Search

Step‐up variations are frequently used in sports performance to develop coordinated and powerful movements that transfer to running. This study aimed to quantify the kinetic characteristics of the first foot contact of four different step‐up variations. Ten professional rugby league players participated in this study and performed the Barbell One Box Step‐Up with Catch (BB1), Barbell Two Box Step‐Up (BB2), Vest Two Box Run (VEST) and Step‐Up Jump (JUMP) as part of routine in‐season strength training sessions during one season. Peak force, total impulse and maximal rate of force development (RFD) were measured from first foot contact on the step‐up box. Significantly greater peak force and RFD were observed in JUMP than any other variation (standardized mean difference; SMD: 3.9–5.5; p < 0.001). Total impulse was equal between JUMP and BB1, and significantly greater in JUMP than BB2 and VEST (SMD: 1.3–2.3; p < 0.001), and in BB1 than BB2 and VEST (SMD: 1.8–2.8; p < 0.001). Significantly larger peak force and RFD were observed in BB2 and VEST than BB1 (SMD: 0.6–0.7) and in total impulse in BB2 than VEST (SMD: 1.6) (p < 0.05). The results of this study highlight that step‐up exercise variations maximize different kinetic characteristics, which may transfer differently to athlete running performance. Highlights: The Step‐Up Jump variation was shown to produce the largest relative peak force, largest rate of force development (RFD) and equal largest total impulse and therefore may have the greatest transferability to maximal speed running through the maximization of the stance phase.The Barbell Two Box Step‐Up (BB2) and Vest Two Box Run (VEST), produced significantly greater peak relative force and RFD than the Barbell One Box Step‐Up with Catch (BB1) and therefore may have better transferability to acceleration ability.Coaches can use the findings of this study to assist their selection of step‐up variations that are best suited to develop running ability and should consider the testing results and individual requirements of each athlete. [ABSTRACT FROM AUTHOR]

Wade, JA, Fuller, JT, Devlin, PJ, and Doyle, TLA. Senior and junior rugby league players improve lower-body strength and power differently during a rugby league season. J Strength Cond Res 36(5): 1367–1372, 2022—This investigation evaluated lower-body strength and power changes across a rugby league season in elite junior and senior athletes. Twenty-five senior and 20 junior rugby league players performed an isometric midthigh pull and countermovement jump at 3 time points in a National Rugby League training season (mid-preseason, end-preseason, and in-season). Linear fixed-effects models were used to compare isometric midthigh pull force and countermovement jump power between player experience groups (senior vs. junior) across the season phases (mid-preseason vs. end-preseason vs. and in-season). Cohen's effect sizes (ES) with 95% confidence intervals were calculated for pairwise comparisons. For senior players, absolute and relative strength (ES = 0.38, p < 0.007) and power (ES = 0.64, p < 0.008) increases were observed at end-preseason compared with mid-preseason, but there were no changes in-season (ES = 0.02, p > 0.571). For junior players, strength did not change (ES < 0.01, p > 0.738) and absolute power decreased (ES = 0.29, p < 0.014) at end-preseason compared with mid-preseason; large increases were evident for absolute and relative strength (ES = 1.43, p < 0.001) and power (ES = 0.62, p < 0.001) in-season. This research demonstrates senior and junior rugby league players exhibit unique patterns of improvements in lower-body strength and power across different phases of the season. This highlights the importance for training programs to differ between junior and senior athletes and target different physical qualities for both groups at different times of the season, thus providing guidance for strength and conditioning coaches. [ABSTRACT FROM AUTHOR]

Johnston, RD, Thornton, HR, Wade, JA, Devlin, P, and Duthie, GM. The distribution of match activities relative to the maximal mean intensities in professional rugby league and Australian football. J Strength Cond Res 36(5): 1360–1366, 2022—This study determined the distribution of distance, impulse, and accelerometer load accumulated at intensities relative to the maximal mean 1-minute peak intensity within professional rugby league and Australian football. Within 26 rugby league (n = 24 athletes) and 18 Australian football (n = 38 athletes) games, athletes wore global navigation satellite system devices (n = 608 match files). One-minute maximal mean values were calculated for each athlete per game for speed (m·minP−1P), accelerometer load (AU·minP−1P), and acceleration (m·sP−2P). Volumes for each parameter were calculated by multiplying by time, specifying total distance, accelerometer load, and impulse. The distribution of intensity of which these variables were performed relative to the maximal mean was calculated, with percentages ranging from 0–110%, separated into 10% thresholds. Linear mixed models determined whether the distribution of activities within each threshold varied, and positional differences. Effects were described using standardized effect sizes (ESs), and magnitude-based decisions. Across both sports, the distribution of activity (%) largely reduced the closer to the maximal mean 1-minute peak and was highest at ∼60% of the maximal mean peak. When compared with Australian football, a higher percentage of total distance was accumulated at higher intensities (70–80% and 100–110%) for rugby league (ES range = 0.82–0.87), with similar, yet larger differences for accelerometer load >80% (0.78–1.07) and impulse >60% (1.00–2.26). These findings provide information of the volume of activities performed relative to the mean maximal 1-minute peak period, which may assist in the prescription of training. [ABSTRACT FROM AUTHOR]

