Positional group significantly influences the offensive and defensive skill involvements of junior representative rugby league players during match play

© 2015 Taylor & Francis. This study examined the skill involvements of three positional groups across a junior representative rugby league season. Data were collected from 45 rugby league players (mean ± SD; age = 16.5 ± 1.0 years) currently participating in the Harold Matthews and SG Ball Cup. Players were subdivided into hit-up forwards, adjustables and outside backs. The frequency (n · min−1) of offensive, defensive and overall involvements was coded for each group using a notation system and a practical coach skill analysis tool. Multivariate analysis of variance (MANOVA) revealed a significant effect of playing position on skill involvements (F = 9.06; P < 0.001; ES = 0.41). Hit-up forwards performed a significantly greater frequency of offensive (0.31 ± 0.10), defensive (0.42 ± 0.15) and overall involvements (0.74 ± 0.19) when compared to adjustables (0.20 ± 0.08, 0.28 ± 0.08 and 0.52 ± 0.15, respectively) and outside backs (0.20 ± 0.12, 0.11 ± 0.07 and ± 0.31 ± 0.17, respectively). Further, adjustables performed a significantly greater number of defensive (0.28 ± 0.08) and overall involvements (0.52 ± 0.15) when compared to outside backs (0.11 ± 0.07 and 0.31 ± 0.17, respectively). The findings of this study suggest that it is important to consider a junior player’s positional group when analysing their skill involvements. Information gained from this study could assist in the design of specific training methodologies for junior rugby league players in high-level talent development programmes

The role of anthropometric, performance and psychological attributes in predicting selection into an elite development programme in older adolescent rugby league players

© 2016 Informa UK Limited, trading as Taylor & Francis Group. This study aimed to identify attributes that discriminate selected from non-selected players and predict selection into a rugby league development programme in older adolescent players. Anthropometric, performance and psychological attributes were measured in under-16 (N = 100) and under-18 (N = 60) rugby league players trialling for selection into a development programme with a professional Australian club. Sprint times (P  <  0.001), predicted VO 2max (P = 0.002) and push-ups 1   min (P = 0.004) were superior in selected under-16 players, and sprint times (P ≤ 0.045), push-ups 1   min (P  <  0.001) and chin-ups 1   min (P = 0.013) were superior in selected under-18 players. Further, 10-m sprint (β = −7.706, standard error [SE] = 2.412), VO 2max (β = 0.168, SE = 0.052) and body mass (β = 0.071, SE = 0.023) significantly predicted selection (R 2  = 0.339) in under-16 players, while push-ups 1   min (β = 0.564, SE = 0.250), 10-m sprint (β = −68.477, SE = 28.107), body mass (β = 0.360, SE = 0.155) and chronological age (β = −3.577, SE = 1.720) significantly predicted selection (R 2  = 0.894) in under-18 players. These findings emphasise the importance of performance attributes in junior rugby league and indicate talent identification test batteries should be age-specific in older adolescent players

Temporal associations between individual changes in hormones, training motivation and physical performance in elite and non-elite trained men

To advance our understanding of the hormonal contribution to athletic performance, we examined the temporal associations between individual changes in testosterone (T) and/or cortisol (C) concentrations, training motivation and physical performance in elite and non-elite trained men. Two male cohorts classified as elites (n = 12) and non-elites (n = 12) completed five testing sessions over a six-week period. The athletes were tested for salivary T, C, T/C ratio, self-perceived training motivation, countermovement jump (CMJ) height and isometric mid-thigh pull peak force (IMTP PF), after which an actual training workout was performed. The elite men reported higher motivation to train and they produced greater CMJ height overall, whereas the non-elites had higher pooled T levels (p < 0.05). No significant group differences in C concentrations, T/C ratio or IMTP PF were found. The individual changes in T levels were positively associated with training motivation in the elite men only (p = 0.033), but the hormonal and motivation measures did not predict CMJ height or IMTP PF in either group. The monitoring of elite and non-elite men across a short training block revealed differences in T levels, motivation and lower-body power, which may reflect training and competitive factors in each group. Despite having lower T levels, the elite athletes showed better linkage between pre-training T fluctuations and subsequent motivation to train. The nature of the performance tests (i.e. single repetition trials) could partly explain the lack of an association with the hormonal and motivational measures

The role of anthropometric, performance and psychological attributes in predicting selection into an elite development programme in older adolescent rugby league players

