The Effect of a Heavy Resisted Sled-Pull Mesocycle on Sprint Performance in Junior Australian Football Players.

ABSTRACT: Edwards, T, Piggott, B, Banyard, HG, Haff, GG, and Joyce, C. The effect of a heavy resisted sled-pull mesocycle on sprint performance in junior Australian football players. J Strength Cond Res 37(2): 388-393, 2023-This study assessed the effect of heavy resisted sled-pull training on sprint times and force, velocity, and power characteristics in junior Australian football players. Twenty-six athletes completed a 6-week resisted sled-pull training intervention which included 10 training sessions and 1-week taper. Instantaneous velocity during 2 maximal 30 m sprints was recorded 1 week before and 1 week after the intervention with a radar gun. Velocity-time data were used to derive sprint performance and force, velocity, and power characteristics. A paired t -test assessed the within-group differences between preintervention and postintervention testing. Statistical significance was accepted at p ≤ 0.05. Hedges' g effect sizes (ESs) were used to determine the magnitude of change in dependent variables. Maximum velocity (ES = 1.33) and sprint times at all distances (ES range 0.80-1.41) significantly improved after heavy resisted sled-pull training. This was reflected in sprint force, velocity, and power characteristics with significant improvements in relative theoretical force (ES = 0.63), theoretical velocity (ES = 0.99), relative maximum power (ES = 1.04), and ratio of horizontal to vertical force (ES = 0.99). Despite the multifactorial nature of training and competing physical demands associated with preseason training, these findings imply that a short, resisted sled-pull training mesocycle may improve sprint performance and underlying force, velocity, and power characteristics in junior athletes.

Longitudinal Development of Sprint Performance and Force-Velocity-Power Characteristics: Influence of Biological Maturation.

ABSTRACT: Edwards, T, Weakley, J, Banyard, HG, Cripps, A, Piggott, B, Haff, GG, and Joyce, C. Longitudinal development of sprint performance and force-velocity-power characteristics: influence of biological maturation. J Strength Cond Res 37(11): 2178-2184, 2023-This study was designed to investigate the influence of biological maturation on the longitudinal development of sprint performance. Thirty-two subjects performed 2 assessments of maximal sprint performance that were separated by 18 months. Each sprint assessment was measured through a radar gun that collected instantaneous velocity with the velocity-time data used to derive sprint times and force-velocity-power characteristics. The biological maturity of each subject was assessed using a predictive equation, and subjects were grouped according to predicted years from peak height velocity (circa-PHV: -1.0 to 1.0; post-PHV: >1.0). A 2 × 2 mixed model analysis of variance was used to assess group × time interactions, and paired t -tests were used to assess the longitudinal changes for each maturity group. No significant group × time interactions were observed for any sprint time or force-velocity-power characteristic. The circa-PHV group experienced significant within-group changes in maximal theoretical velocity (6.35 vs. 5.47%; effect size [ES] = 1.26 vs. 0.52) and 5-m sprint time (-3.63% vs. -2.94%; ES = -0.64 vs. -0.52) compared with the post-PHV group. There was no significant change in the magnitude of relative theoretical maximum force in either group; however, both the circa-PHV and post-PHV groups significantly improved the orientation of force production at the start of the sprint (RFmax [4.91 vs. 4.46%; ES = 0.79 vs. 0.74, respectively]). Considering these findings, it is recommended that practitioners adopt training methods aimed to improve relative lower-limb force production, such as traditional strength training and sled pulling and pushing, to improve sprint performance and relative theoretical maximum force.

Effect of Traditional, Rest Redistribution, and Velocity-Based Prescription on Repeated Sprint Training Performance and Responses in Semiprofessional Athletes.

