Post-Activation Performance Enhancement of Punch Force and Neuromuscular Performance in Amateur Boxing: Toward a More Individualized and "Real-World" Approach.

ABSTRACT: Finlay, MJ, Greig, M, Bridge, CA, and Page, RM. Post-activation performance enhancement of punch force and neuromuscular performance in amateur boxing: Toward a more individualized and "real-world" approach. J Strength Cond Res 38(6): 1063-1071, 2024-Previous research on post-activation performance enhancement has been applied in several sporting settings, although this is lacking in a boxing setting. This study explored the effectiveness of 2 upper-body conditioning activities in improving punch-specific performance during an amateur boxing-simulated bout. On 3 separate occasions, 10 male senior elite amateur boxers performed the following conditioning activities before a boxing-specific simulation protocol: isometric (ISO) punch, elastic resistance (ER) punch, and a control trial. Boxers performed maximal punches against a vertically mounted force plate, and countermovement jumps (CMJ) at baseline, before round 1, after each round, and 4 minutes after the simulation. Both conditioning activities, but not the control trial, produced small worthwhile increases (effect size ≥ 0.20; equal to or greater than the smallest worthwhile change) in punch force, although worthwhile increases in rate of force development were limited to the cross during the ISO trial. No group-based improvements in CMJ performance were observed. Individual analysis revealed that 6 boxers improved punch-specific performance to the greatest extent in the ISO trial; in contrast, only 1 boxer did so in the ER trial. Three boxers exhibited similar performance increases across trials. In conclusion, both conditioning activities may be applied to an amateur boxer's warm-up to acutely enhance punch-specific performance. The ISO conditioning activity seems most effective; however, the interindividual variability suggests a need for protocols to be individualized to each athlete. The conditioning activities in the present study may be applied to sparring, competitive bouts, or to other combat sports.

Test-retest reliability and sensitivity of senior elite amateur boxers maximal punch force, as quantified by a vertically mounted force plate.

An ecologically valid, reliable and sensitive method of quantifying punch force variables would be useful for coaches and practitioners monitoring combat-specific performance. The present study utilised a vertically mounted force plate to quantify the peak punch force and rate of force development (RFD) of amateur boxers. Ten male senior elite amateur boxers performed maximal jab, cross, and hook punches across two separate days. The force plate showed excellent within-day and good-to-excellent between-day reliability for peak punch impact force and RFD (ICC 0.89-0.99). The CV% for all punch force variables were similar on day 1 (3-9%) and day 2 (4-10%). Standard error of measurement (SEM) and smallest worthwhile changes (SWC) revealed the force plate can detect small-to-moderate changes in punch performance. The greatest impact forces and RFD were found in the rear hook (2624 ± 581 N, 296448 ± 101823 N.s-1), followed by the lead hook (2524 ± 532 N, 256813 ± 81735 N.s-1), cross 2425 ± 545 N, 193004 ± 62671 N.s-1) and jab (1645 ± 537 N, 116675 ± 41577 N.s-1). The vertically mounted force plate is a reliable and sensitive test of punch performance, thus may be useful in determining the efficacy of training interventions.

The Impact of 120 Minutes of Soccer-Specific Exercise on Recovery.

Purpose: The extra-time (ET) period of soccer is competed during fixture congested schedules with often limited recovery time between matches. The aim of this study was to assess muscle damage recovery following 90- and 120-min (i.e., incorporation of ET) of simulated soccer match-play. Methods: Twelve semiprofessional soccer players completed 90 and 120-min treadmill-based soccer-specific exercise in a counterbalanced order. Creatine kinase (CK), creatinine, urea, aspartate aminotransferase, perceived muscle soreness, pain pressure threshold, reactive strength index, countermovement jump height, and isokinetic strength assessments of eccentric knee flexors at 60, 180 and 270 deg‧s-1 were taken at baseline and immediately-, 24, 48 and 72-hr post-exercise to assess recovery. Results: No significant between-trial interactions except for CK were found. Pairwise comparisons detected a 53% increase in CK at 24-hr (455 ± 29 µâˆ™L-1) following 120-min of simulated match-play vs. the corresponding post 90-min time-point (299 ± 29 µâˆ™L-1; p < .01). The 120-min trial caused a 58% higher CK response at 72-hr (244 ± 25 µâˆ™L-1) vs. post 90-min comparisons (154 ± 29 µâˆ™L-1; p = .02). No interaction effects were detected for any other recovery variables. Creatine kinase and perceived muscle soreness remained elevated up to 72-hr in both trials (p < .01). Conclusions: These data indicate that 120 min of simulated soccer match-play delays the time-course of CK recovery up to 72-hr post-match. However, 120 min of simulated soccer has no additional impact on functional recovery and perceived muscle soreness vs. 90 min. Recovery should be investigated following 90- and 120-min of actual match-play.Trial registration The study was pre-registered on the Open Science Framework (DOI: 10.17605/OSF.IO/VGU6T Date: 10/06/2019).