© 2016 Informa UK Limited, trading as Taylor & Francis Group. This study aimed to identify attributes that discriminate selected from non-selected players and predict selection into a rugby league development programme in older adolescent players. Anthropometric, performance and psychological attributes were measured in under-16 (N = 100) and under-18 (N = 60) rugby league players trialling for selection into a development programme with a professional Australian club. Sprint times (P  <  0.001), predicted VO 2max (P = 0.002) and push-ups 1   min (P = 0.004) were superior in selected under-16 players, and sprint times (P ≤ 0.045), push-ups 1   min (P  <  0.001) and chin-ups 1   min (P = 0.013) were superior in selected under-18 players. Further, 10-m sprint (β = −7.706, standard error [SE] = 2.412), VO 2max (β = 0.168, SE = 0.052) and body mass (β = 0.071, SE = 0.023) significantly predicted selection (R 2  = 0.339) in under-16 players, while push-ups 1   min (β = 0.564, SE = 0.250), 10-m sprint (β = −68.477, SE = 28.107), body mass (β = 0.360, SE = 0.155) and chronological age (β = −3.577, SE = 1.720) significantly predicted selection (R 2  = 0.894) in under-18 players. These findings emphasise the importance of performance attributes in junior rugby league and indicate talent identification test batteries should be age-specific in older adolescent players

Reliability and Usefulness of the 30-15 Intermittent Fitness Test in Rugby League

This study examined the reliability and usefulness of the 30-15 Intermittent Fitness Test (30-15IFT) within rugby league. Fifty-five young rugby league players participated in the study. These included representative players from Under 16s (n = 19; 15.6 ± 0.3 years; 78.1 ± 10.9 kg), Under 18s (n = 21; 17.4 ± 0.5 years; 86.9 ± 11.2 kg), and Under 20s (n = 15; 19.4 ± 0.5 years; 95.9 ± 8.7 kg) squads within a professional rugby league club. Players performed the 30-15IFT twice within 9 days of each other. Maximal intermittent running velocity (VIFT) and heart rate at exhaustion (HRpeak) were collected for both tests. Intraclass correlation coefficients (ICCs) for the “Combined” and Under 20s were very large (r > 0.7), whereas the ICCs for Under 16s and Under 18s were almost perfect (r > 0.9). Coefficients of variation were 1.9% (95% confidence interval, 1.6–2.4) for the combined test-retest of the 30-15IFT and 0.6% (0.5–1.0) for HRpeak. As the typical error of measurement (TE) (0.36 km·h−1) was greater than the smallest worthwhile change (SWC) (0.21 km·h−1) value, the usefulness of the VIFT was rated as “marginal.” The TE for HRpeak was similar to the SWC, rating the usefulness of this variable as “OK.” Despite the usefulness of the 30-15IFT being deemed Marginal, a change as small as 0.5 km·h−1 (1 stage) in VIFT could be considered substantial or “real.” As a consequence, the 30-15IFT presents as both a reliable and useful field test in the assessment of intermittent fitness for rugby league players

Examining the skill involvements of under-16 rugby league players during a small-sided game and match-play

© The Author(s) 2016. This study investigated the correlations between the skill demands of an 'on-side' small-sided game (SSG) and match-play in under-16 junior rugby league players. Fifteen Harold Matthews players undertook a SSG (10 vs. 10 on a 68 m by 40 m playing surface for 3 min) in the week leading up to round 6 of their competitive season. The frequency of skill involvements (i.e. offensive, defensive and total) was manually coded using a specific criterion. The defensive and total skill involvements were significantly higher per minute of play in the SSG when compared to match-play. A significant, very large, positive correlation was observed between offensive and total skill involvements during a SSG and offensive skill involvements during a match (r(s) = 0.80, p < 0.01; r(s) = 0.71, p < 0.01, respectively). No significant correlations were evident for defensive skill involvements during SSG and match-play. Overall, it appears that the selected SSG provided players with ample opportunity to practice match-specific skills. In addition, the transfer of these opportunities seems confined to offensive rather then defensive skills

Running momentum: a new method to quantify prolonged high-intensity intermittent running performance in collision sports