ABSTRACT: Weakley, J, Castilla, AP, Ramos, AG, Banyard, H, Thurlow, F, Edwards, T, Morrison, M, McMahon, E, and Owen, C. The effect of traditional, rest redistribution, and velocity-based prescription on repeated sprint training performance and responses in semi-professional athletes. J Strength Cond Res 37(8): 1566-1572, 2023-The aim of this study was to investigate the effects of traditional, rest redistribution, and velocity-based repeated sprint training methods on repeated sprint performance, perceived effort, heart rate, and changes in force-velocity-power (FVP) profiles in male semiprofessional athletes. In a randomized crossover design, a traditional (2 sets of 6 repetitions [TRAD]), 2 different rest redistribution (4 sets of 3 repetitions [RR4] and 12 sets of 1 repetition [RR12]), and a 5% velocity loss (VL5%) (12 repetitions, with sets terminated when a 5% reduction in mean velocity had occurred) condition were completed. Mean and peak velocity, mean heart rate, and differential ratings of perceived exertion (dRPE) were measured throughout each session, while horizontal FVP profiles were assessed presession and postsession. The RR4 and RR12 conditions allowed the greatest maintenance of velocity, while the RR4, RR12, and VL5% had a moderate , significantly greater mean heart rate than the traditional condition. Trivial , nonsignificant differences between all conditions were observed in dRPE of the legs and breathlessness and FVP profiles. These findings indicate that rest redistribution can allow for greater maintenance of sprint velocity and heart rate, without altering perceived effort during repeated sprint training. In addition, velocity-loss thresholds may be a feasible method of prescription if athletes have diverse physical qualities and reductions in sprint performance during repeated sprint training are undesirable. Practitioners should consider these outcomes when designing repeated sprint training sessions because the strategic use of these methods can alter sprint performance and internal load without changing perceptions of intensity.

Comparison of Countermovement Jump and Squat Jump Performance Between 627 State and Non-State Representative Junior Australian Football Players.

ABSTRACT: Edwards, T, Weakley, J, Woods, CT, Breed, R, Benson, AC, Suchomel, TJ, and Banyard, HG. Comparison of countermovement jump and squat jump performance between 627 state and non-state representative junior Australian football players. J Strength Cond Res 37(3): 641-645, 2023-This cross-sectional study investigated differences in lower-body power of state and nonstate representative junior Australian football (AF) players through countermovement jump (CMJ) and squat jump (SJ) performance. A total of 627 players performed the CMJ and SJ at the end of the preseason phase over a 2-week period, with each player grouped according to their age (under 18 [U18] or under 16 [U16]), and highest competition level played (state representation and nonstate representation). One-way multivariate analysis of variance (MANOVA), follow up ANOVA's, and Cohen's d effect sizes were used to identify significant main effects and between-group differences. Statistical significance was set at α < 0.05. Significant small-to-moderate effect size differences were observed between competition level, with state U18 and U16 players recording greater CMJ and SJ height, and peak power (PP), compared with their nonstate representative peers, respectively. Similarly, significant small-to-moderate effect size differences existed between age groups, with nonstate U18 players recording greater CMJ and SJ height and PP than nonstate U16 counterparts. However, state U18 and state U16 only differed in CMJ PP. No differences were found between competition level or age groups for the difference between CMJ and SJ jump height (CMJSJ diff ). Together, these findings suggest that state and nonstate representative junior AFs may have a similar ability to use the stretch-shortening cycle, despite state representative players jumping higher in the CMJ and SJ.

Reliability and Minimal Detectable Change of Sprint Times and Force-Velocity-Power Characteristics.

ABSTRACT: Edwards, T, Banyard, HG, Piggott, B, Haff, GG, and Joyce, C. The reliability and minimal detectable change of sprint times and force-velocity-power characteristics. J Strength Cond Res 36(1): 268-272, 2022-Research has not yet provided critical information for practitioners to determine the minimal detectable change (MDC) in sprint times or force-velocity-power characteristics. Therefore, the aim of this study was to establish the interday reliability and MDC of sprint times and sprint force-velocity-power characteristics in junior Australian football (AF) players. Seventeen players were assessed using a radar device that recorded instantaneous velocity during 3 maximal 30-m sprint accelerations performed on 2 nonconsecutive days. Sprint force, velocity, and power characteristics were derived through inverse dynamics applied to the raw velocity-time data. Relative and absolute reliability was determined by calculating the intraclass correlation coefficient (ICC), coefficient of variation (CV), and MDC. Data analysis was assessed for (a) the first trial, (b) the best trial (the fastest 30-m split time), (c) the average of the first 2 trials, and (d) the average of all 3 trials from each testing session. The main findings were (a) absolute theoretical maximum force (F0), theoretical maximal velocity (V0), absolute and relative maximum power (Pmax), maximum ratio of force (RFmax), maximum velocity (Vmax), and all sprint distance times (5-30 m) displayed acceptable reliability (CV < 10% and ICC >0.75) and 2) the average of 2 and 3 trials was the best method of establishing reliable sprint times and force-velocity-power characteristics between sessions. This study provides important information for practitioners to determine the MDC in sprint times and force-velocity-power characteristics that allow coaches to identify true changes in performance.