The influence of fixture congestion on physical performance response to U23 soccer match-play.

This study sought to examine differences in measures of intense periods of physical performance during competitive match-play, between one-match (1 match weeks) and two-match microcycles (2 match week). 1, 3 and 5 min "peak" and mean averages for total distance (TD), high-speed running (HSR) and metabolic power (MP) were analysed for each 15 min period of match-play. Linear mixed models were employed to examine the differences in dependent variables for each method of measurement between the 1 and 2 game microcycles. No differences were reported for "peak" values for all epoch lengths, however, results revealed significantly reduced "average" values, during periods of fixture congestion, for 1, 3 and 5 min epochs for average TD, and 3 min epochs for average HSR towards the end of the match (75-90 min split). There was, however, a trend for the opposite response to occur in the 60-75-min period. The current data suggests that players potentially display altered pacing strategies during periods of fixture congestion, with these observed responses being dependent on sampling method and epoch length.

The Effects of Fixture Congestion on Injury in Professional Male Soccer: A Systematic Review.

BACKGROUND: Professional soccer teams are often required to compete with ≤ 4 days recovery between matches. Since congested schedules reduce recovery time between matches, players are possibly at an increased injury risk. To date, there are no published systematic reviews on the impact of match congestion on injuries during professional male soccer. OBJECTIVE: The aim of this systematic review was to assess the effects of fixture congestion on injuries during professional soccer. METHODS: Following pre-registration on the Open Science Framework ( https://osf.io/86m25/ ) and conforming with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, systematic searches of four electronic databases (PubMed, Scopus, SPORTDiscus, and Web of Science) were conducted by independent researchers from inception until February 2022. Articles were included if they were original articles written in English and contained relevant time-loss injury data (injury that results in unavailability for training and/or match-play) for male professional soccer players regarding periods of fixture congestion (a minimum of two matches with ≤ 4 days recovery). RESULTS: A total of eight articles were included in the review. Five studies identified that congested fixture schedules expose players to increased match injury incidence, although layoff duration was typically lower during congested periods. Two studies identified that training and overall injury incidence were higher during congested periods, with another study identifying a lower training injury incidence during congested periods. CONCLUSION: Injury risk is, overall, increased during fixture-congested periods; however, the layoff duration is typically shorter. The current findings have implications for practitioners regarding the management, periodisation, monitoring, and design of training and competition schedules.

The influence of angle-specific torque of the knee flexors and extensors on the angle-specific dynamic control ratio in professional female soccer players.

The purpose of this study was to assess whether dynamic torque ratios (DCR) from isokinetic strength assessments of eccentric knee flexors (eccKF) and concentric knee extensors (conKE) display differences when stratified into specific angle-specific DCR (DCRAST) groups. Fifty-two professional female soccer players (age 21.30 ± 4.44 years; height 166.56 ± 5.17 cm; mass 61.55 ± 5.73 kg) from the English Women's Super League completed strength assessments of both lower limbs on an isokinetic dynamometer at 60°âˆ™s-1. Angle-specific torque (AST) were used to calculate DCRAST to create sub-groups using clustering algorithms. The results identified for the dominant side that the Medium DCRAST group elicited significantly higher conKE AST when compared to Low and High DCRAST groups at increased knee extension (P ≤ 0.05). For the non-dominant side, the High DCRAST group had significantly higher and lower eccKF and conKE AST compared to the Low DCRAST group at increased knee extension (P ≤ 0.05). This study highlights that the inclusion of AST data may subsequently help practitioners to prescribe exercise that promotes strength increases at targeted joint angles. In turn, these approaches can be used to help reduce injury risk, identify rehabilitation responses and help inform return to play.

