Operation early-bird: Investigating altered light exposure in military barracks on sleep and performance-a placebo-controlled study.

The manipulation of light exposure in the evening has been shown to modulate sleep, and may be beneficial in a military setting where sleep is reported to be problematic. This study investigated the efficacy of low-temperature lighting on objective sleep measures and physical performance in military trainees. Sixty-four officer-trainees (52 male/12 female, mean ± SD age: 25 ± 5 years) wore wrist-actigraphs for 6 weeks during military training to quantify sleep metrics. Trainee 2.4-km run time and upper-body muscular-endurance were assessed before and after the training course. Participants were randomly assigned to either: low-temperature lighting (LOW, n = 19), standard-temperature lighting with a placebo "sleep-enhancing" device (PLA, n = 17), or standard-temperature lighting (CON, n = 28) groups in their military barracks for the duration of the course. Repeated-measures ANOVAs were run to identify significant differences with post hoc analyses and effect size calculations performed where indicated. No significant interaction effect was observed for the sleep metrics; however, there was a significant effect of time for average sleep duration, and small benefits of LOW when compared with CON (d = 0.41-0.44). A significant interaction was observed for the 2.4-km run, with the improvement in LOW (Δ92.3 s) associated with a large improvement when compared with CON (Δ35.9 s; p = 0.003; d = 0.95 ± 0.60), but not PLA (Δ68.6 s). Similarly, curl-up improvement resulted in a moderate effect in favour of LOW (Δ14 repetitions) compared with CON (Δ6; p = 0.063; d = 0.68 ± 0.72). Chronic exposure to low-temperature lighting was associated with benefits to aerobic fitness across a 6-week training period, with minimal effects on sleep measures.

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.

A Multidisciplinary Approach to Game Day Preparation for Team Sports: A Delphi Study With Expert Consensus.

ABSTRACT: Mason, BRJ, Pumpa, KL, McKune, AJ, Gill, ND, and Ball, NB. A multidisciplinary approach to game day preparation for team sports: A Delphi study with expert consensus. J Strength Cond Res 36(5): 1345-1352, 2022-The aim of this study was to identify game day preparation strategies used by performance staff to improve team sport performance and to determine consensus regarding the application and importance of these strategies. Twenty-five performance staff working in high performance or professional team sports participated in this Delphi study, which implemented 3 survey rounds. The first round sought responses to open-ended questions relating to the use of game day preparation strategies. These responses were developed into statements and recirculated (round-2 survey), with subjects asked to rate their level of agreement with each statement. The third and final survey presented revised versions of statements that did not reach a consensus in the previous round, along with new statements derived from subject responses. A thematic analysis of the open-ended responses in the first survey identified 5 key themes relating to game day preparation strategies: "exercise," "nutrition," "psychological," "technical and tactical," and "other." The round-2 survey included 38 statements across the 5 themes, with 22 reaching the consensus threshold (≥75%) for agreement. The remaining 16 statements did not reach consensus. The final survey included 18 statements (16 revised and 2 new) with 12 reaching the consensus threshold for agreement. Key preparation strategies identified in this study include structured and progressive warm-ups, strength and power-based priming sessions, individualized nutrition plans, and precooling in hot conditions. Performance staff working in similar environments should consider adopting these strategies to improve athlete or team performance.

Sleep duration and physical performance during a 6-week military training course.

