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Davies, TB, Halaki, M, Orr, R, Mitchell, L, Helms, ER, Clarke, J, and Hackett, DA. Effect of set structure on upper-body muscular hypertrophy and performance in recreationally trained men and women. J Strength Cond Res 36(8): 2176–2185, 2022—This study explored the effect of volume-equated traditional-set and cluster-set structures on muscular hypertrophy and performance after high-load resistance training manipulating the bench press exercise. Twenty-one recreationally trained subjects (12 men and 9 women) performed a 3-week familiarization phase and were then randomized into one of two 8-week upper-body and lower-body split programs occurring over 3 and then progressing to 4 sessions per week. Subjects performed 4 sets of 5 repetitions at 85% one repetition maximum (1RM) using a traditional-set structure (TRAD, n = 10), which involved 5 minutes of interset rest only, or a cluster-set structure, which included 30-second inter-repetition rest and 3 minutes of interset rest (CLUS, n = 11). A 1RM bench press, repetitions to failure at 70% 1RM, regional muscle thickness, and dual-energy x-ray absorptiometry were used to estimate changes in muscular strength, local muscular endurance, regional muscular hypertrophy, and body composition, respectively. Velocity loss was assessed using a linear position transducer at the intervention midpoint. TRAD demonstrated a significantly greater velocity loss magnitude (g = 1.50) and muscle thickness of the proximal pectoralis major (g = −0.34) compared with CLUS. There were no significant differences between groups for the remaining outcomes, although a small effect size favoring TRAD was observed for the middle region of the pectoralis major (g = −0.25). It seems that the greater velocity losses during sets observed in traditional-set compared with cluster-set structures may promote superior muscular hypertrophy within specific regions of the pectoralis major in recreationally trained subjects. [ABSTRACT FROM AUTHOR]

Purpose: To investigate activity profiles of Australian rugby league players during match play by competition, position, and match outcome in the New South Wales (NSW) second-tier competitions. Methods: Eighteen NSW Cup (NSWC) and 22 National Youth Competition (NYC) players, participating in this prospective cohort study, were categorized into 3 positional groups: forwards, adjustables, and outside backs. Global positioning system devices were used to examine activity profiles (distance and relative distance covered in walking, jogging, moderate, high, very high, and sprinting speed zones and quantification of high-speed movement) during match play in 21 NSWC and 22 NYC matches (N = 339 files). Results: NSWC players performed more sprints (36.5 ± 9.3 vs 28.4 ± 9.2) and greater relative distance in moderate speed zones (18.4 ± 3.2 vs 15.8 ± 3.1 m/min) than NYC. NSWC outside backs covered greater relative distance in jogging (29.4 ± 2.9 vs 24.8 ± 2.7 m/min) and moderate speed zones (17.0 ± 2.6 vs 12.8 ± 2.8 m/min) than their NYC counterparts. Adjustables performed more sprints (39.4 ± 10.1 vs 27.0 ± 9.2), high-intensity accelerations (3.7 ± 1.4 vs 1.9 ± 1.4), and relative distance (84.8 ± 4.3 vs 88.6 ± 4.8 m/min) than forwards and greater relative distance (81.5 ± 3.8 m/min) and sprints (31.0 ± 8.0) than outside backs. Adjustables recorded greater relative distance (19.8 m/min) in moderate speed zones than forwards (16.7 ± 3.1 m/min) and outside backs (14.9 ± 2.7 m/min). Adjustables covered ~685 m more than outside backs during a win. Conclusions: This is the first study to document the activity profiles of the NSW second-tier rugby league competition. The findings underscore the elevated match demands of adjustables and indicate higher intensity of play in NSWC than NYC that may more closely resemble the demands of National Rugby League match play. [ABSTRACT FROM AUTHOR]