Influence of age and maturation status on sprint acceleration characteristics in junior Australian football.

This study aimed to investigate the influence of chronological age and maturation status on sprint acceleration characteristics in junior Australian football (AF) players. Biological maturity of 109 subjects was assessed and subjects were grouped according to predicted years from peak height velocity (PHV) (pre-, mid-, and post-PHV) and chronological age (13 years, 14 years, and 15 years). A one-way multivariate analysis of variance and magnitude-based decisions were used to determine between-group differences. Instantaneous velocity was measured during two maximal 30m sprints via radar gun with the velocity-time data used to derive the force, velocity, and power characteristics. Chronologically, the greatest differences were observed between the 13 and 14 year old groups with the latter group producing likely greater relative maximum power (Pmax) (ES[effect size]=0.44) and theoretical maximal velocity (V0) (ES=0.49). The post-PHV group likely demonstrated a greater ability to apply force at faster velocity (V0; ES=0.59) and orient the force in a horizontal direction (Drf%; ES=-0.49) than the mid-PHV group. No differences in relative theoretical maximal force (F0) were observed between groups. Considering the findings, practitioners should aim to improve relative lower limb strength through heavy sled push or sled pulls and traditional strength training exercises to improve relative F0.

Application of velocity loss thresholds during free-weight resistance training: Responses and reproducibility of perceptual, metabolic, and neuromuscular outcomes.

The aim of this study was to investigate the differences and long-term reliability in perceptual, metabolic, and neuromuscular responses to velocity loss resistance training protocols. Using a repeated, counterbalanced, crossover design, twelve team-sport athletes completed 5-sets of barbell back-squats at a load corresponding to a mean concentric velocity of ~0.70 m·s-1. On different days, repetitions were performed until a 10%, 20% or 30% velocity loss was attained, with outcome measures collected after each set. Sessions were repeated after four-weeks. There were substantial between-protocol differences in post-set differential ratings of perceived exertion (dRPE, i.e., breathlessness and leg muscles, AU) and blood lactate concentration (B[La], mmol·L-1), such that 30%>20%>10% by small to large magnitudes. Differences in post-set countermovement jump (CMJ) variables were small for most variables, such that 30%<20%<10%. Standard deviations representing four-week variability of post-set responses to each protocol were: dRPE, 8-11; B[La], 0.8-1.0; CMJ height, 1.6-2.0; CMJ PPO, 1.0-1.8; CMJ PCV, 0.04-0.06; CMJ 100ms-Impulse, 5.7-11.9. Velocity loss thresholds control the magnitude of perceptual, metabolic, and neuromuscular responses to resistance training. For practitioners wanting to reliably prescribe training that can induce a given perceptual, metabolic, or neuromuscular response, it is strongly advised that velocity-based thresholds are implemented.

Validity and Reliability of Methods to Determine Barbell Displacement in Heavy Back Squats: Implications for Velocity-Based Training.

Appleby, BB, Banyard, H, Cormack, SJ, and Newton, RU. Validity and reliability of methods to determine barbell displacement in heavy back squats: Implications for velocity-based training. J Strength Cond Res 34(11): 3118-3123, 2020-The purpose of this study was to investigate the validity and reliability of methods for determining barbell displacement during heavy back squats. Twelve well-trained rugby union players (mean ± SD 1 repetition maximum [1RM] 90° squat = 196.3 ± 29.2 kg) completed 2 sets of 2 repetitions at 70, 80, and 90% of 1RM squats. Barbell displacement was derived from 3 methods across 4 load categories (120-129, 140-149, 160-169, and 180-189 kg) including: a (a) linear position transducer (LPT) attached 65 cm left of barbell center, (b) 3D motion analysis tracking of markers attached to either end of a barbell, and (c) cervical marker (C7) (criterion measurement). Validity was calculated using the typical error of the estimate as a coefficient of variation (CV%) ±90% confidence interval (CI), mean bias as a percentage, and the Pearson product moment correlation (r). Intraday reliability was calculated using the intraclass correlation coefficient and the typical error expressed as a percentage of CV% ±90% (CI). Mean displacement for C7, LPT, and the barbell ends was 520, 529, and 550-564 mm, respectively. Validity of the LPT compared with the criterion was acceptable (CV% = 2.1-3.0; bias = 0.9-1.5%; r = 0.96-0.98), whereas that of the barbell ends was less (CV% = 2.7-7.5; bias = 4.9-11.2%; r = 0.71-0.97). The CV% reliability of the C7 marker across the load categories was 6.6%, the LPT 6.6%, and the barbell ends between 5.9 and 7.2%. Despite reliable measures, overestimation of displacement occurs as the tracking location moves to the barbell ends in weighted back squats. The LPT demonstrated high validity to the criterion and high trial-to-trial reliability.

