of Isometric Midthigh Pull Measures Obtained from a Portable Isometric Dynamometer
The purpose of this investigation was to establish the reliability and concurrent validity of measures of peak and early force production obtained from a portable isometric dynamometer (PID). Twenty resistance trained males completed one familiarization and two isometric mid-thigh pull testing sessions separated by 48-72 hrs. During testing sessions data was simultaneously collected from the PID and force plates (FP) both sampling at a frequency of 1000 Hz. Measurements of peak force (PF) and force at 100 ms (Force100) and 200 ms (Force200) obtained from both the PID and the FP demonstrated acceptable reliability (ICC’s = 0.793-0.966; CV% = 2.7-9.2%). However, PF was significantly and meaningfully greater (P < 0.001; d = 1.00) 1.27% greater when obtained from the FP compared to the PID. In contrast, Force100 obtained from FP was significantly lower to that obtained from PID by 229% (P < 0.001; d =3.96). Similarly, Force200 obtained from FP was significantly lower to that obtained from PID by 38.87% (P < 0.001; d = 1.43). Whilst the measures of force production obtained from the PID was shown to have acceptable reliability they displayed questionable validity, particularly with respect to measures of early force production.
Sport Science; Strength and Conditioning
Copyright (c) 2025 Danny Lum, Lachlan P. James, Luke Stutter, Scott Talpey https://creativecommons.org/licenses/by/4.0
Power! A Field Based Testing Resource for Strength & Conditioning Personnel
Power may be the most vital physical trait towards successful sport performance. Whether competing in team sports such as basketball and rugby; individual sports including track and field events, tennis, and golf; endurance based events encompassing cross country skiing, marathon running, and long distance swimming; or even tactical occupations, power development and maintenance is crucial to an athletes’ success. The specific power component most vital to success should be identified, monitored, and tested to ensure continued development and/or maintenance throughout a competition calendar. By conducting a needs analysis, the specific contributions of power to a given sport can be determined. Equally important as knowing how to develop power, is also knowing what economic field based tests are available to accurately assess athletic development. The purpose of this article is to provide strength and conditioning coaches (SCC) across numerous levels/populations and having various levels of funding, with a brief overview, categorization and coaching resource for the vast array of field testing methods available to assess and monitor whole, upper, and lower body power.
Copyright (c) 2025 Ian Bonder, Dr. Mike Waller, Marc Tangeman, Dr. Andrew Shim https://creativecommons.org/licenses/by/4.0
Flywheel Resistance Training for Anterior Cruciate Ligament Rehabilitation
The tearing or rupturing of the anterior cruciate ligament (ACL) has become an increasingly common injury in athletes, particularly in sports that require sharp, pivoting movements and sports that have high deceleration and landing demands. Optimizing each stage of rehabilitation post ACL reconstruction (ACLR) is crucial for successful recovery and the return-to-play of an athlete. Researchers have highlighted the importance of deceleration training and the role of increased eccentric force production and the ability to attenuate rapid braking forces prior to an athletes return-to-sport. There are many training methods that can provide this eccentric overload; however, the focus of this review is on the utility of flywheel resistance training (FRT) during ACL rehabilitation. An overview of the literature that has determined the effects of FRT on ACL rehabilitation post ACLR is discussed, including the current loading parameters, and limitations of the research. A new perspectives of late-stage ACL rehabilitation with FRT is then proposed, with practical examples provided.