Sleep is vital in influencing effective training adaptations in the military. This study aimed to assess the relationship between sleep and changes in physical performance over 6 weeks of military training. A total of 22 officer-trainees (age: 24 ± 5 years) from the New Zealand Defence Force were used for this prospective cohort study. Participants wore wrist-actigraphs to monitor sleep, completed subjective wellbeing questionnaires weekly, and were tested for: 2.4-km run time-trial, maximum press-up and curl-ups before and after 6 weeks of training. Average sleep duration was calculated over 36 nights (6:10 ± 0:28 hr:min), and sleep duration at the mid-point (6:15 hr:min) was used to stratify the trainees into two quantile groups (UNDERS: 5:51 ± 0:29 hr:min, n = 11) and (OVERS: 6:27 ± 0:09 hr:min, n = 11). There were no significant group × time interactions for 2.4-km run, press-ups or curl-ups (p > .05); however, small effects were observed in favour of OVERS for 2.4-km run (59.8 versus 44.9 s; d = 0.26) and press-ups (4.7 versus 3.2 reps; d = 0.45). Subjective wellbeing scores resulted in a significant group × time interaction (p < .05), with large effect sizes in favour of the OVERS group for Fatigue in Week 1 (d = 0.90) and Week 3 (d = 0.87), and Soreness in Week 3 (d = 1.09) and Week 4 (d = 0.95). Sleeping more than 6:15 hr:min per night over 6 weeks was associated with small benefits to aspects of physical performance, and moderate to large benefits on subjective wellbeing measures when compared with sleeping < 6:15 hr:min.

Implementation and Efficacy of Plyometric Training: Bridging the Gap Between Practice and Research.

ABSTRACT: Watkins, CM, Storey, A, McGuigan, M, and Gill, ND. Implementation and efficacy of plyometric training: Bridging the gap between practice and research. J Strength Cond Res 35(5): 1244-1255, 2021-Plyometric training is an effective method for improving speed and acceleration. However, a gap seems to exist between research recommendations and practitioner's actual programs. Some reports suggest as many as 400 jumps per session, while anecdotally some strength and conditioning coaches are using as few as 15-40 jumps even with elite athletes. Thus, the purposes of this study were to obtain a clearer understanding of the practitioner's perspective on plyometric training strategies as compared to literary recommendations and to compare any trends across competition level or sport categories. An integrative mixed-methods model was used. Globally, 61 strength and conditioning practitioners completed an anonymous online survey, containing 5 sections: 1. Sport and coaching background information, 2. Plyometric training focus, 3. Periodization strategy, 4. Plyometric program details, and 5. Efficacy of plyometrics for sport performance. Questions included yes/no, multiple choice, Likert scale, percentage-based, and open-ended questions. The majority (70.5%) of respondents reported regularly implementing plyometric training and overwhelmingly (96.7%) reported positive athlete feedback surrounding its perceived efficacy. Findings confirmed that many practitioners regularly use significantly lower session volumes than previous literary recommendations (p < 0.05). In addition, significant differences were noted in many program details across competition level and sport category including volume periodization, exercise choice, and plyometric intensity. Practitioners may want to reflect on these reported group differences when building training programs best suited for their athletes. Meanwhile, future research should consider these reported perspectives when formulating interventions in attempts of bridging the gap between practice and theory.

Horizontal Force-Velocity-Power Profiling of Rugby Players: A Cross-Sectional Analysis of Competition-Level and Position-Specific Movement Demands.

ABSTRACT: Watkins, CM, Storey, A, McGuigan, MR, Downes, P, and Gill, ND. Horizontal force-velocity-power profiling of rugby players: A cross-sectional analysis of competition-level and position-specific movement demands. J Strength Cond Res 35(6): 1576-1585, 2021-Speed and acceleration are crucial to competitive success in all levels of rugby union. However, positional demands affect an athlete's expression of force and velocity during the match. This study investigated maximal sprint performance and horizontal force-velocity (FV) profiles in 176 rugby union players participating in amateur club, professional, and international competitions. Rugby players were divided into 5 positional groups: tight-5 forwards (n = 63), loose forwards (n = 35), inside backs (n = 29), midbacks (n = 22), and outside (n = 27) backs. Sprint performance was averaged across 2 trials of a maximal 30-m sprint, separated by a 3-minute rest. The results demonstrated differences in sprint performance and FV profile characteristics across competitions and positional groups. Specifically, both international and professional players possessed significantly faster split times and superior FV profiles than club players (p < 0.01; effect size [ES]: 0.22-1.42). International players were significantly faster across 0-10 m than professional players (p = 0.03; ES: 0.44-0.47), whereas professional players had faster 10-20 m times (p = 0.03; ES: 0.37-0.41) and a more force-dominant profile (p < 0.01; ES: 0.71-1.00). Across positions, split times decreased and maximal velocity characteristics increased in proportion with increasing positional number, with outside backs being the fastest (ES: 0.38-2.22). On the other hand, both forwards groups had more force-dominant profiles and average sprint momentum across all distances than all backs positions. Interestingly, loose forwards had a more forceful profile and slower 10-, 20-, and 30-m split times but similar maximal velocity characteristics to inside backs, highlighting unique positional demands and physical attributes.