Recovery following the extra-time period of soccer: practitioner perspectives and applied practices.

Research has demonstrated that the extra-time (ET) period of soccer negatively impacts recovery. However, it is not known to what extent recovery practices are being adapted by practitioners following ET and where gaps exist between research and practice. Therefore, this study explored soccer practitioner perceptions of recovery practices following ET matches. A total of 72 practitioners from across different levels of soccer and several countries completed a bespoke online survey. Inductive content analysis of the responses identified five higher-order themes: 'conditioning', 'player monitoring', 'recovery practices', 'training', and 'future research directions'. Mixed responses were received in relation to whether practitioners condition players in preparation for ET, though 72% allowed players to return to training based on fatigue markers following this additional 30-min period. Sixty-three (88%) practitioners believed that ET delays the time-course of recovery, with 82% highlighting that practices should be adapted following ET compared with a typical 90-min match. Forty-nine practitioners (68%) reduce training loads and intensities for up to 48 hr post ET matches, though training mostly recommences as 'normal' at 72 hr. Sixty-three (88%) practitioners believed that more research should be conducted on recovery following ET, with 'tracking players physiological and physical responses', 'nutritional interventions to accelerate recovery' and 'changes in acute injury-risk' being the three areas of research that practitioners ranked as most important. These data suggest practitioners and coaches adjust recovery practices following ET matches compared to 90 min. Further research on the efficacy of recovery strategies following ET matches is required to inform applied practice.

The demands of the extra-time period of soccer: A systematic review.

OBJECTIVE: Soccer match-play is typically contested over 90 min; however, in some cup and tournament scenarios, when matches are tied, they proceed to an additional 30 min, which is termed "extra-time" (ET). This systematic review sought to appraise the literature available on 120-min of soccer-specific exercise, with a view to identifying practical recommendations and future research opportunities. METHODS: The review was conducted according to the PRISMA guidelines. Independent researchers performed a systematic search of PubMed, CINAHL, and PsycINFO in May 2019, with the following keywords entered in various combinations: "soccer", "football", "extra-time", "extra time", "extratime", "120 minutes", "120 min", "additional 30 minutes", and "additional 30 min". RESULTS: The search yielded an initial 73 articles. Following the screening process, 11 articles were accepted for analyses. Articles were subsequently organized into the following 5 categories: movement demands of ET, performance responses to ET, physiological and neuromuscular response during ET, nutritional interventions, and recovery and ET. The results highlighted that during competitive match-play, players cover 5%-12% less distance relative to match duration (i.e., meters per minute) during ET compared to the preceding 90 min. Reductions in technical performance (i.e., shot speed, number of passes and dribbles) were also observed during ET. Additionally, carbohydrate provision may attenuate and improve dribbling performance during ET. Moreover, objective and subjective measures of recovery may be further compromised following ET when compared to 90 min. CONCLUSION: Additional investigations are warranted to further substantiate these findings and identify interventions to improve performance during ET.

Lower-Limb Muscle Excitation, Peak Torque, and External Load Responses to a 120-Minute Treadmill-Based Soccer-Specific Simulation.

Purpose: The aim of this study was to investigate thigh musculature excitation and torque generation in response to soccer-specific exercise incorporating an extra-time (ET) period. Methods: Twelve semiprofessional soccer players performed 120-min treadmill-based soccer-specific exercise. Surface electromyography (EMG) signals for the rectus femoris (EMGRF) and biceps femoris (EMGBF) were measured as the mean response across a pre-determined 10-second sprint bout during each 15-min block of exercise. Peak eccentric torque of the knee flexors (eccKF) and concentric torque of the knee extensors (conKE) were recorded across angular velocities of 60, 180, and 270 deg∙s-1 immediately pre- and post-exercise. Tri-axial PlayerLoad™ (PL-T) was monitored throughout exercise and defined across vertical (PL-V), anterior-posterior (PL-AP), and medial-lateral (PL-ML) planes of motion. Results: A reduction in normalized EMGRF amplitude was evident at 105‒120 min, versus 0‒15 min (-12.5%; p = .037), 15‒30 min (-12.5%; p = .047), and 45‒60 min (-14%; p = .030). Peak torque of the eccKF was significantly reduced from pre- to post-exercise at 60 (-7.7%; p = .018), 180 (-10.5%; p = .042), and 270 deg∙s-1 (-7.5%; p = .034). A main effect for time was identified for PL-T (p < .010), PL-V (p = .033), and PL-AP (p < .010). Conclusions: These findings suggest that muscle excitation of the rectus femoris is reduced during ET, accompanied with a deficit in the torque generation of the knee flexors following 120 min of soccer-specific activity. Practitioners should adequately condition players for the additional ET period by incorporating exercises into training schedules that develop fatigue-resistant eccentric hamstring strength to minimize injury risk.