Multidisciplinary Perspectives on Injury Prevention, Rehabilitation, and Performance in Sport
Copyright (c) 2026 Margaret Michalak, Dr. Chloe Mihi Ryan, Dr. Alex Ehlert, Dr. John Cronin https://creativecommons.org/licenses/by/4.0
A Retrospective Self-Reported Audit of Injuries Amongst Grappling Athletes Competing in the United Kingdom
Purpose: This study aimed to estimate the incidence, prevalence, type, and mechanism of injuries among grappling athletes in the United Kingdom (UK) across the following disciplines: Brazilian Jiu-Jitsu (BJJ), Judo, Catch Wrestling, Sambo, and Mixed Martial Arts (MMA). Methods: A retrospective, self-reported survey, delivered via JISC online survey software, was used to record the following information for all injuries sustained over the previous 12-month period: mechanism of injury, environment, severity, recurrence and body region. Additionally, injury diagnosis was reported where possible. Injury incidence for training exposure was calculated based on hours trained per week, while competition exposure was based on the number of bouts participated in during the year. One variable chi-square tests (X2) were used to calculate if observed values were significantly different from expected values. Results: A total of 341 grappling athletes, 243 males and 97 females, with one participant preferring not to state gender (32 ± 9.3 years), completed the study over a 3-month period. The competition incident rates (IR) (24.16/1000 AE) were significantly higher than training (2.97/1000 AE). The knee was the most frequently injured site (24.5%). Ligament sprains were the most commonly diagnosed injury (24.3%). Most injuries occurred during practice sparring (65.8%), with the leading mechanisms being submission attempts and takedowns. Major injuries (>28 days recovery) accounted for 49.5% of all cases. BJJ exhibited the highest injury rate (3.49/1000 AE); patterns varied by discipline and gender. Conclusion: Grappling sports pose a substantial risk of injury, particularly to the knee. Structured training, medical support, and tailored injury risk reduction programs should now be explored to enhance athlete safety.
Copyright (c) 2026 Jonathan Bell, Eleanor Travis, Ashley Jones https://creativecommons.org/licenses/by/4.0
Development of an Independent Regulatory Council for the International Qualification Framework: International Universities Strength and Conditioning Association Position Statement
The establishment of the International Qualification Framework (IQF) represented a seminal advancement towards standardising education and certification levels in the profession of strength and conditioning (S&C). By providing a standardised and internationally unified structure, the IQF directly addresses the long-standing disparities and inconsistencies noted in education and qualification recognition globally. However, the credibility and effectiveness of such a global qualification framework depends upon robust policies and detailed independent regulatory oversight. The IQF Independent Regulatory Council (IQF-IRC) has therefore been established as an autonomous body, specifically designed to oversee the IQF including its education, accreditation, and certification processes. This position statement outlines the governance structure, core responsibilities, professional relevance, and strategic objectives of the IQF-IRC. It will also discuss the benefits of voluntary alignment by global S&C organisations, ultimately fostering a cohesive and universally accepted education and accreditation system that can be presented to the wider industry and public.
Copyright (c) 2025 Andrew Langford, Aden Flannagan, Stephen P. Bird, Paulo Marchetti, Timothy J. Piper, David Morley https://creativecommons.org/licenses/by/4.0
Position-Specific Benchmarks for Jump and Reach Metrics in the National Basketball Association Draft Combine
This study analysed data from the NBA draft combine and aimed to establish position-specific normative data for jump and reach performance to support coaches in better assessing the jumping ability of basketball players. Data on body height with shoes, standing reach (STReach), vertical jump reach (VJReach), and running jump reach (RJReach) were obtained from publicly available sources for 1,048 players who participated in the NBA draft combine between the 2004-05 and 2022-23 seasons. Vertical jump height (VJHeight), running jump height (RJHeight), and run-up effect (RE) were calculated. These variables were then compared across five playing positions; point guard, shooting guard, small forward, power forward, and center and position-specific percentile scores were generated to create normative data. Results showed that RJReach significantly increased from guards to centers (p < .05), primarily reflecting positional differences in anthropometry. Notably, guards demonstrated significantly higher VJHeight, RJHeight, and RE (p < .05) compared to power forwards and centers, indicating that shorter players may compensate for their height through enhanced vertical jump and RE. Furthermore, height and STReach progressively increased from guards to centers, highlighting the contribution of anthropometric, non-trainable characteristics. VJReach and RJReach increased across positions, and this increase was significant between all positions but power forwards and centers. RE was higher in guards and forwards than in centers. These results imply that RE may capture unique, trainable aspects of jump performance. This study presents position-specific benchmarks for jumping ability, offering strength and conditioning coaches practical reference values to assess players’ strengths and weaknesses and to design tailored training programs.