Background/aims: High-intensity power training has been shown to be effective in improving muscular capabilities, functional performance and health-related quality of life in populations with physical impairments. However, the effectiveness of high-intensity power training in people with Charcot–Marie–Tooth disease remains uncertain. This case series investigated the effects of high-intensity power training on muscle performance, function and health-related quality of life in middle-aged women with Charcot-Marie-Tooth disease. Methods: Four women (age 51–58 years) with Charcot–Marie–Tooth disease type 1A participated in 8 weeks of supervised high-intensity power training. Results: All participants improved strength of the right hip abductors (46.7–109.7%) and left hip abductors (27.3–128.6%), maximal gait speed (2.3–9.1%), static balance (0.7–4.9%), tandem walk (−3.3 to −58.5%), and mental component scores on the Short Form 36 Health Status Survey (0.8–27.6%). Adherence to high-intensity power training was 100% and only one minor adverse event related to the intervention was reported. Conclusions: Although promising, larger controlled studies are indicated to confirm the safety and efficacy of high-intensity progressive resistance and power training in this cohort. [ABSTRACT FROM AUTHOR]

This study investigated the effects of high-load cluster- or traditional-set structures using the bench press on velocity and power. Twenty-one resistance-trained individuals (male = 12, female = 9) performed a 3-week familiarization block followed by randomization into 1 of 2 upper- and lower-body split training routines performed for 8 weeks. The bench press was the only exercise manipulated with subjects using either cluster-set (CLUS, n = 11) or traditional-set (TRAD, n 5 10) structures during training sessions. Subjects performed 4 sets of 5 repetitions at 85% 1 repetition maximum (1RM) with CLUS having a 30-second inter-repetition, and 3-minute interset rest while TRAD had a 5-minute interset rest. A load-velocity profile of relative loads derived from a 1 RM test was used to assess velocity and power (absolute and relative to body mass) on the bench press. Significant improvements over time were found across various loads ranging from 45 to 75% 1RM for absolute and relative peak power (p 5 0.006-0.041), and mean power (p = 0.001-0.032). Significant decreases over time were found at 55% 1RM and 65% 1 RM for peak velocity (p 5 0.027 and p 5 0.012, respectively) and mean velocity (p 5 0.047 and p 5 0.022, respectively). There were no significant group or group by time interactions found for all outcomes. Within the context of high-load resistance training, set structure seems to be of less importance for changes in bench press velocity and power provided there is an intention to lift with maximal concentric velocity. [ABSTRACT FROM AUTHOR]

Background: The effect of resistance training (RT) on adaptations in muscular strength and hypertrophy has never been examined in an exclusively female synthesis of the literature. Objective: The objectives of this study were threefold: (1) to systematically review the literature on female adaptations to RT, characterising the effect in terms of muscular strength and hypertrophy; (2) to distinguish the individual effects of intervention duration, frequency, and intensity on these adaptations via sub-analysis; (3) to draw evidence-based conclusions regarding training expectations in female populations. Methods: Three electronic databases were searched using terms related to RT combined with females or women. Random-effects meta-analyses were undertaken to estimate the effect of RT on muscular strength and hypertrophy in females. Possible predictors that may have influenced training-related effects (e.g., training intensity and volume) were explored using univariate analyses. Results: The systematic search identified 14,067 articles of which a total of 24 studies met the inclusion criteria and were eligible. Upper body strength was assessed in 15 studies, lower body strength in 19 studies, and muscular hypertrophy in 15 studies. Study duration lasted between 4 weeks and 12 months. Large-effect sizes were found for upper body strength (Hedges' g = 1.70; p < 0.001) and lower body strength (Hedges' g = 1.40; p < 0.001). Following use of the Trim and Fill method (due to presence of publication bias), a large effect still remained for upper body strength (Hedges' g = 1.07), although a medium effect was found for lower body strength (Hedges' g = 0.52). A medium effect was found for muscular hypertrophy (g = 0.52, p = 0.002). Sub-analyses revealed that the moderating variables "training frequency" and "training volume" significantly influenced lower body muscular strength (p < 0.001). "Training frequency" and "sets per exercise" moderated the RT effects on upper body strength (p < 0.01). No moderating variables were found to significantly influence muscular hypertrophy. A trend for a moderating effect on upper body strength was found for "age of participants" (p = 0.08), whereby younger participants experienced a greater effect. A moderating effect was also observed where supervised training had a larger influence on the adaptation of lower body strength (p = 0.05) compared with unsupervised training. Methodological quality for the studies included in the review was found to be moderate. Conclusions: RT elicits large improvements in muscular strength and hypertrophy in healthy adult females. Training volume and frequency appear to be important variables that influence muscular strength. [ABSTRACT FROM AUTHOR]