The prevalence of pre-conditioning and recovery strategies in senior elite and non-elite amateur boxing.

OBJECTIVES: A variety of acute strategies around competition are used to prepare and promote physical and mental restoration in athletes. However, to date, no research exists on the prevalence of such methods in amateur boxing. Therefore, this study aimed to 1) examine the prevalence of pre-conditioning and recovery strategies in amateur boxing; 2) ascertain whether this was discriminated against at competitor level. METHODS: This study surveyed 101 senior amateur boxers (Senior Elite SEB n = 59; Senior Development SDB n = 42), on their application and perceptions of pre-conditioning and recovery strategies. RESULTS: The reported findings determined a significantly greater number of SEB performed resistance priming activity up to 48 hours prior to competition (11, 19% vs 2, 5%; P = 0.040), and post-activation performance enhancement (PAPE) activity in the pre-competition warm-up (18, 31% vs 1, 2%; P < 0.001), compared to SDB. Likewise, SEB reported they were also significantly more likely to utilize massage (SEB 35, 59%, SDB 11, 29%, P = 0.001) and cold-water immersion (CWI) (SEB 28, 47%, SDB 10, 29%, P = 0.016) as recovery modes, compared to their SDB counterparts. CONCLUSIONS: This study was the first to provide data on the use of PAPE, priming and recovery methods around amateur boxing bouts. Increased access to multi-disciplinary staff could be expected in SEB, possibly explaining the greater prevalence of evidence-based methods around competition. Once athlete responsiveness to PAPEand longer-term priming methods are initially assessed, these strategies could be implemented to improve punch-specific performance, though more research is needed on their efficacy. Likewise, boxers could utilize evidence-based recovery modes where possible, with increased importance during repeat-bout scenarios, such as domestic tournaments. Coaches and practitioners may use this data to implement pre-conditioning and recovery strategies, to optimize performance and reduce the risk of injury of amateur boxers.

Upper-Body Post-activation Performance Enhancement for Athletic Performance: A Systematic Review with Meta-analysis and Recommendations for Future Research.

BACKGROUND: Research on post-activation performance enhancement (PAPE) is dominated by lower-body conditioning activities/performance test complexes. Despite the contribution of the upper body to many sporting actions, no review on upper-body PAPE currently exists. OBJECTIVES: The aim of this systematic review with meta-analysis was to provide a synthesis of the available research on the inclusion of upper-body PAPE conditioning activities to improve athletic performance. METHODS: A review of the literature was conducted according to the Preferred Reporting Items for Systematic Review and Meta-analyses guidelines, including a literature search of EBSCOhost, SPORTDiscus, PubMed and Google Scholar databases. A total of 127 studies were identified through database searches, and were assessed against the following criteria: (1) randomised controlled trial or pre-and-post study design; (2) studies explored the effects of prior voluntary muscle activity, and not electrically induced contractions, (3) evidence, or lack thereof, of PAPE was quantified by the monitoring of individual performance to commonly applied physical tests or sport-specific tasks; (4) conditioning activities and performance tests were primarily upper-body; (5) detailed description of a standardised warm-up; and (6) full-text versions of studies could be accessed in English language peer-reviewed journals. Studies were quality assessed for methodological quality via the PEDro scale and ranked accordingly. RESULTS: Thirty-one studies met the inclusion criteria. Studies were classified into different conditioning activity modes: bench press variations, sport-specific (modified implement throws, swing-specific, cable pulley, elastic resistance, combination) and bodyweight activity. Acute performance enhancement in several movement-specific combinations was found. A meta-analysis revealed that bench press at ≥ 80% one repetition maximum significantly (p = 0.03; ES = 0.31) improves subsequent power output in the ballistic bench throw at 30-40% one repetition maximum, following 8-12 min recovery. Additionally, sport-specific overweight implement throws improved subsequent throwing distance at competition weight by ~ 1.7-8.5%; ES = 0.14-0.33, following 3 min recovery. Sport-specific lighter weighted bat swings and swing-specific isometrics resulted in improved subsequent competition weight bat swing velocities, ranging from ~ 1.3-4.9%; ES = 0.16-0.57. CONCLUSIONS: This review presents several upper-body movement-specific conditioning activities that could be considered by coaches and practitioners as part of complex or contrast training, or used in pre-competition warm-ups to acutely enhance performance.