The Effect of Low-Volume Preseason Plyometric Training on Force-Velocity Profiles in Semiprofessional Rugby Union Players.

ABSTRACT: Watkins, CM, Gill, ND, Maunder, E, Downes, P, Young, JD, McGuigan, MR, and Storey, AG. The effect of low-volume preseason plyometric training on force-velocity profiles in semiprofessional rugby union players. J Strength Cond Res 35(3): 604-615, 2021-Rugby union is a physically demanding and complex team sport requiring athletes across all positions to express speed and acceleration. Plyometrics can effectively improve speed profiles by enhancing both force- and velocity-(FV) characteristics; however, the optimal dose and exercise direction for trained athletes is still relatively unknown. Therefore, the aim of this investigation was to determine the efficacy of a low-dose, directionally specific plyometric training program for improving speed profiles in semiprofessional rugby players. Players were randomly allocated to one of 2 plyometric training groups that performed low-volume (40-60 ground contacts per session) plyometrics twice weekly, or a control group that did not participate in any plyometric training. The 2 training groups underwent reverse back-to-back three-week vertically and horizontally focused plyometric training programs, with a 12-day washout. Body composition, aerobic capacity, and sprint performance (10-, 20-, 30-m split time, horizontal FV profile) were measured. During the intervention, HV-1 (horizontal/vertical training group 1) improved sprint performance (n = 12; ∆30 m = -0.020 seconds; p = 0.038), VH-2 (vertical/horizontal training group 2) maintained sprint performance (n = 8; ∆30 m = +0.049 seconds; p = 0.377), and the control group progressively declined in sprint performance (n = 12; ∆30 m = +0.071; p = 0.019). In addition, vertical plyometrics may preferentially benefit secondary acceleration (∆10-20 m split time: -0.01 seconds; p = 0.03) and many force-oriented FV profile characteristics. Correlational analyses (r2 = -0.568 to 0.515) showed sprint improvements were hindered in athletes with lower initial aerobic fitness, suggesting accumulated fatigue may have limited the magnitude of adaptation. Therefore, including low-volume plyometric training may be beneficial for improving sprint profiles or attenuating decrements realized during periods of high-volume sport-specific training.

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.

Relationships Between Concentric and Eccentric Strength and Countermovement Jump Performance in Resistance Trained Men.

Bridgeman, LA, McGuigan, MR, Gill, ND, and Dulson, DK. Relationships between concentric and eccentric strength and countermovement jump performance in resistance trained men. J Strength Cond Res 32(1): 255-260, 2018-The purpose of this study was to investigate the relationships between concentric and eccentric peak force (PF) and countermovement jump (CMJ) performance in resistance trained men. Subjects were 12 men (mean ± SD; age: 25.4 ± 3.5 years; height: 177.2 ± 4.5 cm; mass: 84.0 ± 10.1 kg). The men were tested for concentric and eccentric PF using the Exerbotics squat device. Subjects then completed 3 CMJs to allow for the calculation of peak power (PP), peak ground reaction force, and jump height (JH). Correlations between the variables of interest were calculated using Pearson product-moment correlation coefficients. A large relationship was found between absolute concentric PF and absolute CMJ PP (r = 0.66, p ≤ 0.05). Absolute eccentric PF had a very large relationship with absolute CMJ PP and CMJ JH (r = 0.74, p < 0.01 and r = 0.74, p < 0.001, respectively). In addition, absolute eccentric PF was found to have a moderate relationship with relative CMJ PP (r = 0.58, p ≤ 0.05). Relative eccentric PF was had a very large relationship with relative CMJ PP and CMJ JH (r = 0.73, p < 0.001 and r = 0.79, p < 0.001, respectively). Based on these findings, strength and conditioning coaches and athletes who wish to enhance CMJ performance may wish to include exercises, which enhance lower-body eccentric strength within their training.

