Search Results

You are looking at 1 - 7 of 7 items for

  • Author: Rhonda Orr x
Clear All Modify Search
Restricted access

Cloe Cummins and Rhonda Orr

Objective:

To investigate the impact forces of collision events during both attack and defense in elite rugby league match play and to compare the collision profiles between playing positions.

Participants:

26 elite rugby league players.

Methods:

Player collisions were recorded using an integrated accelerometer in global positioning system units (SPI-Pro X, GPSports). Impact forces of collisions in attack (hit-ups) and defense (tackles) were analyzed from 359 files from outside backs (n = 78), adjustables (n = 97), wide-running forwards (n = 136), and hit-up forwards (n = 48) over 1 National Rugby League season.

Results:

Hit-up forwards were involved in 0.8 collisions/min, significantly more than all other positional groups (wide-running forwards P = .050, adjustables P = .042, and outside backs P = .000). Outside backs experienced 25% fewer collisions per minute than hit-up forwards. Hit-up forwards experienced a collision within the 2 highest classifications of force (≥10 g) every 2.5 min of match play compared with 1 every 5 and 9 min for adjustables and outside backs, respectively. Hit-up forwards performed 0.5 tackles per minute of match play, 5 times that of outside backs (ES = 1.90; 95% CI [0.26,3.16]), and 0.2 hit-ups per minute of match play, twice as many as adjustables.

Conclusions:

During a rugby league match, players are exposed to a significant number of collision events. Positional differences exist, with hit-up and wide-running forwards experiencing greater collision events than adjustables and outside backs. Although these results may be unique to the individual team’s defensive- and attacking-play strategies, they are indicative of the significant collision profiles in professional rugby league.

Restricted access

Mark Booth, Rhonda Orr and Stephen Cobley

Purpose: To conduct a systematic review into the effect of training load (TL) on both performance measures and injury characteristics in rugby league players. Methods: Based on PRISMA guidelines, a systematic search of electronic databases was performed from the earliest record to December 2016. Five electronic databases (MEDLINE, SPORTDiscus, CINAHL, Web of Science, and AusSportMed) were searched using keywords within the subcategories of population (rugby league players), intervention (training quantification), and outcomes (performance or injury). Original peer-reviewed published manuscripts were considered if they had a clear quantification of TL (eg, session rating of perceived exertion), clear measures of performance (tests of physiological parameters relative to rugby league players [eg, agility]), and/or injury characteristics (eg, injury incidence). Results: Twelve studies met the inclusion criteria. The highest TL was observed in preseason training phases. Higher TL elicited greater improvements in maximal aerobic power, vertical jump (in cm), and agility scores (in s). Higher TL was associated with higher incidence of muscular strains and joint sprains, lower-limb injuries, and overexertion and overuse injuries. Conclusions: Findings suggest a dose–response relationship between TL, physical performance, and injury characteristics. However, due to study and methodological limitations, the precise nature of this relationship is, as yet, inconclusive. Therefore, the development of uniform TL definition and quantification and further research is warranted.

Restricted access

Joanne Hausler, Mark Halaki and Rhonda Orr

Purpose:

To investigate activity profiles of Australian rugby league players during match play by competition, position, and match outcome in the New South Wales (NSW) second-tier competitions.

Methods:

Eighteen NSW Cup (NSWC) and 22 National Youth Competition (NYC) players, participating in this prospective cohort study, were categorized into 3 positional groups: forwards, adjustables, and outside backs. Global positioning system devices were used to examine activity profiles (distance and relative distance covered in walking, jogging, moderate, high, very high, and sprinting speed zones and quantification of high-speed movement) during match play in 21 NSWC and 22 NYC matches (N = 339 files).

Results:

NSWC players performed more sprints (36.5 ± 9.3 vs 28.4 ± 9.2) and greater relative distance in moderate speed zones (18.4 ± 3.2 vs 15.8 ± 3.1 m/min) than NYC. NSWC outside backs covered greater relative distance in jogging (29.4 ± 2.9 vs 24.8 ± 2.7 m/min) and moderate speed zones (17.0 ± 2.6 vs 12.8 ± 2.8 m/min) than their NYC counterparts. Adjustables performed more sprints (39.4 ± 10.1 vs 27.0 ± 9.2), high-intensity accelerations (3.7 ± 1.4 vs 1.9 ± 1.4), and relative distance (84.8 ± 4.3 vs 88.6 ± 4.8 m/min) than forwards and greater relative distance (81.5 ± 3.8 m/min) and sprints (31.0 ± 8.0) than outside backs. Adjustables recorded greater relative distance (19.8 m/min) in moderate speed zones than forwards (16.7 ± 3.1 m/min) and outside backs (14.9 ± 2.7 m/min). Adjustables covered ~685 m more than outside backs during a win.

Conclusions:

This is the first study to document the activity profiles of the NSW second-tier rugby league competition. The findings underscore the elevated match demands of adjustables and indicate higher intensity of play in NSWC than NYC that may more closely resemble the demands of National Rugby League match play.