Copyright (c) 2026 Hiroki Ogata, Henderson Frederick, Daichi Yamashita https://creativecommons.org/licenses/by/4.0
Concurrent Validity and Reliability of the My Jump Lab Smartphone Application for Break Point Angle Assessment in the Nordic Hamstring Exercise
The Nordic Hamstring Exercise is widely used to prevent muscle strain injuries. Although isokinetic dynamometry is considered a gold standard for assessment, it is often impractical in many settings, due to several reasons. A cost-effective alternative for physical evaluations of the same muscle could be Smartphone-based, which have greatly increased in recent years due to technological advancements. This study aims to assess the concurrent validity and inter-rater reliability of the My Jump Lab smartphone application in measuring the break point angle (BPA) during the Nordic Hamstring Exercise. Twenty-four healthy participants were recruited for this study and performed five repetitions of the nordic hamstring exercise, while being recorded via smartphone for BPA estimation. The same exercise was compared with kinematic analysis, as reference method. Concurrent validity was assessed by Pearson’s product-moment correlation coefficient and Bland-Altman Plots, while inter-rater reliability was analysed by intraclass correlation coefficient (ICC), coefficient of variation (CV) and standard error of measurement (SEM). Results revealed a very high and significant level of correlation (r > 0.9, p< 0.001) for break point angle measurements, with small proportional bias. The app showed excellent inter-rater reliability (ICC >0.9), with very small variations (CV ≈ 1%) and SEM lower that 1.3 degrees. These outcomes suggest that My Jump Lab is a valid and reliable tool for BPA assessment, that can be used confidently to assess hamstring muscle strain in a simple, portable and practical manner.
Copyright (c) 2025 Amandio Dias, André Gomes, Diogo Nogueira, Leonel Correia, Rodrigo Trindade https://creativecommons.org/licenses/by/4.0
A Comparative Biomechanical Analysis of the Farmers and Zercher Carry Exercises
ABSTRACT The loaded carry is a movement pattern characterized by walking for a set time or distance with an externally applied resistance. The application of an external load alters the body’s biomechanics, creating an environment for potential adaptation and performance enhancement. Further, the location of the load may have additional adaptation implications as a result of center of mass (CoM) changes which may impact body stability. Specifically, a resistance carried anterior to the body as done in the Zercher Carry (ZC), causing a vertical and anterior translation of the CoM, may stimulate different compensatory mechanisms from the Farmers Carry where the load is held at the sides of the body, keeping the CoM in its relative anatomical location. To investigate this, healthy, college aged individuals were recruited and their anthropometric data was captured. Participants were then prepped for surface electromyography with electrodes placed on their dominant side rectus abdominis, external oblique, multifidus, longissimus, upper trapezius, and middle deltoid. Maximal voluntary isometric contractions were performed to standardize muscle activation. Participants were outfitted with inertial measurement units for the trunk and lower limb to capture gait and joint kinematics. One counterbalanced 5-meter walk loaded with 100% fat free mass was completed for each exercise with participants stepping on a force plate halfway to capture single step ground reaction forces (GRF). Data for all variables were compared utilizing a MANOVA. Comparisons between the FC and ZC revealed significant differences (P < 0.05) in muscle activation (e.g., multifidus: FC 12.0 ± 6.7 v. ZC 25.4 ± 13.0), joint kinematics (e.g., lumbar extension: FC -4.4 ± 4.1 v. ZC 2.0 ± 6.5), gait (e.g., stride length: FC 108.1 ± 9.4 v. ZC 101.4 ± 9.4) and GRFs (e.g., anterior GRF: FC 22.3 ± 6.8 v. ZC 17.5 ± 7.4). The differences observed between the ZC and FC as a result of load position may implicate unique adaptation and influence how these exercises should be implemented in resistance training programs.
