Eccentric Force-Velocity-Load Relationship in Trained Rugby Union Athletes.

ABSTRACT: McNeill, C, Beaven, CM, McMaster, DT, Ward, P, and Gill, N. Eccentric force-velocity-load relationship in trained rugby union athletes. J Strength Cond Res 38(3): 549-555, 2024-The force-velocity relationship is traditionally believed to resemble a hyperbolic shape, known as the "force-velocity curve." However, there is less evidence regarding this relationship during eccentric muscle action in multijoint isotonic exercise, especially in applied settings. The purpose of this study was to investigate the force-velocity-load relationship in an incremental eccentric back squat test. In addition, 37 professional male rugby union athletes were recruited to participate. Separate generalized linear mixed models were used to analyze the effect of barbell load on relative eccentric peak force (REPF), relative eccentric mean force (REMF), eccentric peak velocity (EPV), and eccentric mean velocity (EMV). A significant effect of load ( p < 0.05) was observed for each of the eccentric variables tested. Each increase in barbell load tended to result in a linear increase in REMF and a decrease in EMV and EPV; however, we observed a plateauing effect for REPF as load increased. These results show that for "peak" variables lighter loads produced similar magnitudes of force, but generally moved at higher velocities than heavier loads. These observations suggest that the eccentric force-velocity-load relationship may vary depending on the parameters used. Quantifying rapid, multijoint eccentric performance is justified as it seems to provide valuable insight into individual athletic capability and training program design. Further research may investigate the responsiveness of the qualities to training and the causal nature of eccentric characteristics and athletic performance.

The associations between physical-test performance and match performance in women's Rugby Sevens players.

Evaluating the relationships between physical-test and match performance in team sports could be useful for training prescription and athlete evaluation. Here we investigated these relationships in women's Rugby Sevens. Thirty provincial-representative players performed Bronco-fitness, countermovement-jump, acceleration, speed, and strength tests within two weeks before a two-day tournament. Match-running and match-action performance measures were provided by GPS units and video analysis. Generalised and general linear mixed models were employed to estimate the effect of a two standard-deviation difference in physical-test measures on match measures. Effect magnitudes were assessed via standardisation (using the between-player SD) and, for effects on tries scored, also via match winning (based on simulating matches). Evidence for substantial and trivial true magnitudes was provided by one-sided interval-hypothesis tests and Bayesian analysis. There was good evidence of positive effects of many physical-test measures on match high-intensity running, with large effects for jump height and acceleration. There was some evidence of small-moderate positive effects of speed and Bronco, and of small-moderate negative effects of maximal strength and jump height, on match total running and high intensity changes in speed. The evidence was generally inadequate for associations between physical-test measures and match actions, but there was good evidence of small-large positive effects of back squat and jump height on tries scored. Enhancing players' jump height and back-squat performance might therefore increase the likelihood of match success in women's Rugby Sevens.

Eccentric Force-Velocity Characteristics during a Novel Squat Protocol in Trained Rugby Union Athletes-Pilot Study.

Eccentric strength characteristics have been shown to be important factors in physical performance. Many eccentric tests have been performed in isolation or with supramaximal loading. The purpose of this study was to investigate within- and between- session reliability of an incremental eccentric back squat protocol. Force plates and a linear position transducer captured force-time-displacement data across six loading conditions, separated by at least seven days. The reliability of eccentric specific measurements was assessed using coefficient of variation (CV), change in mean, and intraclass correlation coefficient (ICC). Eccentric peak force demonstrated good ICC (≥0.82) and TE (≤7.3%) for each load. Variables based on mean data were generally less reliable (e.g., mean rate of force development, mean force, mean velocity). This novel protocol meets acceptable levels of reliability for different eccentric-specific measurements although the extent to which these variables affect dynamic performance requires further research.

Survey of Eccentric-Based Strength and Conditioning Practices in Sport.

