Predictors of Repeated High-Intensity-Effort Ability in Rugby League Players

2015 ◽  
Vol 10 (6) ◽  
pp. 718-724 ◽  
Author(s):  
Tim J. Gabbett ◽  
Aaron J. Wheeler

Purpose: To investigate the relationship between repeated high-intensity-effort (RHIE) ability and selected physical qualities in rugby league players. Methods: Sixteen rugby league players underwent measurements of upper-body strength (4-repetition-maximum [4RM] bench press, weighted chin-up, weighted dips), upper-body muscle endurance (body-mass maximum-repetition chin-up, body-mass maximum-repetition dips), lower-body strength (4RM squat), estimated maximal aerobic power (multistage fitness test), and RHIE ability. The RHIE-ability test consisted of 1 × 10-m sprint, 3 × full-contact 1-on-1 tackling efforts, and a 30-m jog recovery. Players performed 4 repetitions of the test, with each repetition completed in 40 second. During the RHIE test, player speed was evaluated with a 10-m sprint effort while the movement of players was recorded using a wearable microtechnology device. 2D Player Load was used to quantify the collision component of the test. Results: Speed decrement was lower for the first- (−2.4% ± 1.0%) than the second-grade (−4.7% ± 2.1%) players. Players with greater initial speed had a higher average speed over the 4 sprints (r = .75), while players with greater maximum-repetition dips maintained a higher 2D Player Load (r = .76). Conclusions: These findings demonstrate a relationship between well-developed acceleration and upper-body muscle-endurance qualities and RHIE ability in rugby league players. Training programs designed to develop acceleration and upper-body muscle endurance are likely to improve RHIE ability.

2019 ◽  
Vol 66 (1) ◽  
pp. 121-129 ◽  
Author(s):  
Marc Jon Booysen ◽  
Philippe Jean-Luc Gradidge ◽  
Demitri Constantinou

AbstractData regarding anthropometric and motor characteristics of elite national level female soccer players are scarce. Determining these characteristics may likely assist in evaluating the specificity of current training programmes, identify players who might lack specific qualities deemed critical for the successful execution of their tactical roles, and benchmark norms for developing future playing talent. Therefore, the aims of this study were to describe anthropometric and motor characteristics of South African national level female soccer players (n = 37) and determine possible differences with regard to their playing position. The following measurements and tests were performed: anthropometry (body mass index and sum-of-skinfolds), the countermovement jump, sprints (10 m, 20 m and 40 m), upper body muscle endurance (push-ups) and the Yo-Yo Intermittent Recovery Test - level 1. One-way analysis of variance revealed few differences in the main outcome variables. Fischer Least Significant Difference (LSD) showed that strikers had a greater body mass index than midfielders and defenders (both p = 0.04) and goalkeepers were heavier than defenders (p = 0.02). Goalkeepers were slower than strikers and defenders over 10 m (p = 0.01; p = 0.03) and 20 m (p = 0.001; p = 0.01). Midfielders were slower than strikers over 20 m (p = 0.02), and with strikers and defenders over 40 m (both p = 0.04). Defenders performed better than goalkeepers in the upper body muscle endurance test (p = 0.02). In conclusion, both strikers and defenders require speed to win ball possession, which may explain their fast sprint times. However, the similarity of certain motor characteristics across playing positions may suggest that conditioning coaches train players similarly, irrespective of their tactical position. The authors suggest that South African fitness professionals, particularly at a club level, develop physical conditioning programs specific to each field position. Furthermore, fitness assessments should occur on a continuous basis and comparisons should be made with existing normative data in order to guide the development of players over the course of their careers.


2020 ◽  
Vol 15 (4) ◽  
pp. 470-477 ◽  
Author(s):  
Jozo Grgic ◽  
Filip Sabol ◽  
Sandro Venier ◽  
Ivan Mikulic ◽  
Nenad Bratkovic ◽  
...  

Purpose: To explore the effects of 3 doses of caffeine on muscle strength and muscle endurance. Methods: Twenty-eight resistance-trained men completed the testing sessions under 5 conditions: no-placebo control, placebo control, and with caffeine doses of 2, 4, and 6 mg·kg−1. Muscle strength was assessed using the 1-repetition-maximum test; muscle endurance was assessed by having the participants perform a maximal number of repetitions with 60% 1-repetition maximum. Results: In comparison with both control conditions, only a caffeine dose of 2 mg·kg−1 enhanced lower-body strength (d = 0.13–0.15). In comparison with the no-placebo control condition, caffeine doses of 4 and 6 mg·kg−1 enhanced upper-body strength (d = 0.07–0.09) with a significant linear trend for the effectiveness of different doses of caffeine (P = .020). Compared with both control conditions, all 3 caffeine doses enhanced lower-body muscle endurance (d = 0.46–0.68). For upper-body muscle endurance, this study did not find significant effects of caffeine. Conclusions: This study revealed a linear trend between the dose of caffeine and its effects on upper-body strength. The study found no clear association between the dose of caffeine and the magnitude of its ergogenic effects on lower-body strength and muscle endurance. From a practical standpoint, the magnitude of caffeine’s effects on strength is of questionable relevance. A low dose of caffeine (2 mg·kg−1)—for an 80-kg individual, the dose of caffeine in 1–2 cups of coffee—may produce substantial improvements in lower-body muscle endurance with the magnitude of the effect being similar to that attained using higher doses of caffeine.