Copyright (c) 2026 Accalia D. Decker, Justin M. Fagley, Shaylyn A. McNally, Zachary M. Regalski, Kaylee C. Rhinehart, Ava V. Urda, Michael E. Holmstrup, Jeremy R. Dicus https://creativecommons.org/licenses/by/4.0
Measuring Impulse-DSI and its Derivatives Via the Isometric Belt Squat: Assessing Relationships with Sprint Ability Among Division 1 Team Sport Athletes
The dynamic strength index (DSI) is a common athlete profiling tool that has traditionally been derived as the ratio between the peak force in the isometric mid-thigh pull (IMTP) and the countermovement jump (CMJ) to identify ballistic strength deficits. Recently, an impulse-based DSI (iDSI) has been proposed for the relevance of impulse metrics in explosive sports. Furthermore, the isometric belt squat (IBSq) may be a superior alternative to the IMTP for measuring lower-body force potential owing to its removal of the torso and upper limb involvement. This study assessed the reliability of two novel IBSq and CMJ 200ms impulse metrics. Furthermore, we assessed the individual relationships and predictive utility of the DSI derivatives and 40m sprint performance. 43 Division 1 team sport athletes (30 males and 13 females) were recruited. Reliability was assessed using the intraclass correlation coefficient (ICC) and the coefficient of variation (COV). The relationships between DSI and iDSI derivatives, 0-10m, 10-30m, and 30-40m split times were assessed using Pearson’s correlation coefficient and stepwise regression. The IBSq and CMJ impulses demonstrated acceptable reliability (ICC > .93, COV < 9.6%). IBSq and CMJ impulses explained up to 56% of the variance in 0-10m time (p <.002) and up to 49% of the variance in 30-40m time (p <.0001). The IBSq-derived iDSI score may be a reliable and accurate test for predicting sprint performance among Division 1 team sport athletes. Practitioners may monitor iDSI derivatives to enhance training decisions relevant to sprint speed.
Copyright (c) 2026 Matthew Ward https://creativecommons.org/licenses/by/4.0
Physical Profile of Strongman and Strongwoman Athletes
While strongmen and strongwomen are among the strongest athletes in all sports, limited literature is available pertaining to the physical and physiological characteristics of this population, including their vertical jump ability. Thus, the purpose of this study was to profile a cohort of strongman and strongwoman competitors at an international strongman/strongwoman event and measure jump performance differences between competitors (currently active strongmen/strongwomen) and resistance-trained individuals (individuals not strongmen or strongwomen at the event). Twenty-three subjects who attended an international strongman and strongwoman event (age:27.7±5.9 years; weight: 116.3±30.4 kg) volunteered to participate in the present study. Weight, hand length, hand grip strength, self-reported one repetition maximum for common powerlifting exercises, and specific countermovement vertical jump (CMJ) and squat jump (SJ) metrics were analyzed for between-sex differences within the sport. The present study's findings reveal that hand length, hand grip strength, and self-reported one repetition maximum for common powerlifting exercises were significantly higher for strongman competitors. For CMJ and SJ, both relative and absolute mean and peak velocity, force, and power in eccentric and concentric phases were significantly higher for strongman competitors. Contraction times were shorter for strongmen in both CMJ and SJ than strongwomen but were non-significant. Interestingly, the eccentric utilization ratio and the stretch-shortening cycle percentage did not significantly differ between strongman and strongwoman competitors, however, the entire cohort's eccentric EUR was considerably less than 1.2, indicating higher overall strength than ballistic power. The present study was able to profile the physical and jump performance characteristics of strongman and strongwoman competitors.
Copyright (c) 2026 Yang Yang, Quincy Johnson, Nicolas Philipp, Drake Eserhaut, Joe Kenn, Dimitrije Cabarkapa, Andrew Fry https://creativecommons.org/licenses/by/4.0
Fitness Characteristics of the Welsh Rugby Union's Schools and Colleges League Players
Purpose: The study aimed to establish physical fitness standards for the 16–18-year-old rugby union players who compete in the Welsh Rugby Union’s National Schools and Colleges (WSC) league. Methods: Testing was undertaken at the end of pre-season, by 261 male players (17.0±0.6 years; 85.9±14.7 kg; 179.3±6.3 cm) and included: 40 m sprint, countermovement jump, 10/5 repeated jump, isometric belt squat, isometric hip adductor and abductor strength, 30-15 intermittent fitness test, and eccentric knee flexor strength. Descriptive statistics are reported for the entire sample as well as position groups (forwards and backs) and individual positions. Differences to the sample mean were identified using analysis of means and quantified using Cohen's d effect size. Results: The prop, scrum half, outside half, center, and back three positions had the most notable deviations from the sample means, reflecting their specific roles. Comparisons were made to school and academy players of similar age and to senior professionals, to assess the physical status of the WSC players and determine the gap between competition levels. Except for the 30-15 intermittent fitness test, the WSC data was within previously reported ranges for schoolboy and academy players of similar age. The largest differences between WSC and senior professional players was in body mass and strength variables. Conclusion: This information could be used to support talent identification, player tracking, and for the development of national standards and benchmarks (see supplemental materials).