McNeill, C, Beaven, CM, McMaster, DT, and Gill, N. Survey of eccentric-based strength and conditioning practices in sport. J Strength Cond Res 34(10): 2769-2775, 2020-Eccentric-based training (ECC) has been shown to be an effective training strategy in athletes; however, despite the theoretical benefits, the uptake by practitioners is currently unknown. This study investigated the current ECC strength and conditioning practices that are implemented in the training of athletes. Two hundred twenty-four practitioners were electronically surveyed anonymously with 98 responses available for analysis. Nearly all respondents (96%) had prescribed ECC in the last 24 months. Sport performance (64%), injury prevention (24%), and rehabilitation (8%) were the top-ranked reasons to include ECC. Respondents programmed ECC for strength (35%), hypertrophy (19%), and power (18%). A majority of respondents did not monitor ECC load (58%) or use eccentric-specific testing (75%). Seventeen respondents commented that high-intensity training such as sprinting and change of direction, were avoided during ECC blocks. Eccentric-based training intensity was prescribed as percentage of 1 repetition maximum (34%), rate of perceived exertion (20%), or velocity (16%). Respondents indicated muscle soreness and concurrent high-intensity activities were concerns during ECC but reported not using eccentric monitoring or testing. The efficacy of ECC is well supported, yet there seems to be a lack of defined protocol for integrating ECC research into practice. A greater understanding of eccentric contribution to sport performance and injury prevention may help define testing and monitoring procedures for the prescription of ECC interventions. Practitioners should consider factors such as periodization, soreness, and monitoring when designing ECC programs. The findings of this survey indicate that no uniform strategies exist for the prescription of ECC among experienced practitioners.

Match Demands, Anthropometric Characteristics, and Physical Qualities of Female Rugby Sevens Athletes: A Systematic Review.

Sella, FS, McMaster, DT, Beaven, CM, Gill, ND, and Hébert-Losier, K. Match demands, anthropometric characteristics, and physical qualities of female rugby sevens athletes: A systematic review. J Strength Cond Res 33(12): 3463-3474, 2019-Since the inclusion of rugby sevens in the 2016 Olympic Games, the popularity of women's rugby sevens has grown rapidly worldwide. This systematic review aimed to summarize the scientific literature addressing the match demands, anthropometric characteristics, and physical qualities of female rugby sevens athletes and to highlight differences between competition levels and playing positions. Four electronic databases were searched, as were the reference lists and key journals. Hedges' g effect sizes with 95% confidence intervals were calculated to evaluate differences between elite and nonelite athletes, and backs and forwards. Twenty-seven studies met inclusion criteria and scored 68 ± 13% upon quality assessment. Comparisons between groups were restricted to variables where data were available. Greater running demands and intensities, number of sprints and accelerations, but lower physiological responses characterized international matches compared with nationals. At international level, backs demonstrated greater running demands and intensities, number of sprints, and physiological responses than forwards. Elite athletes were leaner, taller, and displayed superior physical qualities (e.g., maximal speed, power, upper-body strength, and aerobic capacity) compared with nonelite athletes. At elite level, forwards were heavier and displayed greater upper-body strength, whereas backs showed greater acceleration and maximal speed abilities. The specific match demands and physical requirements of female rugby sevens athletes competing at different playing levels and playing positions must be considered for developing effective training programs.

Eccentric Training Interventions and Team Sport Athletes.

Eccentric resistance training has been shown to improve performance outcomes in a range of populations, making it a popular choice for practitioners. Evidence suggests that neuromuscular adaptations resulting from eccentric overload (EO) and accentuated eccentric loading (AEL) methods could benefit athletic populations competing in team sports. The purpose of this review was to determine the effects of eccentric resistance training on performance qualities in trained male team sport athletes. A systematic review was conducted using electronic databases PubMed, SPORTDiscus and Web of Science in May 2019. The literature search resulted in 1402 initial articles, with 14 included in the final analysis. Variables related to strength, speed, power and change of direction ability were extracted and effect sizes were calculated with a correction for small sample size. Trivial, moderate and large effect sizes were reported for strength (-0.17 to 1.67), speed (-0.08 to 1.06), power (0.27 to 1.63) and change of direction (0.48 to 1.46) outcomes. Eccentric resistance training appears to be an effective stimulus for developing neuromuscular qualities in trained male team sport athletes. However, the range of effect sizes, testing protocols and training interventions suggest that more research is needed to better implement this type of training in athletic populations.

Match analysis in Rugby Union: performance indicators of Rugby Championship and Super Rugby teams.