The Effect of Exercise-Induced Muscle Damage After a Bout of Accentuated Eccentric Load Drop Jumps and the Repeated Bout Effect.

Bridgeman, LA, Gill, ND, Dulson, DK, and McGuigan, MR. The effect of exercise induced muscle damage after a bout of accentuated eccentric load drop jumps and the repeated bout effect. J Strength Cond Res 31(2): 386-394, 2017-Although previous studies have investigated exercise-induced muscle damage (EIMD) after a bout of unloaded drop jumps (DJs), none have investigated the effects of accentuated eccentric load (AEL) DJs on EIMD. The purpose of this study was to investigate the effects of 30 and 50 AEL DJs on strength, jump performance, muscle soreness, and blood markers. Eight resistance trained athletes participated in this study. In week 1, baseline countermovement jump (CMJ), squat jump (SJ), concentric and eccentric peak force (PF), creatine kinase, and muscle soreness were assessed. Subjects then completed 30 AEL DJs and baseline measures were retested immediately postintervention, 1, 24, and 48 hours later. Two weeks later, the subjects completed the same protocol with an increase in AEL DJ volume (50). Subjects' SJ height was reduced in week 1 compared with week 3, postintervention, 1, 24, and 48 hours later (ES = -0.34, -0.44, -0.38, and -0.40). Subjects' CMJ height was reduced in week 1 compared with week 3, postintervention, 1, and 24 hours later (ES = -0.37, -0.29, and -0.39). Concentric PF was reduced in week 1 compared with week 3, postintervention and 24 and 48 hours later (ES = -0.02, -0.23, and -0.32). Eccentric PF was reduced in week 1 compared with week 3, postintervention, 24, and 48 hours later (ES = -0.24, -0.16, and -0.50). In this sample, 30 AEL DJs attenuated the effects of EIMD following which 50 AEL DJs completed 2 weeks later.

The Effects of Accentuated Eccentric Loading on the Drop Jump Exercise and the Subsequent Postactivation Potentiation Response.

The aims of this study were (a) to investigate the acute effects of different drop jump (DJ) accentuated eccentric loading (AEL) protocols and (b) to investigate the effect of these AEL DJ protocols on subsequent countermovement jump (CMJ) performance. The subjects were 12 strength-trained athletes; initially, baseline CMJ performance was assessed and individual optimal DJ drop height identified. In subsequent weeks, subjects completed 1 set of 5 DJs with no additional load or an AEL of 10, 20, or 30% of their individual body mass (BM) using dumbbells to provide the extra load. After the AEL DJ protocols, 3 CMJs were completed after 2, 6, and 12 minutes rest. A generalized linear mixed model was used to investigate the effects of AEL load and time post-DJs on CMJ height, peak power, and ground reaction force. The 20% AEL condition resulted in greater CMJ height in comparison with all other conditions (p < 0.001). CMJ height was significantly greater after 2 and 6 minutes rest compared with 12 minutes (p < 0.001 and p ≤ 0.05 respectively). Greater peak power was also found during the CMJs after the 20% AEL condition compared with baseline, BM, and 10% AEL (p ≤ 0.05). In conclusion, 5 DJs with 20% AEL followed by a 2 minutes recovery period resulted in significant enhancement in CMJ height and peak power.

Test-Retest Reliability of a Novel Isokinetic Squat Device With Strength-Trained Athletes.