This investigation determined differences in lower body strength and power between elite junior (17-20 years) and elite senior (open-aged) rugby league athletes. Twenty junior and 25 senior athletes performed an isometric mid-thigh pull, countermovement jump, repeated jump, and broad jump tests during a National Rugby League pre-season. The effects of age (junior vs. senior) and position (adjustables vs. hit-up forwards vs. outside backs) on test results were investigated using a two-way analysis of variance. Cohen’s d effect sizes (ES) and 95% confidence intervals were calculated for pairwise comparisons. Isometric mid-thigh pull absolute peak force was greater for senior players compared to junior players (ES=0.88, p<.05). Countermovement jump absolute peak power was greater for outside backs (ES=1.12) and hit-up forwards (ES=1.23) compared to adjustables (p<.05), greater for senior outside backs compared to junior outside backs (ES=1.53, p<.05), and greater for junior hit-up forwards compared to senior hit-up forwards (ES=1.00, p<.05). This research demonstrated the differences in strength and power of rugby league athletes between playing age and position. Improving lower body strength should be prioritised for athletic development of junior rugby league athletes, with consideration given to requirements across different playing positions. [ABSTRACT FROM AUTHOR]

Previous research has quantified the peak movement demands of elite rugby league match-play, but the peak accelerometer load or the semi-professional peak demands remain unknown. The aim of this research was to determine the peak movement demands of professional and semi-professional rugby league competition. Wearable microtechnology devices tracked the physical activity profiles of players during 26 professional (n = 351 files) and 22 semi-professional (n = 267 files) matches. Following each match, data were exported in raw form to extract the peak 1- to 10-min periods for speed, average acceleration, and accelerometer load of each player, using a rolling average method. To determine the difference between playing levels (professional vs. semi-professional) and position (forwards vs. backs), linear mixed models were used. The intercept and the slope were calculated based on the power law relationship to provide the peak, and rate of decay, of each dependent variable. Cohen's effect size (ES) statistic was used to determine the magnitude of differences between positions and playing level. There was little difference between playing standards, with only small differences in running speed, with a greater intercept and slope for the professional forwards compared with semi-professional forwards (intercept ES: 0.37; 90%CL: 0.19 to 0.55; slope ES: 0.35; 0.15 to 0.55). For positional comparisons (forwards vs. backs), there was no difference in running speeds at the professional level, but there was substantially greater running speed for backs compared to forwards in semi-professional competition, with small to moderate differences (ES range: 0.60–0.39). Both professional and semi-professional forwards showed small to moderately higher accelerometer load compared to backs, which increased with period duration (ES range: 0.22–0.79). Similarly, acceleration demands were greater for forwards compared to backs across both playing standards, with moderate to large differences (ES range: 0.52–0.96). Overall, the results of this study show that there is a small difference in the peak running speed for forwards in professional competition, but otherwise there are no meaningful differences in movement demands of professional and semi-professional rugby league match-play. Forwards display greater acceleration and accelerometer load across a number of rolling average durations compared to backs. [ABSTRACT FROM AUTHOR]