The purpose of this study was to describe and compare the metabolic demands of rugby league for interchange and full-match players in relation to positional groups. Eighteen elite rugby league players were recruited. A time-motion model was used to estimate the energy expenditure and metabolic demands of rugby league match-play using Global Positioning System (GPS) technology. This approach uses players' GPS velocity-time curves to examine running velocity. Players were categorized into positional groups (outside backs, adjustables, wide-running, and hit-up forwards) and then further categorized into full-match or interchange players. Compared with their full-match counterparts, interchange wide-running forwards expended greater energy (43.1 ± 6.1 vs. 28.6 ± 7.5 kJ⋅kg-1, p ≤ 0.001, effect size [ES] = -2.38) and produced a higher anaerobic index (p = 0.016, ES = 0.56) and mean power (7.4%, p = 0.003, ES = 0.66) per match. Full-match adjustables expended 94.8% more energy (p ≤ 0.001, ES = -2.3) and performed more moderate accelerations (10.1%, p = 0.014, ES = -0.57) and decelerations (7.6%, p = 0.017, ES = -0.8), than their interchange counterparts. Outside backs did not interchange and hit-up forwards rarely (n = 2) played an entire match. Differing metabolic demands were identified for interchange and full-match players across positional groups, suggesting position-specific conditioning drills are required to model the energetic demands of match-play. [ABSTRACT FROM AUTHOR]

Introduction: Studies of cerebral haemodynamics have shown changes with increased exercise intensity, but the patterns have been highly variable and reliable associations with cognitive performance have not been identified. The aim of this study was to examine whether exercise-induced changes in oxygenated haemoglobin (O2Hb) led to changes in concomitant cognitive performance.Methods: This study examined cardiorespiratory and cerebral haemodynamics during multi-stage exercise from rest to exhaustion, with (Ex + C) and without (Ex) concurrent cognitive performance (Go/No-go task).Results: The presence of the cognitive task affected both cardiorespiratory and cerebral haemodynamics. The patterns in the cerebral haemodynamics during Ex and Ex + C diverged above the respiratory compensation threshold (RCT), but differences were significant only at 100% [Formula: see text], displaying increased deoxygenated haemoglobin (HHb), decreased difference between oxygenated and deoxygenated haemoglobin (HbDiff), and decreased cerebral oxygenation (COx) during Ex + C. More complex haemodynamic trends against intensity during Ex + C suggested that the presence of a cognitive task increases cerebral metabolic demand at high exercise intensities. The levels of O2Hb, HHb, HbDiff and total haemoglobin increased most steeply at intensities around the RCT during both Ex and Ex + C, but these changes were not accompanied by improved cognitive performance.Conclusion: The primary hypothesis, that cognitive performance would match changes in O2Hb, was not supported. Small variations in reaction time and response accuracy across exercise intensities were not significant, suggesting that cognitive performance is unaffected by intense short-duration exercise. Our results add further evidence that exercise-induced changes in cerebral haemodynamics do not affect cognitive performance. [ABSTRACT FROM AUTHOR]