Show Me, Tell Me, Encourage Me: The Effect of Different Forms of Feedback on Resistance Training Performance.

Weakley, J, Wilson, K, Till, K, Banyard, H, Dyson, J, Phibbs, P, Read, D, and Jones, B. Show me, tell me, encourage me: The effect of different forms of feedback on resistance training performance. J Strength Cond Res 34(11): 3157-3163, 2020-When performing resistance training, verbal kinematic feedback and visual kinematic feedback are known to enhance performance. In addition, providing verbal encouragement can assist in the attenuation of fatigue. However, the effects of these forms of feedback have never been compared. Consequently, this study aimed to quantify the effects of verbal kinematic feedback and visual kinematic feedback, and verbal encouragement on barbell velocity during the back squat. Furthermore, changes in performance were related to individual-reported conscientiousness. Twelve semiprofessional rugby union players volunteered to participate in the study that consisted of the subjects completing a set of the barbell back squat across 4 conditions (i.e., no-feedback [control], verbal feedback of kinematic information [verbal], visual feedback of kinematic information [visual], and verbal encouragement [encouragement]). In addition, participants completed a questionnaire before the study to assess conscientiousness. Magnitude-based inferences were used to assess differences between conditions, whereas Spearman's rank correlation coefficient was used to assess relationships between conscientiousness and changes in barbell velocity. All 3 forms of feedback showed almost certain improvements in barbell velocity, while differences between interventions were likely to very likely trivial. Changes in barbell velocity showed small to large inverse relationships with conscientiousness. These findings suggest that practitioners should supply kinematic feedback (verbally or visually) or, when technology is not available, provide athletes with encouraging statements while resistance training. Verbal encouragement may be of greatest benefit for individuals who demonstrate low levels of conscientiousness. Given these findings, practitioners are advised to use either technology or verbal encouragement to manipulate acute training outcomes.

Comparison Between Back Squat, Romanian Deadlift, and Barbell Hip Thrust for Leg and Hip Muscle Activities During Hip Extension.

Delgado, J, Drinkwater, EJ, Banyard, HG, Haff, GG, and Nosaka, K. Comparison between back squat, Romanian deadlift, and barbell hip thrust for leg and hip muscle activities during hip extension. J Strength Cond Res 33(10): 2595-2601, 2019-This study compared muscle activities of vastus lateralis (VL), biceps femoris (BF), and gluteus maximus (GM) during the back squat (SQ), Romanian deadlift (RDL), and barbell hip thrust (BHT) exercises performed with the same load (60 kg) and at one repetition maximum (1RM). Eight men with a minimum of 1 year's lower-body strength training experience performed the exercises in randomized order. Before each exercise, surface electromyography (EMG) was recorded during a maximal voluntary isometric contraction (MVIC) and then used to normalize to each muscle's EMG during each trial. Barbell hip thrust showed higher GM activity than the SQ (effect size [ES] = 1.39, p = 0.038) but was not significantly different from RDL (ES = 0.49, p = 0.285) at 1RM. Vastus lateralis activity at 1RM during the SQ was significantly greater than RDL (ES = 1.36, p = 0.002) and BHT (ES = 2.27, p = 0.009). Gluteus maximus activity was higher during MVIC when compared with the 60 kg load for the SQ (ES = 1.29, p = 0.002) and RDL (ES = 1.16, p = 0.006) but was similar for the BHT (ES = 0.22, p = 0.523). There were no significant differences in GM (ES = 0.35, p = 0.215) and BF activities (ES = 0.16, p = 0.791) between 1RM and MVIC for the SQ. These findings show that the RDL was equally as effective as the BHT for isolating the hip extensors, while the SQ simultaneously activated the hip and knee extensors.