2006 ◽  
Vol 1 (4) ◽  
pp. 347-360 ◽  
Author(s):  
Daniel G. Baker ◽  
Robert U. Newton

Purpose:To examine the upper body strength, speed, power, and strength-endurance of rugby-league players of different ranks. These data could provide information pertinent to the importance of these factors for different grades of rugby league and for positional groups in those different grades.Methods:Sixty rugby-league players, 20 participants each in the elite, national first-division league (NRL), state-based second-division league (SRL), and intracity third-division league (CRL), served as subjects. Maximal upper body strength, power, speed, and muscle endurance were assessed using the bench-press exercise.Results:The NRL players were significantly stronger (141.4 ± 15.4 kg) than SRL (126.6 ± 13.1 kg, ES = 1.033) and CRL (108.1 kg ± 11.6, ES = 2.458) and more powerful (NRL = 680 ± 99 W) than SRL (591 ± 72 W, ES = 1.037) and CRL players (521 ± 71 W, ES = 1.867). The differences in speed (NRL = 345 ± 31 W, SRL = 319 ± 29 W, CRL = 303 ± 29 W; ES = 0.884 and 1.409, respectively) and strength-endurance (NRL = 36 ± 7 reps, SRL = 32 reps ± 7, CRL = 24 ± 5 reps; ES = 0.521 and 1.984, respectively) were not as pronounced.Conclusions:Of the tests undertaken, maximal strength best describes players who attain NRL ranking. Maximum power and strength-endurance were also strong descriptors of attainment of NRL level. Upper body speed appears less likely to strongly discriminate between players who attain NRL level and those who do not. These results tended to hold true across the different team positional groupings.


2020 ◽  
Vol 10 (18) ◽  
pp. 6562
Author(s):  
Sergio Sebastia-Amat ◽  
Alfonso Penichet-Tomas ◽  
Jose M. Jimenez-Olmedo ◽  
Basilio Pueo

The purpose of this study was to analyze the contribution of anthropometric and strength determinants of 2000 m ergometer performance in traditional rowing. Nineteen rowers competing at national level participated in this study. Anthropometric characteristics, vertical jumps and bench pull tests were assessed to determine conditional factors, whereas the 2000 m test was used to set rowing performance. Pearson correlation coefficient, linear stepwise and allometric regression analyses were used to predict rowing performance (R2 > 50%). Height, body mass and body muscle correlated with rowing performance in male and female rowers. Similarly, power output for squat jump and countermovement jump power correlated with performance. Finally, mean propulsive velocity, mean power and maximum power in bench pull also correlated with the test. Stepwise multiple regression analysis identified body mass (R2 = 0.69, p < 0.001) and mean propulsive velocity in bench pull (R2 = 0.76, p < 0.001) for male rowers and body muscle (R2 = 0.89, p = 0.002) and maximum power in bench pull (R2 = 0.62, p = 0.036) for female rowers as the best predictors of rowing performance. These results determine the relevance of anthropometric characteristics and, in contrast to Olympic rowing, support the greatest importance of upper body power in traditional rowing training.


1995 ◽  
Vol 27 (Supplement) ◽  
pp. S211 ◽  
Author(s):  
S. C. Hui ◽  
M. T. Mahar ◽  
A. S. Jackson

2015 ◽  
Vol 47 ◽  
pp. 615
Author(s):  
David D. Church ◽  
Gerald T. Mangine ◽  
Adam M. Gonzalez ◽  
Jeremy R. Townsend ◽  
Adam J. Wells ◽  
...  

2016 ◽  
Vol 11 (4) ◽  
pp. 515-521 ◽  
Author(s):  
Chelsea L. Oxendale ◽  
Craig Twist ◽  
Matthew Daniels ◽  
Jamie Highton

Purpose:While exercise-induced muscle damage (EIMD) after rugby league match play has been well documented, the specific match actions that contribute to EIMD are unclear. Accordingly, the purpose of this study was to investigate the positional demands of elite rugby league matches and examine their relationship with subsequent EIMD.Methods:Twenty-eight performances (from 17 participants) were captured using 10-Hz global positioning systems over 4 competitive matches. Upper- and lower-body neuromuscular fatigue, creatine kinase (CK), and perceived muscle soreness were assessed 24 h before and at 12, 36, and 60 h after matches.Results:High-intensity running was moderately higher in backs (6.6 ± 2.6 m/min) than in forwards (5.1 ± 1.6 m/min), whereas total collisions were moderately lower (31.1 ± 13.1 vs 54.1 ± 37.0). Duration (r = .90, CI: .77–.96) and total (r = .86, CI: .70–.95) and high-intensity distance covered (r = .76, CI: .51–.91) were associated (P < .05) with increased CK concentration postmatch. Total collisions and repeated high-intensity efforts were associated (P < .05) with large decrements in upper-body neuromuscular performance (r = –.48, CI: –.74 to .02; r = –.49, CI: –.77 to .05, respectively), muscle soreness (r = –.68, CI: –.87 to –.10, r = –.66, CI: –.89 to .21, respectively), and CK concentration (r = .67, CI: .42–.85; r = .73, CI: .51–.87, respectively). All EIMD markers returned to baseline within 60 h.Conclusion:Match duration, high-intensity running, and collisions were associated with variations in EIMD markers, suggesting that recovery is dependent on individual match demands.


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