BACKGROUND: A number of key performance indicators (KPIs) have been found to discriminate between winning and losing performances in Rugby Union competitions. This study aimed to investigate the KPIs of winning and losing teams during recent Rugby Championship and Super Rugby seasons. METHODS: Data from 139 matches during the 2014-2015 Rugby Championship and 2015 Super Rugby were extracted from the SANZAAR website and retrospectively analyzed. Seventeen KPIs were used to describe the differences between winning and losing performances in different aspects of the game. Magnitude-based inferences, effect size with 90% confidence interval, percentage changes, and statistical significance were calculated. RESULTS: Winning teams during the Rugby Championship were most likely to score more tries, and very likely to gain more meters, beat more defenders, and miss less tackles compared to losing teams. In Super Rugby, winning teams were most likely to score more tries, execute more clean breaks, kicks in play and very likely to win more turnovers and concede a lower number of turnovers. The number of tackles made, and meters gained were also likely higher in Super Rugby winning teams compared to the losing counterparts. CONCLUSIONS: A limited number of KPIs differentiated were observed between winning and losing performances in the Rugby Championship, whereas numerous attacking and defensive KPIs were found to discriminate between winning and losing teams during Super Rugby. The method of data extraction, analysis and interpretation used herein could assist with game strategies and in turn better prepare teams and players for competition.

The Efficacy of Wrestling-Style Compression Suits to Improve Maximum Isometric Force and Movement Velocity in Well-Trained Male Rugby Athletes.

Purpose: The prevalence of compression garment (CG) use is increasing with athletes striving to take advantage of the purported benefits to recovery and performance. Here, we investigated the effect of CG on muscle force and movement velocity performance in athletes. Methods: Ten well-trained male rugby athletes wore a wrestling-style CG suit applying 13-31 mmHg of compressive pressure during a training circuit in a repeated-measures crossover design. Force and velocity data were collected during a 5-s isometric mid-thigh pull (IMTP) and repeated countermovement jump (CMJ), respectively; and time to complete a 5-m horizontal loaded sled push was also measured. Results: IMTP peak force was enhanced in the CG condition by 139 ± 142 N (effect size [ES] = 0.36). Differences in CMJ peak velocity (ES = 0.08) and loaded sled-push sprint time between the conditions were trivial (ES = -0.01). A qualitative assessment of the effects of CG wear suggested that the likelihood of harm was unlikely in the CMJ and sled push, while a beneficial effect in the CMJ was possible, but not likely. Half of the athletes perceived a functional benefit in the IMTP and CMJ exercises. Conclusion: Consistent with other literature, there was no substantial effect of wearing a CG suit on CMJ and sprint performance. The improvement in peak force generation capability in an IMTP may be of benefit to rugby athletes involved in scrummaging or lineout lifting. The mechanism behind the improved force transmission is unclear, but may involve alterations in neuromuscular recruitment and proprioceptive feedback.

A Brief Review of Handgrip Strength and Sport Performance.

Cronin, J, Lawton, T, Harris, N, Kilding, A, and McMaster, DT. A brief review of handgrip strength and sport performance. J Strength Cond Res 31(11): 3187-3217, 2017-Tests of handgrip strength (HGS) and handgrip force (HGF) are commonly used across a number of sporting populations. Measures of HGS and HGF have also been used by practitioners and researchers to evaluate links with sports performance. This article first evaluates the validity and reliability of various handgrip dynamometers (HGD) and HGF sensors, providing recommendations for procedures to ensure that precise and reliable data are collected as part of an athlete's testing battery. Second, the differences in HGS between elite and subelite athletes and the relationships between HGS, HGF, and sports performance are discussed.

Effects of a Six-Week Hip Thrust vs. Front Squat Resistance Training Program on Performance in Adolescent Males: A Randomized Controlled Trial.