Using a Load-Velocity Relationship to Predict One repetition maximum in Free-Weight Exercise: A Comparison of the Different Methods.

Hughes, LJ, Banyard, HG, Dempsey, AR, and Scott, BR. Using a load-velocity relationship to predict one repetition maximum in free-weight exercise: a comparison of the different methods. J Strength Cond Res 33(9): 2409-2419, 2019-The purpose of this study was to investigate the reliability and validity of predicting 1 repetition maximum (1RM) in trained individuals using a load-velocity relationship. Twenty strength-trained men (age: 24.3 ± 2.9 years, height: 180.1 ± 5.9 cm, and body mass: 84.2 ± 10.5 kg) were recruited and visited the laboratory on 3 occasions. The load-velocity relationship was developed using the mean concentric velocity of repetitions performed at loads between 20 and 90% 1RM. Predicted 1RM was calculated using 3 different methods discussed in existing research: minimal velocity threshold 1RM (1RMMVT), load at zero velocity 1RM (1RMLD0), and force-velocity 1RM methods (1RMFV). The reliability of 1RM predictions was examined using intraclass correlation coefficient (ICC) and coefficient of variation (CV). 1RMMVT demonstrated the highest reliability (ICC = 0.92-0.96, CV = 3.6-5.0%), followed by 1RMLD0 (ICC = 0.78-0.82, CV = 8.2-8.6%) and 1RMFV (ICC = -0.28 to 0.00, CV = N/A). Both 1RMMVT and 1RMLD0 were very strongly correlated with measured 1RM (r = 0.91-0.95). The only method which was not significantly different to measured 1RM was the 1RMLD0 method. However, when analyzed on an individual basis (using Bland-Altman plots), all methods exhibited a high degree of variability. Overall, the results suggest that the 1RMMVT and 1RMLD0 predicted 1RM values could be used to monitor strength progress in trained individuals without the need for maximal testing. However, given the significant differences between 1RMMVT and measured 1RM, and the high variability associated with individual predictions performed using each method, they cannot be used interchangeably; therefore, it is recommended that predicted 1RM is not used to prescribe training loads as has been previously suggested.

Using Load-Velocity Relationships to Quantify Training-Induced Fatigue.

Hughes, LJ, Banyard, HG, Dempsey, AR, Peiffer, JJ, and Scott, BR. Using load-velocity relationships to quantify training-induced fatigue. J Strength Cond Res 33(3): 762-773, 2019-The purpose of this study was to investigate using load-velocity relationships to quantify fluctuations in maximal strength (1 repetition maximum [1RM]), which occur as a result of training-induced fatigue. The 19 well-trained men (age: 24.3 ± 2.9 years, height: 180.1 ± 5.9 cm, body mass: 84.2 ± 10.5 kg, and squat 1RM: 151.1 ± 25.7 kg) who were recruited for this study attended 5 sessions. After baseline strength testing, individual load-velocity relationships were established using mean concentric velocity during visits 2, 4, and 5, with visit 3 consisting of a bout of fatiguing exercise (5 sets of squats performed to muscular failure with 70% 1RM). Predicted 1RM values were calculated using the minimal velocity threshold (1RMMVT), load at zero velocity (1RMLD0), and force-velocity (1RMFV) methods. Measured 1RM, maximal voluntary contractions, and perceived muscle soreness were used to examine the effects of fatigue in relation to the predicted 1RM scores. The 1RMMVT and 1RMLD0 demonstrated very strong and strong correlations with measured 1RM during each of the sessions (r = 0.90-0.96 and r = 0.77-0.84, respectively), while no strong significant correlations were observed for the 1RMFV. Further analysis using Bland-Altman plots demonstrated substantial interindividual variation associated with each method. These results suggest that load-velocity-based 1RM predictions are not accurate enough to be used for daily training load prescription, as has been previously suggested. Nevertheless, these predictions are practical to implement during an individual's warm-up and may be useful to indicate general fluctuations in performance potential, particularly if used in conjunction with other common monitoring methods.

Manipulating Field Dimensions During Small-sided Games Impacts the Technical and Physical Profiles of Australian Footballers.