Purpose: This study determined differences in prolonged high-intensity running (PHIR) performance and running momentum (pIFT) between competition levels and positional groups in rugby league. Methods: Elite Australian National Rugby League (NRL), sub-elite [state-based competition (SRL); National Youth Competition (NYC); local league (LL)] and junior-elite (U18; U16) rugby league players completed the 30–15 Intermittent Fitness Test (30–15IFT) to quantify PHIR performance. Final running momentum (pIFT; kg·m∙s−1) was calculated as the product of body mass and final running velocity (VIFT; m∙s−1). Effect sizes (ESs) were used to examine between-group differences. Results: 30–15IFT performance was possibly to likely higher in NRL players (19.5 ± 1.0 km·h−1; mean ± SD) when compared with SRL (ES = 0.6 ± 0.5; ES ± CI), NYC (ES = 0.6 ± 0.5) and U18 (ES = 0.8 ± 0.5) players. NRL players (537 ± 41 kg·m·s−1) possessed possibly to very likely greater pIFT than SRL (ES = 0.7 ± 0.5), NYC (ES = 1.2 ± 0.5), U18 (ES = 2.3 ± 0.6), U16 (ES = 3.0 ± 0.7) and LL players (ES = 2.0 ± 0.7). Middle forwards attained a likely superior pIFT (ES = 0.5 − 1.8) to all other positional groups. Conclusions: This study demonstrated that elite rugby league players possess superior PHIR capacities, whilst highlighting that pIFT can account for the disparities in body mass between groups

The Validity and Contributing Physiological Factors to 30-15 Intermittent Fitness Test Performance in Rugby League

Abstract: Scott, TJ, Duthie, GM, Delaney, JA, Sanctuary, CE, Ballard, DA, Hickmans, JA, and Dascombe, BJ. The validity and contributing physiological factors to 30-15 intermittent fitness test performance in rugby league. J Strength Cond Res 31(9): 2409-2416, 2017-This study examined the validity of the 30-15 Intermittent Fitness Test (30-15IFT) within rugby league. Sixty-three Australian elite and junior-elite rugby league players (22.5 +/- 4.5 years, 96.1 +/- 9.5 kg, [SIGMA]7 skinfolds: 71.0 +/- 18.7 mm) from a professional club participated in this study. Players were assessed for anthropometry (body mass, [SIGMA]7 skinfolds, lean mass index), prolonged high-intensity intermittent running (PHIR; measured by 30-15IFT), predicted aerobic capacity (MSFT) and power (AAS), speed (40 m sprint), repeated sprint, and change of direction (COD-505 agility test) ability before and after an 11-week preseason training period. Validity of the 30-15IFT was established using Pearson's coefficient correlations. Forward stepwise regression model identified the fewest variables that could predict individual final velocity (VIFT) and change within 30-15IFT performance. Significant correlations between VIFT and [SIGMA]7 skinfolds, repeated sprint decrement, V[Combining Dot Above]O2maxMSFT, and average aerobic speed were observed. A total of 71.8% of the adjusted variance in 30-15IFT performance was explained using a 4-step best fit model (V[Combining Dot Above]O2maxMSFT, 61.4%; average aerobic speed, 4.7%; maximal velocity, 4.1%; lean mass index, 1.6%). Across the training period, 25% of the variance was accounted by [DELTA]V[Combining Dot Above]O2maxMSFT (R2 = 0.25). These relationships suggest that the 30-15IFT is a valid test of PHIR within rugby league. Poor correlations were observed with measures of acceleration, speed, and COD. These findings demonstrate that although the 30-15IFT is a valid measure of PHIR, it also simultaneously examines various physiological capacities that differ between sporting cohorts

Examining the skill involvements of under-16 rugby league players during a small-sided game and match-play

This study investigated the correlations between the skill demands of an 'on-side' small-sided game (SSG) and match-play in under-16 junior rugby league players. Fifteen Harold Matthews players undertook a SSG (10 vs. 10 on a 68 m by 40 m playing surface for 3 min) in the week leading up to round 6 of their competitive season. The frequency of skill involvements (i.e. offensive, defensive and total) was manually coded using a specific criterion. The defensive and total skill involvements were significantly higher per minute of play in the SSG when compared to match-play. A significant, very large, positive correlation was observed between offensive and total skill involvements during a SSG and offensive skill involvements during a match (r(s)= 0.80, p < 0.01; r(s)= 0.71, p < 0.01, respectively). No significant correlations were evident for defensive skill involvements during SSG and match-play. Overall, it appears that the selected SSG provided players with ample opportunity to practice match-specific skills. In addition, the transfer of these opportunities seems confined to offensive rather then defensive skills. © The Author(s) 2016

Thigh-length compression stockings and DVT after stroke

Controversy exists as to whether neoadjuvant chemotherapy improves survival in patients with invasive bladder cancer, despite randomised controlled trials of more than 3000 patients. We undertook a systematic review and meta-analysis to assess the effect of such treatment on survival in patients with this disease