Contreras, B, Vigotsky, AD, Schoenfeld, BJ, Beardsley, C, McMaster, DT, Reyneke, JHT, and Cronin, JB. Effects of a six-week hip thrust vs. front squat resistance training program on performance in adolescent males: A randomized controlled trial. J Strength Cond Res 31(4): 999-1008, 2017-The barbell hip thrust may be an effective exercise for increasing horizontal force production and may thereby enhance performance in athletic movements requiring a horizontal force vector, such as horizontal jumping and sprint running. The ergogenic ability of the squat is well known. The purpose of this study was to compare the effects of 6-week front squat and hip thrust programs in adolescent male athletes. Vertical jump height, horizontal jump distance, 10- and 20-m sprint times, and isometric midthigh pull peak force were among the measured performance variables, in addition to front squat and hip thrust 3 repetition maximum (3RM) strength. Magnitude-based effect sizes revealed potentially beneficial effects for the front squat in both front squat 3RM strength and vertical jump height when compared with the hip thrust. No clear benefit for one intervention was observed for horizontal jump performance. Potentially beneficial effects were observed for the hip thrust compared with the front squat in 10- and 20-m sprint times. The hip thrust was likely superior for improving normalized isometric midthigh pull strength and very likely superior for improving hip thrust 3RM and isometric midthigh pull strength. These results support the force vector theory.

Reliability, Validity and Usefulness of 30-15 Intermittent Fitness Test in Female Soccer Players.

PURPOSE: The aim of this study was to examine the reliability, validity and usefulness of the 30-15IFT in competitive female soccer players. METHODS: Seventeen elite female soccer players participated in the study. A within subject test-retest study design was utilized to assess the reliability of the 30-15 intermittent fitness test (IFT). Seven days prior to 30-15IFT, subjects performed a continuous aerobic running test (CT) under laboratory conditions to assess the criterion validity of the 30-15IFT. End running velocity (VCT and VIFT), peak heart rate (HRpeak) and maximal oxygen consumption (VO2max) were collected and/or estimated for both tests. RESULTS: VIFT (ICC = 0.91; CV = 1.8%), HRpeak (ICC = 0.94; CV = 1.2%), and VO2max (ICC = 0.94; CV = 1.6%) obtained from the 30-15IFT were all deemed highly reliable (p > 0.05). Pearson product moment correlations between the CT and 30-15IFT for VO2max, HRpeak and end running velocity were large (r = 0.67, p = 0.013), very large (r = 0.77, p = 0.02) and large (r = 0.57, p = 0.042), respectively. CONCLUSION: Current findings suggest that the 30-15IFT is a valid and reliable intermittent aerobic fitness test of elite female soccer players. The findings have also provided practitioners with evidence to support the accurate detection of meaningful individual changes in VIFT of 0.5 km/h (1 stage) and HRpeak of 2 bpm. This information may assist coaches in monitoring "real" aerobic fitness changes to better inform training of female intermittent team sport athletes. Lastly, coaches could use the 30-15IFT as a practical alternative to laboratory based assessments to assess and monitor intermittent aerobic fitness changes in their athletes.

Force-Velocity-Power Assessment in Semiprofessional Rugby Union Players.

There is a constant and necessary evolution of training and assessment methods in the elite contact sports; as is required to continually improve the physical qualities of these respective athletes to match the growing sport and position-specific performance demands. Our aim was to examine the differences between ballistic upper body performance profiles and maximum upper body strength of elite rugby union forwards and backs. Twenty semiprofessional male rugby union players (age = 21.1 ± 3.0 years; mass = 94.9 ± 9.7 kg) were assessed for maximum bench press strength (1RM bench press = 121.3 ± 21.8 kg) and maximum throw power (Pmax), force (Fmax), and velocity (V[Combining Dot Above]max) from an incremental relative load testing protocol (15, 30, 45, 60, and 75% 1RM). Player rankings were also included to identify individual strength and weaknesses. The forwards were moderately stronger (effect size [ES] = 0.96; p = 0.01), produced significantly greater Fmax (ES = 1.17-1.41; p = 0.01) and were more powerful (ES = 0.57-0.64; p < 0.43) than the backs. V[Combining Dot Above]max differences were trivial to small (ES = -0.32 to -0.65; p > 0.15). There were inherent differences in strength and Fmax between the forwards and backs most likely because of the physical demands of these respective positions. Improvements in upper body strength may in turn improve ballistic force and power production, but not necessarily velocity capabilities. From the Fmax and V[Combining Dot Above]max observations, the forwards seem to be more force dominant and the backs more velocity dominant. Pmax, Fmax, and V[Combining Dot Above]max may be used to highlight proficient and deficient areas in ballistic upper body performance; the individual rankings could be further used to identify and possibly rectify individual deficiencies.