Brock, F, Christopher, J, Harry, B, and Carl, WT. Manipulating field dimensions during small-sided games impacts the technical and physical profiles of Australian footballers. J Strength Cond Res 32(7): 2039-2044, 2018-This study investigated the effect of manipulating field dimensions on the technical and physical profiles of Australian football (AF) players during small-sided games (SSGs). A total of 40 male players (23.9 ± 3.5 years) participated in 3, five-a-side SSGs; defined as "small" (20 × 30 m; 600 m), "medium" (30 × 40 m; 1,200 m), and "large" (40 × 50 m; 2,000 m). Notational analyses enabled the quantification of technical skill indicators, whereas physical activity profiles were measured using microtechnology, resulting in 18 criterion variables. A multivariate analysis of variance modeled the main effect of field dimension on the criterion variables. A significant main effect was observed (V = 1.032; F38, 102 = 2.863; p ≤ 0.05), with the "small" and "medium" SSGs generating more turnovers and ineffective handballs relative to the "large" SSG. Furthermore, the "small" SSG generated more tackles and fewer bounces compared with the "large" SSG. The "large" SSG generated a greater absolute distance, relative distance, maximum velocity, PlayerLoad, and distance >4.16 m·s compared with the "small" and "medium" SSGs. These results provide AF coaches with insights into how task constraint manipulation impacts the technical and physical profiles of players during small-sided game-play. Thus, coaches and physical performance specialists could use this information to assist with the tactical periodization of technical complexity and physical load at different phases of the AF season.

The efficacy of periodised resistance training on neuromuscular adaptation in older adults.

PURPOSE: This study compared the effect of periodised versus non-periodised (NP) resistance training on neuromuscular adaptions in older adults. METHODS: Forty-one apparently healthy untrained older adults (female = 21, male = 20; 70.9 ± 5.1 years; 166.3 ± 8.2 cm; 72.9 ± 13.4 kg) were recruited and randomly stratified to an NP, block periodised (BP), or daily undulating periodised (DUP) training group. Outcome measures were assessed at baseline and following a 22-week resistance training intervention (3 day week-1), including: muscle cross-sectional area (CSA), vertical jump performance, isometric and isokinetic peak torque, isometric rate of force development (RFD), and muscle activation. Thirty-three participants satisfied all study requirements and were included in analyses (female = 17, male = 16; 71.3 ± 5.4 years; 166.3 ± 8.5 cm; 72.5 ± 13.7 kg). RESULTS: Block periodisation, DUP, and NP resistance training induced statistically significant improvements in muscle CSA, vertical jump peak velocity, peak power and jump height, and peak isometric and isokinetic torque of the knee extensors at 60 and 180° s-1, with no between-group differences. Muscle activity and absolute RFD measures were statistically unchanged following resistance training across the entire cohort. CONCLUSIONS: Periodised resistance training, specifically BP and DUP, and NP resistance training are equally effective for promoting increases in muscular hypertrophy, strength, and power among untrained older adults. Consequently, periodisation strategies are not essential for optimising neuromuscular adaptations during the initial stages of resistance training in the aging population.

Reliability and Validity of the Load-Velocity Relationship to Predict the 1RM Back Squat.

Banyard, HG, Nosaka, K, and Haff, GG. Reliability and validity of the load-velocity relationship to predict the 1RM back squat. J Strength Cond Res 31(7): 1897-1904, 2017-This study investigated the reliability and validity of the load-velocity relationship to predict the free-weight back squat one repetition maximum (1RM). Seventeen strength-trained males performed three 1RM assessments on 3 separate days. All repetitions were performed to full depth with maximal concentric effort. Predicted 1RMs were calculated by entering the mean concentric velocity of the 1RM (V1RM) into an individualized linear regression equation, which was derived from the load-velocity relationship of 3 (20, 40, 60% of 1RM), 4 (20, 40, 60, 80% of 1RM), or 5 (20, 40, 60, 80, 90% of 1RM) incremental warm-up sets. The actual 1RM (140.3 ± 27.2 kg) was very stable between 3 trials (ICC = 0.99; SEM = 2.9 kg; CV = 2.1%; ES = 0.11). Predicted 1RM from 5 warm-up sets up to and including 90% of 1RM was the most reliable (ICC = 0.92; SEM = 8.6 kg; CV = 5.7%; ES = -0.02) and valid (r = 0.93; SEE = 10.6 kg; CV = 7.4%; ES = 0.71) of the predicted 1RM methods. However, all predicted 1RMs were significantly different (p ≤ 0.05; ES = 0.71-1.04) from the actual 1RM. Individual variation for the actual 1RM was small between trials ranging from -5.6 to 4.8% compared with the most accurate predictive method up to 90% of 1RM, which was more variable (-5.5 to 27.8%). Importantly, the V1RM (0.24 ± 0.06 m·s) was unreliable between trials (ICC = 0.42; SEM = 0.05 m·s; CV = 22.5%; ES = 0.14). The load-velocity relationship for the full depth free-weight back squat showed moderate reliability and validity but could not accurately predict 1RM, which was stable between trials. Thus, the load-velocity relationship 1RM prediction method used in this study cannot accurately modify sessional training loads because of large V1RM variability.