Bridgeman, LA, McGuigan, MR, Gill, ND, and Dulson, DK. Test-retest reliability of a novel isokinetic squat device with strength-trained athletes. J Strength Cond Res 30(11): 3261-3265, 2016-The aim of this study was to investigate the test-retest reliability of a novel multijoint isokinetic squat device. The subjects in this study were 10 strength-trained athletes. Each subject completed 3 maximal testing sessions to assess peak concentric and eccentric force (N) over a 3-week period using the Exerbotics squat device. Mean differences between eccentric and concentric force across the trials were calculated. Intraclass correlation coefficients (ICCs) and coefficients of variation (CVs) for the variables of interest were calculated using an excel reliability spreadsheet. Between trials 1 and 2 an 11.0 and 2.3% increase in mean concentric and eccentric forces, respectively, was reported. Between trials 2 and 3 a 1.35% increase in the mean concentric force production and a 1.4% increase in eccentric force production was reported. The mean concentric peak force CV and ICC across the 3 trials was 10% (7.6-15.4) and 0.95 (0.87-0.98) respectively. However, the mean eccentric peak force CV and ICC across the trials was 7.2% (5.5-11.1) and 0.90 (0.76-0.97), respectively. Based on these findings it is suggested that the Exerbotics squat device shows good test-retest reliability. Therefore practitioners and investigators may consider its use to monitor changes in concentric and eccentric peak force.

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.

The training effect of short term enhancement from complex pairing on horizontal and vertical countermovement and drop jump performance.

The purpose of this study was to investigate the chronic effect of a contrast training program designed to elicit an acute short term enhancement (STE) effect during training. A matched pairs training study design was implemented with a contrast (STE affected) and complex (control) training group completing a seven week training intervention. Twenty subjects participated. The contrast training group completed training based on a preloading protocol that had previously been shown to induce an acute STE effect within the subject population. The control group completed the same volume and type of training in a complex training format. Changes in squat 4RM strength and kinetic and kinematic performance in vertical and horizontal countermovement jump (CMJ) and drop jump (DJ) were measured via a Force Plate. Differences between the experimental and control group in change of mean strength (effect size 0.03 ± 0.33), vertical DJ (effect size: contact time -0.22 ± 0.52; peak force 0.20 ± 0.30; mean force 0.30 ± 0.74) and horizontal DJ (effect size: contact time -0.47 ± 0.73; peak force 0.03 ± 0.36; mean force 0.13 ± 0.56) were not meaningful. However, differences in mean change of vertical and horizontal CMJ measures of force (effect size range 0.40 - 0.46 ± 0.37 - 0.63), vertical CMJ peak velocity (effect size 0.84 ±0.66) and mean velocity (0.62 ± 0.88) were meaningful. These findings demonstrate that eliciting an acute STE response in dynamic training movements through contrast training can produce a chronic improvement in dynamic movements as a training effect.

Relationship between vertical and horizontal jump variables and muscular performance in athletes.

This study investigated the relationship between vertical and horizontal measures in bilateral and unilateral countermovement jump, drop jump and squat jump (SJ), and sprinting speed and muscle architecture of both the vastus lateralis and gastrocnemius. Subjects (n = 17) completed a 30-m sprint test, muscle stiffness test; ultrasound measures, and a jump testing session. Measures of horizontal peak and mean force, in both bilateral and unilateral jumps, tended to have greater relationships to sprint speeds (R = 0.132-0.576) than peak and mean force in the vertical plane (R = 0.008-0.504). Vertical velocity variables also showed some large and very large correlations to sprint speed (R = 0.062-0.635). Unilateral measures of velocity tended to have larger correlations to sprint performance than their bilateral counterparts across all jump types and peak and mean velocity in SJ showed large and very large correlations to sprint speed (bilateral R = 0.227-0.635; unilateral 0.393-0.574). Few large correlations were shown between muscle stiffness measures of muscle architecture and kinetic and kinematic variables in either vertical or horizontal jumps. The present findings suggest that sport scientists and strength and conditioning practitioners concerned with the prognostic value of kinetic variables to functional movements such as sprint speed should also use horizontal jumps in addition to vertical jumps in testing and training.

Strongman vs. traditional resistance training effects on muscular function and performance.