The association between competitor level and the physical preparation practices of amateur boxers.

Physical training, testing, and monitoring are three key constitutes of athlete physical performance; however, there is a currently a lack of information on the prevalence of such methods in amateur boxing. This study aimed to explore the physical preparation practices of senior elite (SEB) and senior development (SDB) amateur boxers, and to determine whether these practices were discriminated by competitor level. One hundred and one amateur boxers (SEB n = 59, SDB n = 42) were surveyed on their understanding, perceptions and application of physical training, monitoring, and testing practices. SEB were associated with strength/power training (SEB 78%, SDB 50%, P = 0.005), monitor of training intensities (SEB 68%, SDB 40%, P = 0.006), and performing regular fitness testing (SEB 76%, SDB 50%, P = 0.006), compared to SDB. Likewise, SEB were twice as likely (56%) to have their physical preparation managed by a strength and conditioning (S&C) coach or sport scientist, compared to SDB (26%; P = 0.005). For the first time, these data demonstrate the extent to which competitor level is associated with preparatory practices in amateur boxing. Cost was identified as the main barrier in implementing several forms of scientific support in SDB. These data serve as a framework to enhance preparatory practices across different competitor levels in amateur boxing. This might include boxer and coach education on the benefits to a more scientific approach, and the use of cost-effective methods to develop, monitor and assess amateur boxers physical performance. This may be of particular importance where boxers are not funded, such as the SDB in the current study. However, this work may also be used to emphasise the importance of strength/power training, physical fitness testing and monitoring at the elite level of amateur boxing.

The Effect of Fixture Congestion on Performance During Professional Male Soccer Match-Play: A Systematic Critical Review with Meta-Analysis.

BACKGROUND: Fixture congestion (defined as a minimum of two successive bouts of match-play, with an inter-match recovery period of < 96 h) is a frequent and contemporary issue in professional soccer due to increased commercialisation of the sport and a rise in the number of domestic and international cup competitions. To date, there is no published systematic review or meta-analysis on the impact of fixture congestion on performance during soccer match play. OBJECTIVE: We sought to conduct a systematic review and meta-analysis of the literature related to the effects of fixture congestion on physical, technical, and tactical performance in professional soccer match-play. METHODS: Adhering to PRISMA guidelines and following pre-registration with the Open Science Framework ( https://osf.io/fqbuj ), a comprehensive and systematic search of three research databases was conducted to identify articles related to soccer fixture congestion. For inclusion in the systematic review and meta-analysis, studies had to include male professional soccer players, a congestion period that contained two matches ≤ 96 h, and have outcome measures related to physical, technical or tactical performance. Exclusion criteria comprised non-male and/or youth players, data that only assessed impact of congestion on injury, used simulated protocols, or were grey literature, such as theses or dissertations. RESULTS: Out of sixteen articles included in the systematic review, only five were eligible for the meta-analysis, and the only variable that was measured consistently across studies was total distance covered. Fixture congestion had no impact on total distance covered [p = 0.134; pooled standardized mean difference; Hedge's G = 0.12 (- 0.04, 0.28)]. Between-study variance, heterogeneity, and inconsistency across studies were moderate [Cochrane's Q = 6.7, p = 0.150, I2 = 40.7% (CI 0.00, 93.34)]. Data from articles included in the systematic review suggest fixture congestion has equivocal effects on physical performance, with variation between studies and low quality of research design in some instances. Tactical performance may be negatively impacted by fixture congestion; however, only one article was identified that measured this element. Technical performance is unchanged during fixture congestion; however, again, research design and the sensitivity and relevance of methods and variables require improvement. CONCLUSION: Total distance covered is not impacted by fixture congestion. However, some studies observed a negative effect of fixture congestion on variables such as low- and moderate-intensity distance covered, perhaps suggesting that players employ pacing strategies to maintain high-intensity actions. There is a lack of data on changes in tactical performance during fixture congestion. With ever increasing numbers of competitive matches scheduled, more research needs to be conducted using consistent measures of performance (e.g., movement thresholds) with an integration of physical, technical and tactical aspects.