Identifying the Physical Fitness, Anthropometric and Athletic Movement Qualities Discriminant of Developmental Level in Elite Junior Australian Football: Implications for the Development of Talent.

Gaudion, SL, Doma, K, Sinclair, W, Banyard, HG, and Woods, CT. Identifying the physical fitness, anthropometric and athletic movement qualities discriminant of developmental level in elite junior Australian football: implications for the development of talent. J Strength Cond Res 31(7): 1830-1839, 2017-This study aimed to identify the physical fitness, anthropometric and athletic movement qualities discriminant of developmental level in elite junior Australian football (AF). From a total of 77 players, 2 groups were defined according to their developmental level; under 16 (U16) (n = 40, 15.6 to 15.9 years), and U18 (n = 37, 17.1 to 17.9 years). Players performed a test battery consisting of 7 physical fitness assessments, 2 anthropometric measurements, and a fundamental athletic movement assessment. A multivariate analysis of variance tested the main effect of developmental level (2 levels: U16 and U18) on the assessment criterions, whilst binary logistic regression models and receiver operating characteristic (ROC) curves were built to identify the qualities most discriminant of developmental level. A significant effect of developmental level was evident on 9 of the assessments (d = 0.27-0.88; p ≤ 0.05). However, it was a combination of body mass, dynamic vertical jump height (nondominant leg), repeat sprint time, and the score on the 20-m multistage fitness test that provided the greatest association with developmental level (Akaike's information criterion = 80.84). The ROC curve was maximized with a combined score of 180.7, successfully discriminating 89 and 60% of the U18 and U16 players, respectively (area under the curve = 79.3%). These results indicate that there are distinctive physical fitness and anthropometric qualities discriminant of developmental level within the junior AF talent pathway. Coaches should consider these differences when designing training interventions at the U16 level to assist with the development of prospective U18 AF players.

Discriminating Talent Identified Junior Australian Footballers Using a Fundamental Gross Athletic Movement Assessment.

Talent identification (TID) is a pertinent component of the sports sciences, affording practitioners the opportunity to target developmental interventions to a select few; optimising financial investments. However, TID is multi-componential, requiring the recognition of immediate and prospective performance. The measurement of athletic movement skill may afford practitioners insight into the latter component given its augmented relationship with functional sport specific qualities. It is currently unknown whether athletic movement skill is a discriminant quality in junior Australian football (AF). This study aimed to discriminate talent identified junior AF players from their non-talent identified counterparts using a fundamental gross athletic movement assessment. From a total of 50 under 18 (U18) AF players; two groups were classified a priori based on selection level; talent identified (n = 25; state academy representatives) and non-talent identified (n = 25; state-based competition representatives). Players performed a fundamental gross athletic movement assessment based on the Athletic Ability Assessment (AAA), consisting of an overhead squat, double lunge (left and right legs), single leg Romanian deadlift (left and right legs), and a push up (six movement criterions). Movements were scored across three assessment points using a three-point scale (resulting in a possible score of nine for each movement). A multivariate analysis of variance revealed significant between group effects on four of the six movement criterions (d = 0.56 - 0.87; p = 0.01 - 0.02). Binary logistic regression models and a receiver operating characteristic curve inspection revealed that the overhead squat score provided the greatest group discrimination (ß(SE) = -0.89(0.44); p < 0.05), with a score of 4.5 classifying 64% and 88% of the talent identified and non-talent identified groups, respectively. Results support the integration of this assessment into contemporary talent identification approaches in junior AF, as it may provide coaches with insight into a juniors developmental potential.

Sprint acceleration characteristics across the Australian football participation pathway.