Currently, no evidence exists as to the effectiveness of strongman training programs for performance enhancement. This study compared the effects of 7 weeks of strongman resistance training vs. traditional resistance training on body composition, strength, power, and speed measures. Thirty experienced resistance-trained rugby players were randomly assigned to one of the 2 groups; strongman (n = 15; mean ± SD: age, 23.4 ± 5.6 years; body mass, 91.2 ± 14.8 kg; height, 180.1 ± 6.8 cm) or traditional (n = 15; mean ± SD: age, 22.5 ± 3.4 years; body mass, 93.7 ± 12.3 kg; height, 181.3 ± 5.9 cm). The strongman and traditional training programs required the participants to train twice a week and contained exercises that were matched for biomechanical similarity with equal loading. Participants were assessed for body composition, strength, power, speed, and change of direction (COD) performance. Within-group analyses indicated that all performance measures improved with training (0.2-7%) in both the strongman and traditional training groups. No significant between-group differences were observed in functional performance measures after 7 weeks of resistance training. Between-group differences indicated small positive effects in muscle mass and acceleration performance and large improvements in 1 repetition maximum (1RM) bent over row strength associated with strongman compared with traditional training. Small to moderate positive changes in 1RM squat and deadlift strength, horizontal jump, COD turning ability, and sled push performance were associated with traditional compared with strongman training. Practitioners now have the first evidence on the efficacy of a strongman training program, and it would seem that short-term strongman training programs are as effective as traditional resistance training programs in improving aspects of body composition, muscular function, and performance.

Small-sided games for young athletes: is game specificity influential?

This study aimed to quantify and compare the physiological, physical and technical demands of a sport-specific and non-sport-specific small-sided game (SSG) in young athletes. Ten male soccer players (mean ± SD: age, 13.0 ± 0.3 years, [Formula: see text]O2peak, 54.4 ± 4.9 ml · kg(-1) · min(-1)) completed 3 vs. 3 and 6 vs. 6 soccer and "bucketball" SSGs twice. Games lasted for 16 min and were performed in a randomised order, at least 48 h apart. Movement patterns and heart rate were measured using 4 Hz global positioning systems. Technical skill executions were assessed by video analysis and ratings of perceived exertion (RPE) using the Borg scale (RPEs, 6-20). Total distance (4.9 ± 4.1% and 8.3 ± 6.6%), distance at 7-12.9 km · h(-1) (14.5 ± 12.5% and 14.9 ± 16.1%), total possessions (14.7 ± 18.0% and 12.9 ± 18.9%) and percentage of successful passes (24.1 ± 11.7% and 30.1 ± 17.6%) were higher for bucketball compared to soccer (3 vs. 3 and 6 vs. 6, respectively). Total distance at 13-17.9 km · h(-1) was higher for 6 vs. 6 than 3 vs. 3 bucketball (32.3 ± 21.2%). There was likely substantial difference for %HRpeak (89.5 ± 3.1 vs. 87.4 ± 2.8 b · min(-1)) and time above 90% HRpeak (570 ± 288 s vs. 361 ± 288 s) between bucketball and soccer (3 vs. 3 and 6 vs. 6, respectively). Young players travelled further at higher overall speeds, experienced higher physiological workloads and performed more successful technical executions during the non-sport-specific SSG.

Assessing the variation in the load that produces maximal upper-body power.