Copyright (c) 2026 Peter Ashcroft, Kate Williams, William Raymond, Nathan Evans, Rhodri Williams, Ned Patridge, Morgan D Williams https://creativecommons.org/licenses/by/4.0
Profiling the Physical Conditioning Attributes of Young Male Gaelic Football Players: From Adolescence to Adulthood
This study assessed the anthropometry and physical conditioning attributes of young male inter-county (national level) Gaelic football players, comparing possible differences according to age categories (under-14 [U14] to under-21 [U21]) and position. In total, 3547 assessments were undertaken in 2588 players across a 10-year period (2013 to 2023). Assessments included anthropometry (stature, body mass, sum of 3 skinfolds), flexibility (sit and reach test), muscular power (countermovement jump and standing long jump), running speed (5-m and 20-m), muscular endurance (maximum push ups) and aerobic capacity (yo-yo intermittent recovery test level 1 [YYIRT1]). Increases were demonstrated when comparing age categories from U14 to U21 for anthropometry (e.g., height [cm] +5.7%), muscular power (e.g., Standing long jump [cm] +16.1%). running speed (e.g., 5 m speed [s] -4.8% from U14 to U20), running momentum (e.g., 20 m momentum [kg.ms-1] +41.5% from U14 to U20), muscular endurance (push-ups [n] +107.7%), flexibility (sit and reach [cm] +36.0%) and aerobic capacity (YYIRT1 [m] +42.3%). When comparing positions, goalkeepers and midfielders were taller and heavier than backs and forwards, respectively. Additionally, midfielders displayed superior aerobic conditioning when compared with other positions, while goalkeepers displayed significantly lower aerobic conditioning. These findings offer comparative data of young Gaelic football players from varying age categories (U14 to U21) which are further classified according to positions. Practitioners may utilize this data to inform player identification processes, characterize position-specific benchmarks and monitor physiological adaptations in young players.
Copyright (c) 2025 Lorcan Daly, Cathal Cregg, Daniel Forde, Ciarán Catháin, David Kelly https://creativecommons.org/licenses/by/4.0
Strength, Power and Anaerobic Capacities of Male Judo Athletes across Age and Competitive Levels
Purpose: This cross-sectional study evaluated the physiological profiles of judo athletes across age and competitive levels, aiming to identify key physiological determinants of judo success. Methods: Thirty-eight judokas from three age/competitive levels (cadet + junior, non-Olympic senior, and Olympic senior), spanning various weight classes and ages, were assessed for strength, power, and anaerobic qualities. Performance tests included countermovement jump, drop jump, maximal grip strength, and upper body Wingate anaerobic test (WIN) and results were normalized to body mass. Strength values were obtained from the athletes’ self-reported training programs and normalized to competition weight class. Comparisons of the physical measures were made across age/competitive levels and a qualitative evaluation based on success in national vs. international competitions was made within the groups. Results: Significant differences in absolute values were observed between age/competitive level groups; however, most differences disappeared after normalization. The only persistent differences were in relative WIN peak power and relative WIN mean power, which were greater for the senior athletes compared with the cadet + junior group. No significant differences were found between quality levels within the groups. Conclusion: In the within-group analysis, it was not possible to differentiate high vs. low quality level male judo athletes in our cohort. When comparing the three groups, only relative WIN peak and relative mean power were significantly different between groups while other measures lost significance when normalized. This strengthens the notion that anaerobic power and capacity are relevant to judo success.
Copyright (c) 2025 Idan Harat, Dr. Rotem Kislev-Cohen, Dr. David H. Fukuda https://creativecommons.org/licenses/by/4.0