The aim of this study was to compare the force, velocity and power profiles of a maximal sprint acceleration through different competition levels of the Australian Football (AF) participation pathway. One hundred and sixty-two junior AF athletes across five competition levels including State under 18's (ST 18), State under 16's (ST 16), local under 18's (LOC 18), local under 15's (LOC 15), and local under 14's (LOC 14) participated in this cross-sectional study. Velocity-time data from maximal sprint accelerations were analysed to derive athlete's sprint acceleration characteristics and split times. ST 18 showed a more force-orientated profile than the LOC 18 with moderate differences in relative theoretical maximal force (F0) (7.54%), absolute F0 (10.51%), and slope of the force-velocity relationship (Sf-v) (9.27%). Similarly, small differences were found between ST 18 and ST 16 in relative F0 (4.79%) and Sf-v (6.28%). Moderate to extremely large differences were observed between players competing in older (ST 18, LOC 18, ST 16) compared to younger (LOC 15, LOC 14) competition levels highlighting the potential influence of biological maturation. It is recommended that practitioners working with junior AF players to consider developing a force-orientated sprint acceleration profile to improve sprinting performance.

The perceptions of mental health clinicians integrating exercise as an adjunct to routine treatment of depression and anxiety.

Individuals with depressive symptoms often experience changes in physical activity and lifestyle factors. Despite the benefits of exercise, mental health clinicians often do not refer for or prescribe exercise as part of traditionally accepted models of care for consumers with depression and anxiety. The aims were to investigate: (i) mental health clinicians' understanding of the relationship between exercise and mental health, (ii) if and how exercise is used by mental health clinicians in treatment for depression and anxiety, and (iii) the barriers to prescription of exercise. A descriptive qualitative method was used, and data were collected via individual semi-structured interviews. Ten mental health clinicians with varying backgrounds participated in this study. The data driven inductive analysis of participants views identified three themes: (i) knowing and not knowing, (ii) consumer comorbidities - the risk and benefit dilemma, and (iii) protecting vulnerable consumers. Enhancing clinicians' knowledge of the beneficial role of exercise in treatment for consumers' experiencing depression and anxiety is an important step. Mental health services can support integration of exercise by implementing policies and training for staff to support exercise prescription, and the role and referral of exercise and physical activity specialists, as part of routine care to improve clinical outcomes for consumers. Additional considerations should be given to fiscal support to access exercise as an adjunct therapy.

Poor Reporting of Exercise Interventions for Hamstring Strain Injury Rehabilitation: A Scoping Review of Reporting Quality and Content in Contemporary Applied Research.

OBJECTIVE: To review the quality of reporting and identify the content of exercise interventions prescribed for hamstring strain injury (HSI) rehabilitation in the scientific literature from 2010 to 2020. DESIGN: Scoping review. LITERATURE SEARCH: We searched the bibliometric databases Web of Science, CINAHL, SPORTDiscus, Scopus, Cochrane Library, MEDLINE, and Embase. STUDY SELECTION CRITERIA: Original research articles (randomized controlled trials and cohort studies) published from 2010 to 2020 that described an exercise rehabilitation intervention for participants with acute HSIs were included. Injuries must have been confirmed within 7 days of occurrence via clinical assessment and/or diagnostic imaging. DATA SYNTHESIS: The quality of reporting, in terms of completeness of exercise intervention description, was evaluated using the Consensus on Exercise Reporting Template (CERT), and the content of interventions was categorized into exercise types. RESULTS: Fourteen studies were included; exercise intervention quality of reporting was moderate in 3 studies and low in 11 studies. Using the 19-item CERT, an average of 8.8 items (range, 4-14) were reported across all studies. Two studies reported sufficient exercise content and progression information to allow replication. Exercises categorized as hamstring flexibility, hamstring strength, running related, and non-hamstring specific were prescribed in 13, 11, 10, and 10 studies, respectively. Half of the included studies incorporated all 4 exercise types in their exercise interventions. CONCLUSION: There is a wide variety of exercise interventions applied in published research that has addressed HSI rehabilitation. Researchers must improve reporting quality to support other professionals in replicating exercise interventions and help practitioners to effectively implement research in practice. J Orthop Sports Phys Ther 2022;52(3):130-141. Epub 21 Sep 2021. doi:10.2519/jospt.2022.10641.