Substantial variation in the load that produces maximal power has been reported. It has been suggested that the variation observed may be due to differences in subjects' physical characteristics. Therefore, the aim of this study was to determine the extent in which anthropometric measures correlate with the load that produces maximal power. Anthropometric measures (upper-arm length, forearm length, total arm length, and upper-arm girth) and bench press strength were assessed in 26 professional rugby union players. Peak power was then determined in the bench press throw exercise using loads of 20-60% of one repetition maximum (1RM) in the bench press exercise. Maximal power occurred at 30 ± 14% 1RM (mean ± SD). Upper-arm length had the highest correlation with the load maximizing power: -0.61 (90% confidence limits -0.35 to -0.78), implying loads of 22 vs. 38% 1RM maximize power for players with typically long vs. short upper-arm length. Correlations for forearm length, total arm length, and upper-arm girth to the load that maximized power were -0.29 (0.04 to -0.57), -0.56 (-0.28 to -0.75), and -0.29 (0.04 to -0.57), respectively. The relationship between 1RM and the load that produced maximal power was r = -0.23 (0.10 to -0.52). The between-subject variation in the load that maximized power observed (SD = ±14% of 1RM) may have been due to differences in anthropometric characteristics, and absolute strength and power outputs. Indeed, athletes with longer limbs and larger girths and greater maximal strength and power outputs used a lower percentage of 1RM loads to achieve maximum power. Therefore, we recommend individual assessment of the load that maximizes power output.

Kinetic Analysis, Potentiation, and Fatigue During Vertical and Horizontal Plyometric Training: An In-Depth Investigation Into Session Volume.

Despite previous support for plyometric training, optimal dosing strategies remain unclear. PURPOSE: To investigate vertical and horizontal jump kinetic performance following a low-volume plyometric stimulus with progressively increased session jump volume. METHODS: Sixteen academy rugby players (20.0 [2.0] y; 103.0 [17.6] kg; 184.3 [5.5] cm) volunteered for this study. Vertical and horizontal jump sessions were conducted 1 week apart and consisted of a 40-jump low-volume plyometric stimulus using 4 exercises, after which volume was progressively increased to 200 jumps, using countermovement jump (CMJ) for vertical sessions and horizontal broad jump (HBJ) for horizontal sessions. Jump performance was assessed via force-plate analysis at baseline (PRE-0), following the low-volume plyometric stimulus (P-40), and every subsequent 10 jumps until the end of the session (P-50, P-60, P-70, ... P-200). RESULTS: The low-volume stimulus was effective in potentiating HBJ (2% to 5%) but not CMJ (0% to -7%) performance (P < .001). The HBJ performance enhancements were maintained throughout the entire high-volume session, while CMJ realized small but significant decrements (-5% to -7%) in jump height P-50 to P-80 before recovering to presession values. Moreover, increases in eccentric impulse (5% to 24%; P < .001) in both sessions were associated with decreased or maintained concentric impulse, indicating a breakdown in performance-augmenting mechanisms and less effective power transfer concentrically after moderate volumes. CONCLUSION: Practitioners should consider kinetic differences between HBJ and CMJ with increasing volume to better inform and understand session dosing strategies.

Effects of an off-season conditioning program on the physical characteristics of adolescent rugby union players.

The aims of the study were to determine if a supervised off-season conditioning program enhanced gains in physical characteristics compared with the same program performed in an unsupervised manner and to establish the persistence of the physical changes after a 6-month unsupervised competition period. Forty-four provincial representative adolescent rugby union players (age, mean ± SD, 15.3 ± 1.3 years) participated in a 15-week off-season conditioning program either under supervision from an experienced strength and conditioning coach or unsupervised. Measures of body composition, strength, vertical jump, speed, and anaerobic and aerobic running performance were taken, before, immediately after, and 6 months after the conditioning. Post conditioning program the supervised group had greater improvements in all strength measures than the unsupervised group, with small, moderate and large differences between the groups\x{2019} changes for chin-ups (9.1%; ± 11.6%), bench-press (16.9%; ± 11.7%) and box-squat (50.4%; ± 20.9%) estimated 1RM respectively. Both groups showed trivial increases in mass; however increases in fat free mass were small and trivial for supervised and unsupervised players respectively. Strength declined in the supervised group while the unsupervised group had small increases during the competition phase, resulting in only a small difference between the long-term changes in box-squat 1RM (15.9%; ± 13.2%). The supervised group had further small increases in fat free mass resulting in a small difference (2.4%; ± 2.7%) in the long-term changes. The postconditioning differences between the 2 groups may have been a result of increased adherence and the attainment of higher training loads during supervised training. The lack of differences in strength after the competition period indicates that supervision should be maintained to reduce substantial decrements in performance.