Background: The use of global positioning system (GPS) devices with the inclusion of microsenor technology in rugby league enables measurement of player activity profiles to understand the demands of match-play and optimise on-field performance. Objective: The aim of this review was to systematically review the use of GPS and microsensor technology to quantify player activity profiles in match-play, and conduct a meta-analysis of relevant movement variables in order to present the contemporary and emerging themes within rugby league. Methods: A systematic search of electronic databases (MEDLINE, SPORTDiscus, CINAHL, Web of Science, Scopus, ScienceDirect, EMBASE, and Google Scholar) from the earliest record to February 2015 was conducted. Permutations of key words included GPS, microtechnology, activity profiles, match demands (movement or physical demands), and rugby league. A meta-analysis was conducted to provide a pooled mean and confidence intervals on comparable data from at least three studies. Results: Twenty-seven studies met the eligibility criteria and included 1270 male participants. The studies reported on GPS use in elite competition ( n = 16) with limited representation of other competition standards: sub-elite ( n = 6), amateur ( n = 1) and junior ( n = 3). All studies reported on movement variables (distance, relative distance, speed and accelerations), with studies analysing movement at high speed ( n = 18, 66.7 %), evaluating collision or impact variables ( n = 15, 55.6 %) and determining the metabolic energy ( n = 2, 7.4 %) associated with rugby league match-play. Activity profiles of varying positions, positional groups and levels of rugby league competition were described. Meta-analysis indicated that the total distance covered by backs and adjustables were both greater than forward positions, but adjustables covered greater relative distance than forwards and backs. Speed zones were typically categorised into six speed zones ranging from 0 to 36 km·h, or into low- and high-intensity movement. Vast inconsistencies were apparent across studies in categorising movement at high speed, posing difficulties for comparison. Meta-analysis indicated that, although the number of repeated high-intensity effort (RHIE) bouts in elite players were similar to sub-elite (and both greater than juniors), the number of efforts per RHIE were significantly greater in elite than sub-elite players. Differential pacing strategies were adopted according to player selection (whole-match vs. interchange), time period within match-play and match outcome, in order to maintain high-intensity performance or to challenge for a win. Sizeable inconsistencies were also identified in the definitions of reported collisions (classified as mild, moderate and heavy) and impacts (six zone categories provided by manufacturer), making comparisons across studies difficult. Collision profiles were different between competition standard and position where elite players and forwards sustained more moderate- and high-intensity collisions than sub-elite players and backs, respectively. The recent inclusion of GPS-derived metabolic indices to activity profiles has also accentuated the distinctive workloads of positional groups during match-play where adjustables demonstrate the highest energy expenditure and metabolic power. Conclusions: This review and the results of the meta-analysis have demonstrated that positional groups have varied kinematic and metabolic demands. During match play, forwards sustain the greatest number of collisions and RHIE bouts, outside backs participate in more high-speed running and cover the greatest distance, and adjustables work at high intensity covering the greatest relative distance with the highest metabolic cost. Therefore, specific training for each positional group should address their match requirements. In addition, sub-elite players exhibit lower intensity of play compared with elite players, as indicated by lower relative distance and less number of efforts per RHIE bout despite similarities in total distance covered and number of RHIE bouts. To prepare them for elite-level play, their training should incorporate higher intensity drills in which greater relative distance and number of efforts per RHIE bout are performed. Furthermore, the lack of consistency in the definition of speed zones, high-intensity movement, collisions and impacts, underscores the difficulties encountered in meaningful comparisons of player activity profiles between studies. Consensus of these definitions would facilitate direct comparisons within rugby league. [ABSTRACT FROM AUTHOR]

Purpose: This study investigated whether short-term heart rate variability (HRV) can be used to differentiate between the immediate recovery periods following three different intensities of preceding exercise.Methods: 12 males cycled for 8 min at three intensities: LOW (40-45 %), MOD (75-80 %) and HIGH (90-95 %) of heart rate (HR) reserve. HRV was assessed during exercise and throughout 10-min seated recovery.Results: 1-min HR recovery was reduced following greater exercise intensities when expressed as R-R interval (RRI, ms) (p < 0.001), but not b min(-1) (p = 0.217). During exercise, the natural logarithm of root mean square of successive differences (Ln-RMSSD) was higher during LOW (1.66 ± 0.47 ms) relative to MOD (1.14 ± 0.32 ms) and HIGH (1.30 ± 0.25 ms) (p ≤ 0.037). Similar results were observed for high-frequency spectra (Ln-HF-LOW: 2.9 ± 1.0; MOD: 1.6 ± 0.6; HIGH: 1.6 ± 0.3 ms(2), p < 0.001). By 1-min recovery, higher preceding exercise intensities resulted in lower HRV amongst all three intensities for Ln-RMSSD (LOW: 3.45 ± 0.58; MOD: 2.34 ± 0.81; HIGH: 1.66 ± 0.78 ms, p < 0.001) and Ln-HF (LOW: 6.0 ± 1.0; MOD: 4.3 ± 1.4; HIGH: 2.8 ± 1.4 ms(2), p < 0.001). Similarly, by 1-min recovery 'HR-corrected' HRV (Ln-RMSSD: RRI × 10(3)) was different amongst all three intensities (LOW: 3.64 ± 0.49; MOD: 2.90 ± 0.65; HIGH: 2.40 ± 0.67, p < 0.001). These differences were maintained throughout 10-min recovery (p ≤ 0.027).Conclusion: Preceding exercise intensity has a graded effect on recovery HRV measures reflecting cardiac vagal activity, even after correcting for the underlying HR. The immediate recovery following exercise is a potentially useful period to investigate autonomic activity, as multiple levels of autonomic activity can be clearly differentiated between using HRV. When investigating post-exercise HRV it is critical to account for the relative exercise intensity. [ABSTRACT FROM AUTHOR]