The cumulative and residual changes in eccentric knee flexor strength indices following soccer-specific treadmill running: Novel considerations of angle specific torque.

With potential implications for recovery and conditioning practices, the aim of this study was to assess the cumulative and residual response of angle specific eccentric knee flexor (eccKF) strength indices following soccer-specific activity. Thirteen semi-professional soccer players were therefore required to complete a 90-minute soccer-specific treadmill running. with eccKF isokinetic strength assessments completed pre-trial, immediately post-trial, and 48 hours post-trial. The strength assessments comprised the completion of 5 repetitions at angular velocities of 60 and 300 deg·s-1. Isokinetic data was analysed for measures of peak torque (PT), angle of peak torque (APT), functional range (FR), and angle specific torque (AST). Significant post-trial impairments were observed for measures of slow velocity PT60 (6.6%) and AST300 (12.5%). Further significant differences were observed 48 hours post-trial for PT300 (10.7%) and PT60 (12.8%) PT, APT60 (~15°), and AST300 (>13.6%). These data have implications for post exercise recovery monitoring and the prescription of recovery modalities and conditioning practices in the 2 days following match-play. The AST and APT responses highlight the importance of analysis of the entire strength-angle curve and at a range of angular velocities.

Biomechanical and Physiological Responses to 120 Min. of Soccer-Specific Exercise.

Purpose: The purpose of the study is to investigate biomechanical and physiological responses to soccer-specific exercise incorporating an extra-time period (ET) and assess the test-retest reliability of these responses. Methods: Twelve soccer players performed 120 min of soccer-specific exercise. Tri-axial (PLTotal) and uni-axial PlayerLoad™ in the vertical (PLV), anterior-posterior (PLA-P), and medial-lateral (PLM-L) planes were monitored using a portable accelerometer. Likewise, respiratory exchange ratio (RER) was recorded throughout exercise. At the end of each 15-min period, players provided differential ratings of perceived exertion for legs (RPE-L), breathlessness (RPE-B) and overall (RPE-O), and capillary samples were taken to measure blood lactate (BLa) concentrations. The soccer-specific exercise was completed twice within 7 days to assess reliability. Results: A main effect for time was identified for PLTotal (p = 0.045), PLV (p = 0.002), PLA-P (p = 0.011), RER (p = 0.001), RPE-L (p = 0.001), RPE-O (p = 0.003), and CMJ (p = 0.020). A significant increase in PLTotal (234 ± 34 au) and decrease in RER (0.87 ± 0.03) was evident during 105-120 versus 0-15 min (215 ± 25 au; p = 0.002 and 0.92 ± 0.02; p = 0.001). Coefficients of variations were <10% and Pearson's correlation coefficient demonstrated moderate-to-very strong (0.33-0.99) reliability for all PL variables, RPE-B, BLa, and RER. Conclusions: These results suggest that mechanical efficiency is compromised and an increased rate of lipolysis is observed as a function of exercise duration, particularly during ET. These data have implications for practitioners interested in fatigue-induced changes during ET.

The cumulative and residual fatigue response associated with soccer-specific activity performed on different playing surfaces.

This study aimed to assess the effect of playing surface (Natural [NT] and Artificial [AT] Turf) on the fatigue response to a soccer-specific exercise protocol (SSEP). Eighteen male soccer players completed the SSEP on NT and AT with pre-, post-, and 48 h post-assessments of eccentric knee flexor (eccKF) and concentric knee extensor peak torque (PT), peak countermovement (CMJ) and squat jump (SJ) height, and Nordic hamstring break angle. No significant main effects for surface or any surface and time interactions were observed for any of the outcome measures, except for eccKF PT recorded at 3.14 rad·s-1, which was significantly lower 48 h post-trial in the AT condition (AT = 146.3 ± 20.4 Nm; NT = 158.8 ± 24.7 Nm). Main effects for time were observed between pre- and post-trial measures for eccKF PT at all angular velocities, Nordic break angle, CMJ and SJ height. Nordic break angle, and both CMJ and SJ height were significantly impaired 48 h post-trial when compared to pre-trial. The findings of the current study suggest surface dependent changes in eccKF PT which may have implications for recovery and subsequent performance after competition on AT.