Restricted access

Shane Ball, Mark Halaki, Tristan Sharp and Rhonda Orr

Context: Rugby union is a physically demanding collision sport with high injury rates. There is a common perception that higher training loads result in greater injury risk in field-based sports. Objectives: To determine injury, anthropometric, and physical-performance characteristics in junior rugby union players and investigate the interaction between training load and injury across a competitive season. Design: Prospective cohort study. Methods: Fifty-one players (age 19.2 ± 0.7 y) from an under-20 university rugby union team (forwards, n = 27; backs, n = 24) participated in a study conducted over a competition season. Training load, injury characteristics, anthropometry, physiological performance, and match time-loss injury incidence were observed. Results: Backs had significantly lower body mass (ES [95% CI] = 1.6 [0.9, 2.2]), skinfold thickness (ES = 1.1 [0.5, 1.7]), strength (squat ES = 0.6 [0.0, 1.2], deadlift ES = 0.6 [0.0, 1.1], bench press ES = 0.9 [0.4, 1.5]), lower-body power (ES = 0.4 [−0.2, 1.0]), and higher maximal aerobic capacity (ES = −0.3 [−0.8, 0.3]) than forwards. Match injury incidence was 107.3 injuries/1000 player hours (forwards 91.4/1000, backs 125.5/1000) during preseason and 110.7 injuries/1000 player hours (forwards 124.1/1000, backs 95.2/1000) during in-season. Forwards showed higher incidence of joint and ligament (P = .049) and upper-limb (P = .011) injuries than backs. No significant relationship between overall training load and match injury incidence was found. However, lower match injury incidence was associated with higher weekly training volume in backs (P = .007). Conclusions: Positional differences in body composition, performance, injury characteristics, and match injury patterns were identified in junior university rugby union players, indicating the need for position-specific training programs to reduce risk of injury.

Restricted access

Melanie Vetter, Helen O’Connor, Nicholas O’Dwyer and Rhonda Orr

Background: Physically active learning that combines physical activity with core curriculum areas is emerging in school-based health interventions. This study investigates the effectiveness of learning an important numeracy skill of times tables (TT) while concurrently engaging in aerobic activity compared with a seated classroom approach. Methods: Grade-4 primary school students were randomly allocated to physical activity (P) or classroom (C) groups and received the alternate condition in the following term. P group received moderate to vigorous exercise (20 min, 3 times per week, 6 wk) while simultaneously learning selected TT. C group received similar learning, but seated. Changes in TT accuracy, general numeracy, aerobic fitness, and body mass index were assessed. Data were expressed as mean (SEM) and between-condition effect size (ES; 95% confidence interval). Results: Participants [N = 85; 55% male, 9.8 (0.3) y, 36.4% overweight/obese] improved similarly on TT in both conditions [C group: 2.2% (1.1%); P group: 2.5% (1.3%); ES = 0.03; −0.30 to 0.36; P = .86]. Improvement in general numeracy was significantly greater for P group than C group [C group: 0.7% (1.2%); P group: 5.3% (1.4%); ES = 0.42; 0.08 to 0.75; P < .03]. An improvement in aerobic fitness for P group (P < .01) was not significantly greater than C group [C group: 0.8 (0.6); P group: 2.2 (0.5) mL·kg·min−1; ES = 0.32; −0.01 to 0.66; P = .06]. Body mass index was unchanged. Conclusion: Combined movement with learning TT was effective. Physically active learning paradigms may contribute to meeting daily physical activity guidelines while supporting or even boosting learning.

Restricted access

Cloe Cummins, Blake McLean, Mark Halaki and Rhonda Orr

Purpose:

To quantify the external training loads of positional groups in preseason training drills.

Methods:

Thirty-three elite rugby league players were categorized into 1 of 4 positional groups: outside backs (n = 9), adjustables (n = 9), wide-running forwards (n = 9), and hit-up forwards (n = 6). Data for 8 preseason weeks were collected using microtechnology devices. Training drills were classified based on drill focus: speed and agility, conditioning, and generic and positional skills.

Results:

Total, high-speed, and very-high-speed distance decreased across the preseason in speed and agility (moderate, small, and small, respectively), conditioning (large, large, and small) and generic skills (large, large, and large). The duration of speed and generic skills also decreased (77% and 48%, respectively). This was matched by a concomitant increase in total distance (small), high-speed running (small), very-high-speed running (moderate), and 2-dimensional (2D) BodyLoad (small) demands in positional skills. In positional skills, hit-up forwards (1240 ± 386 m) completed less very-high-speed running than outside backs (2570 ± 1331 m) and adjustables (2121 ± 1163 m). Hit-up forwards (674 ± 253 AU) experienced greater 2D BodyLoad demands than outside backs (432 ± 230 AU, P = .034). In positional drills, hit-up forwards experienced greater relative 2D BodyLoad demands than outside backs (P = .015). Conversely, outside backs experienced greater relative high- (P = .007) and very-high-speed-running (P < .001) demands than hit-up forwards.

Conclusion:

Significant differences were observed in training loads between positional groups during positional skills but not in speed and agility, conditioning, and generic skills. This work also highlights the importance of different external-load parameters to adequately quantify workload across different positional groups.

Restricted access

Nathan J. de Vos, Nalin A. Singh, Dale A. Ross, Theodora M. Stavrinos, Rhonda Orr and Maria A. Fiatarone Singh

Objective:

To determine the effect of training intensity on the contributions of force and velocity to improvements in peak power (PP) after explosive resistance training in older adults.

Methods:

112 healthy older adults (69 ± 6 yr) were randomized to explosive resistance training at 20% (G20), 50% (G50), or 80% (G80) maximal strength (1-repetition maximum) for 8–12 wk (twice weekly, 5 exercises, 3 sets of 8 explosive concentric/slow eccentric repetitions) using pneumatic resistance machines or a nontraining control group (CON).

Results:

Force at peak power (FPP) increased significantly and similarly among training groups compared with CON. Velocity at peak power (VPP) did not improve significantly and remained similar between all groups. Force contributed significantly more to PP production in G80 and G50 than in CON. The change in PP was independently predicted by changes in fat-free mass in G80 and by changes in both FPP and VPP in G50 and G20.

Conclusion:

Explosive resistance training in older adults results in the ability to produce higher PP outputs with heavier loads without loss of movement velocity. Moderate- to high-intensity training induced a greater relative contribution of force to PP production in this cohort.