Background: It remains unclear whether repetitions leading to failure (failure training) or not leading to failure (non-failure training) lead to superior muscular strength gains during resistance exercise. Failure training may provide the stimulus needed to enhance muscular strength development. However, it is argued that non-failure training leads to similar increases in muscular strength without the need for high levels of discomfort and physical effort, which are associated with failure training. Objective: We conducted a systematic review and meta-analysis to examine the effect of failure versus non-failure training on muscular strength. Methods: Five electronic databases were searched using terms related to failure and non-failure training. Studies were deemed eligible for inclusion if they met the following criteria: (1) randomised and non-randomised studies; (2) resistance training intervention where repetitions were performed to failure; (3) a non-failure comparison group; (4) resistance training interventions with a total of ≥3 exercise sessions; and (5) muscular strength assessment pre- and post-training. Random-effects meta-analyses were performed to pool the results of the included studies and generate a weighted mean effect size (ES). Results: Eight studies were included in the meta-analysis (combined studies). Training volume was controlled in four studies (volume controlled), while the remaining four studies did not control for training volume (volume uncontrolled). Non-failure training resulted in a 0.6-1.3 % greater strength increase than failure training. A small pooled effect favouring non-failure training was found (ES = 0.34; p = 0.02). Significant small pooled effects on muscular strength were also found for non-failure versus failure training with compound exercises (ES = 0.37-0.38; p = 0.03) and trained participants (ES = 0.37; p = 0.049). A slightly larger pooled effect favouring non-failure training was observed when volume-uncontrolled studies were included (ES = 0.41; p = 0.047). No significant effect was found for the volume-controlled studies, although there was a trend favouring non-failure training. The methodological quality of the included studies in the review was found to be moderate. Exercise compliance was high for the studies where this was reported ( n = 5), although limited information on adverse events was provided. Conclusion: Overall, the results suggest that despite statistically significant effects on muscular strength being found for non-failure compared with failure training, the small percentage of improvement shown for non-failure training is unlikely to be meaningful. Therefore, it appears that similar increases in muscular strength can be achieved with failure and non-failure training. Furthermore, it seems unnecessary to perform failure training to maximise muscular strength; however, if incorporated into a programme, training to failure should be performed sparingly to limit the risks of injuries and overtraining. [ABSTRACT FROM AUTHOR]

A correction to the article "Effect of Training Leading to Repetition Failure on Muscular Strength: A Systematic Review and Meta-Analysis" that was published online in February 2016 is presented.

Purpose This systematic review was conducted to identify the impact of upper body warm-up on performance and injury prevention outcomes. Methods Web of Science, MEDLINE, SPORTDiscus, PsycINFO and Cochrane databases were searched using terms related to upper extremity warm-up. Inclusion criteria were English language randomised controlled trials from peer-reviewed journals in which investigation of upper body warm-up on performance and injury prevention outcomes was a primary aim. Included studies were assessed for methodological quality using the PEDro scale. A wide variety of warm-up modes and outcomes precluded meta-analysis except for one group of studies. The majority of warm-ups were assessed as having 'positive', 'neutral', 'negative' or 'specific' effects on outcomes. Results Thirty-one studies met the inclusion criteria with 21 rated as having 'good' methodological quality. The studies investigated a total of 25 warm-up modes and 43 outcome factors that could be grouped into eight mode and performance outcome categories. No studies of upper body warm-up effects on injury prevention were discovered. Conclusions Strong research-based evidence was found for the following: high-load dynamic warm-ups enhance power and strength performance; warm-up swings with a standard weight baseball bat are most effective for enhancing bat speed; short-duration static stretching warm-up has no effect on power outcomes; and passive heating/cooling is a largely ineffective warm-up mode. A clear knowledge gap in upper body warm-up literature is the lack of investigation of injury prevention outcomes. [ABSTRACT FROM AUTHOR]