The effectiveness of a practical half-time re-warm-up strategy on performance and the physical response to soccer-specific activity.

The aim of this study was to assess the influence of a half-time (HT) re-warm up (RWU) strategy on measures of performance and the physical and perceptual response to soccer-specific activity. Ten male soccer players completed a control (CON) and RWU trial, in which participants completed 60 min (4 x 15-min periods with a 15-min HT interspersing the third and fourth periods) of a soccer-specific exercise protocol. The CON trial comprised a passive 15-min HT, whilst the RWU trial comprised a passive 12-min period, followed by a 3-min RWU. The RWU elicited an improvement in 20 m sprint times (d= 0.6; CON: 3.42 ± 0.20 s; RWU: 3.32 ± 0.12 s), and both squat (d= 0.6; CON: 26.96 ± 5.00 cm; RWU: 30.17 ± 5.13 cm) and countermovement jump height (d= 0.7; CON: 28.15 ± 4.72 cm; RWU: 31.53 ± 5.43 cm) following the RWU and during the initial stages of the second half. No significant changes were identified for 5 m or 10 m sprint performance, perceived muscle soreness, or PlayerLoadTM. Ratings of perceived exertion were however higher (~2 a.u) following the RWU. These data support the use of a HT RWU intervention to elicit acute changes in performance.

Isokinetic strength differences between elite senior and youth female soccer players identifies training requirements.

OBJECTIVES: To compare traditional and angle-specific isokinetic strength of eccentric knee flexors and concentric knee extensors in female senior professional and youth soccer players. DESIGN: Cross-sectional study design. SETTING: University's Laboratory. PARTICIPANTS: A total of 34 players (17 seniors [age 25.31 ±â€¯4.51 years; height 167.89 ±â€¯7.04 cm; mass 63.12 ±â€¯7.79 kg] and 17 youths [16.91 ±â€¯1.16 years; height 165.92 ±â€¯4.42 cm; mass 60.07 ±â€¯4.48 kg]) from the Women's Super League 1 completed strength assessments at 180, 270 and 60°âˆ™s-1. MAIN OUTCOME MEASURES: Peak torque (PT), dynamic control ratio (DCR), angle of peak torque (APT), functional range (FR), angle-specific torque (AST) and angle-specific DCR (DCRAST) were compared between age groups. RESULTS: The PT (P = 0.016) AST (P = 0.041) were significantly higher in seniors compared to youths; however APT (P = 0.141), DCR (P = 0.524) FR (P = 0.821) and DCRAST (P = 0.053) were not significant between playing age. CONCLUSION: The use of absolute and angle-specific strength measures were able to distinguish between female playing ages, whereas DCR and DCRAST was unable to identify differences. The PT and AST metrics may be the most useful metrics to help identify and inform training needs, particularly in youths.

Acute adaptations and subsequent preservation of strength and speed measures following a Nordic hamstring curl intervention: a randomised controlled trial.

This randomised controlled trial investigated changes in eccentric hamstring strength, 10m sprint speed, and change-of-direction (COD) performance immediately post Nordic hamstring curl (NHC) intervention and following a 3-week detraining period. Fourteen male team sports athletes were randomised to a do-as-usual control group (CG; n = 7) or to a NHC intervention group (NHC; n = 7). Isokinetic dynamometry at 180°/s evaluated eccentric hamstring strength immediately post-intervention as the primary outcome measure. Secondary outcomes included 10 m sprint time and COD. Each outcome was measured, pre, immediately post-intervention and following a 3-week detraining period. Immediately post-intervention significant group differences were observed in the NHC group for eccentric hamstring strength (31.81 Nm-1 vs. 6.44 Nm-1, P = 0.001), COD (-0.12 s vs. 0.20 s; P = 0.003) and sprint (- 0.06 s vs. 0.05 s; P = 0.024) performance. Performance improvements were maintained following a detraining period for COD (-0.11 s vs. 0.20 s; P = 0.014) and sprint (-0.05 s vs. 0.03 s, P = 0.031) but not eccentric hamstring strength (15.67 Nm-1 vs. 6.44 Nm-1, P = 0.145) These findings have important implications for training programmes designed to reduce hamstring injury incidence, whilst enhancing physical qualities critical to sport.