INTRODUCTION: Strength and conditioning coaches play an important role in developing the physical attributes required for sport while athletes are progressing through the developmental years. Strength and power are important characteristics for performance in rugby league. The purpose of this study was to provide a lower body strength and power profile of elite junior (aged 17-20 years) and elite senior (open-aged professional) rugby league athletes within their respective player positions groups. In doing this, the research will provide practitioners with improved understanding of what physical attributes should be targeted in an appropriate athletic development program for 17-20 year old elite rugby league athletes. METHODS: Twenty junior aged elite RL players currently competing in the elite junior National Youth Competition and 25 senior aged rugby league players currently competing in the elite professional National Rugby League competition were recruited. Participants were split into 3 player groups; Adjustables (ADJ), Hit-Up Forwards (HUF) and Outside Backs (OB), as determined by their dominant playing position during matches. The testing protocol was conducted during preseason consisting of counter-movement jump, repeated jump, broad jump, and isometric mid-thigh pull. The effects of player group (senior vs junior) and position (ADJ vs HUF vs OB) on lower body strength, power, and jump results were investigated using a two-way analysis of variance. Statistical significance was set at an alpha level of 0.05. Where significant interactions or main effects were found, post hoc pairwise comparisons were made using the least significant difference method. Cohen's d effect sizes (ES) were calculated for pairwise comparisons. RESULTS: OB (5781N ± 615N, ES=1.26) and HUF (5862N ± 747N, ES=1.26) players showed greater absolute lower body power during the counter-movement jump than ADJ (4985N ± 642N, p < 0.05). Junior HUF (6271N ± 932N) showed greater absolute lower body power than senior HUF (5590N ± 456N, p < 0.05, ES=0.92). Senior OB (6184N ± 571N) showed greater absolute lower body power than junior OB (5429N ± 417N, p < 0.05, ES=1.51). There were no significant interactions for reactive strength index in the repeat effort jump test. HUF players (288cm ± 17cm, ES=1.03) and OB players (288cm ± 16cm, ES=1.01) showed greater distance in the broad jump test than ADJ (272cm ± 16cm, p < 0.05). Senior players (3883N ± 675N) showed greater absolute lower body peak force in the IMTP than junior players (3329N ± 410N, p < 0.05, ES=0.90). HUF (3913N ± 656N) players showed greater absolute lower body peak force than ADJ (3159N ± 369N, p < 0.05, ES=1.39). Senior HUF (4127N ± 759N, ES=0.95) and senior OB (3801N ± 400N, ES=1.36) showed greater absolute lower body peak force than junior HUF (3591N ± 25N, p < 0.05) and junior OB (3244N ± 419N, p < 0.05) respectively. DISCUSSION: In the current research, senior players showed significantly greater maximum force production during the isometric midthigh pull test than junior players across all playing positions. Senior OB demonstrated greater lower body power than junior OB in the counter-movement jump. These findings are consistent with elite rugby league match data, which indicate maximal power production an important part of the game for OB players, due to the sprint running demands. In contrast to the OB position, junior age HUF showed greater lower body power than senior HUF during the countermovement jump test. The increased wrestling demands require HUF to have greater upper body strength and body mass to enhance this technical element of the game. In summary, this research has shown differences in the strength and power profile of rugby league athletes across senior and junior players and different playing positions. These results provide important guidelines for practitioners involved in developing training programs for elite junior aged athletes preparing for elite senior rugby league. PRACTICAL APPLICATION: • Improving lower body strength should be the main priority for any athletic development program aimed at developing junior rugby league athletes into senior elite rugby league athletes. • Consideration must be given to the requirements of different playing positions when focusing on other physical qualities within a development program • When focusing on upper body strength and mass for improved tackling and wrestling in rugby league in hit-up forwards, ensure lower body power production is also being addressed. [ABSTRACT FROM AUTHOR]

Introduction: Rugby league is a physically demanding sport that necessitates considerable nutritional intake, focusing on quality and type, in order to optimize training and competition demands. However, rugby league athletes are reported to have inadequate nutrition intake to match these demands. Some factors that may determine an athlete's nutrition intake have been reported in other sports, including (but not limited to, knowledge, time, cooking skills, food costs, income, belief in the importance of nutrition, body composition goals, and family/cultural support). However, these potential factors are relatively unexplored in rugby league, where a range of personal (age, body composition) or social (ancestry) influences could affect nutritional intake. Further exploration of these factors is warranted to understand the knowledge, attitudes and behavior underlying rugby league athletes' nutritional intake that can provide practitioners with a more detailed understanding of how to approach nutrition behaviors and attitudes in rugby league athletes., Objectives: The primary aim was to describe the nutrition behaviors and knowledge of rugby league athletes. A secondary aim was to compare nutrition knowledge and behavior based on age, body composition and self-identified ancestry., Methods: Fifty professional rugby league athletes anonymously completed a seventy-six-question online survey. The survey consisted of three sections : 1) sports nutrition knowledge, 2) attitudes toward nutrition on performance , and 3) nutrition behaviors. All participants completed the online survey without assistance using their own personal device, with data entered via REDCap during pre-season. Nutrition knowledge was compared based on age (years), body composition (body fat percentage (%)) and ancestral groups (Pasifika, Aboriginal and/or Torres Strait Islander (ATSI) and Anglo- European).Pearson correlation was used for the relationship between nutrition knowledge, age and body composition. An Analysis of Covariance (ANCOVA) was used to determine nutrition knowledge differences between ancestral groups with age and body composition as covariates. Attitudes and behaviors were compared based on age groups (<20, 20-24 and >25 y), ancestry and body composition. Attitudes and behaviors were analyzed by Pearson correlation for body composition, one-way ANOVA for age groups and ANCOVA for ancestry with covariates age and body composition., Results: Overall athletes' nutrition knowledge score was reported as 40 ± 12% (overall rating "poor"). Nutritional behaviors were significant for body composition, as those with lower body fat percentage had higher intakes of vegetables and dairy products ( p  = 0.046, p  = 0.009), and ate more in the afternoon (lunch p  = 0.048, afternoon snack p  = 0.036). For ancestry, after adjustment for both age and body composition, Pasifika athletes were more inclined to miss breakfast and lunch compared to their Anglo-European ( p  = 0.037, p  = 0.012) and ATSI ( p  = 0.022, p  = 0.006) counterparts and ate more fruit than Anglo-Europeans ( p  = 0.006, p  = 0.016). After adjustment for body composition, ATSI athletes also viewed the impact of nutrition on mental health and well-being significantly lower than Pasifika ( p  = 0.044)., Conclusion: These findings suggest differences exist within rugby league athletes based on ancestral backgrounds and body composition for nutrition attitudes, behaviors and knowledge. Such outcomes could be used when designing nutrition education interventions, with consideration given to these factors to optimize long-term positive behavior change.