Semi-professional Rugby League Players Research Articles

ANTHROPOMETRIC AND PHYSICAL QUALITIES OF SEMI-PROFESSIONAL RUGBY LEAGUE PLAYERS

AIM The aim of the current study was to investigate the physiological and anthropometric characteristics of semi-professional rugby league players across a typical season, including pre- and post-season data. METHODS Thirty-five semi-professional rugby league players, mean age 25.38 ± 2.35 years were measured for height, body mass, sum of skinfolds, and speed (20m sprint). Global positioning system (GPS) data, sampling at 10 Hz, were collected, two pre-season and eighteen Queensland Cup rugby league matches in the 2023 season for 10 players (backs and forwards). Data was categorized into total distance (km), sprint distance (m), power plays, energy expenditure (kcal), player load, and top speed (m/s). RESULTS Compared with forwards the backs had significantly lower body mass (99.4kg vs 90.8kg), and significantly greater speed during 20m sprint (3.00 vs 3.1sec). Sum of skinfolds, no differences between backs and forwards across the three time points, 104.2 vs 106.2mm, 103.9 vs 110.9mm and 93.8 vs 108.1mm. Reviewing the GPS data across the trial and cup games revealed a number of significant differences between backs and forwards, backs greater overall distance (6.63km vs 5.26km), sprint distance (467.53 vs 264.63m), power plays (37 vs 25), energy expenditure (1002.42 vs 778.90 kcal), player load (311.50 vs 275.16), top speed (8.02 vs 7.02m/s). CONCLUSION Retrospective analysis of our data has allowed us to understand the activity demands between match types and differences in activity demands between seasonal phases of training in semi-professional male rugby league players and will permit further specificity of training and improve performance. Determining the fitness and physiological profiles and how they relate to training and match demands will allow the coaching staff to develop more targeted training strategies in order to optimally develop the fitness characteristics that predominantly underpin match demands.

Anthropometric and physical qualities of semi-professional rugby league players

Anthropometric and physical qualities of semi-professional rugby league players

The pre- and post-pitch-entry physical and technical responses of rugby league interchange players according to starting status

This study quantified the activities of interchange players during the 15 min before and 20 min after initial pitch-entry (INTentry) or re-entry (INTre−entry) for substitutes and starters, respectively, and identified relationships between pre- and post-pitch-entry responses. Fourteen semi-professional rugby league players wore Microelectromechanical Systems and were filmed throughout 10 matches in which they were interchanged (68 observations). Twelve physical and technical variables were analyzed for the pre-match warm-up, five, 10, and 15 min before INTentry or INTre−entry (physical variables only), and five min epochs following match-introduction. Linear mixed models indicated that during the 0–5 min following INTentry, physical and technical responses were typically greater (∼7.1% to 66.3%) than subsequent epochs while total (∼6.2%) and high-speed (37.1%) distance also exceeded the 0–5 min after INTre−entry (p < 0.05). Edge forwards reached higher peak speeds (11.4% to 11.7%) than hookers and middle forwards, but hookers completed more passes (87.4% to 90.5%). Pre-pitch-entry movements were positively associated with post-pitch-entry tackles (r = 0.43 to 0.49) and high-speed distance (r = 0.46), but negatively associated with total distance (r = −0.32 to −0.68). Within tolerable limits, increasing the activity performed during the ∼15 min before pitch-entry could benefit high-speed match-play performance indicators. Transient changes in post-pitch-entry physical and technical responses could reflect self-pacing strategies, contextual factors, or perceived preparedness. The apparent absence of progressive performance-limiting fatigue, characterized by a plateau in responses after the initial five min following INTentry or INTre−entry, may suggest a role for interchange players to provide a more sustained impact and thus achieve interchange objectives.

Validity of Real-Time Ultra-wideband Global Navigation Satellite System Data Generated by a Wearable Microtechnology Unit.

Johnston, RD, Hewitt, A, and Duthie, G. Validity of real-time ultra-wideband global navigation satellite system data generated by a wearable microtechnology unit. J Strength Cond Res 34(7): 2071-2075, 2020-This study aimed to determine the validity of real-time ultra-wideband data generated by a wearable microtechnology unit during rugby league training sessions using a repeated-measures crossover study. Twenty-four semiprofessional rugby league players wore a commercially available microtechnology device (StatSports Apex, Newry, Northern Ireland) during 10 training sessions. Total distance; moderate-speed running (3.6-4.9 m·s); high-speed running (5.0-6.9 m·s); very high-speed running (≥7 m·s); maximum velocity (m·s); the number of high-intensity accelerations (≥2.78 m·s) and decelerations (≥-2.78 m·s); dynamic stress load (AU); and high metabolic load distance (m) were recorded in real time through an Apex beacon over a secured wireless network before being exported to a csv file at the end of the session. The data were then downloaded to a computer after event. To determine the validity of the real-time data, they were compared with the postevent downloaded data using coefficient of variation and Pearson's correlation coefficient. There was almost perfect agreement between real-time and postevent downloaded data for all variables reported. The overall bias effect size scores were all trivial, ranging from 0.00 for total distance and high-speed running up to -0.12 for maximal velocity; Pearson's correlations were either perfect or nearly perfect (r = 0.98-1.00). Irrespective of the movement speed, the data collected by these devices in real time show excellent levels of agreement with postevent downloaded data.

Influence of Physical Characteristics and Match Outcome on Technical Errors During Rugby League Match Play.

To explore the relationship between technical errors during rugby league games, match success, and physical characteristics. A total of 27 semiprofessional rugby league players participated in this study (24.8 [2.5]y, 183.5 [5.3]cm, 97.1 [11.6]kg). Aerobic fitness, strength, and power were assessed prior to the start of the competitive season before technical performance was tracked during 22 competitive fixtures. Attacking errors were determined as any error that occurred in possession of the ballthat resulted in a handover to the opposition. Defensive errors included line breaks, penalties, and missed or ineffective tackles. Match outcome, the zone on the field in which each error occurred, and the number of errors in an error chain (≤60s between errors) were assessed. During a loss, there were more defensive errors in the 0- to 40-m zone than when a match was won (effect size = 0.99 [0.04-1.94]). Error chains were a predictor of conceding a try (P = .0001, r2 = .22), with the odds ratio increasing to 2.33 when there were 7 errors per chain. High lower-body strength was associated with fewer defensive errors for backs (Bayes factor = 3.67) and forwards (Bayes factor = 19.31); relative bench press was also important for backs (Bayes factor = 3.21). Fewer defensive errors occur in the 0- to 40-m zone during winning matches; lower-body strength is strongly associated with fewer defensive errors in rugby league players.

Posture of rugby league players and its relationship to non-contact lower limb injury: A prospective cohort study

ObjectiveThis study aimed to identify posture deviations in rugby league players, and to observe relationships between posture and the incidence of non-contact lower limb injury. DesignProspective cohort. SettingLaboratory and on-field. ParticipantsJunior representative, semi-professional and professional rugby league players (n = 207). Main outcome measuresStatic posture scores from photographs (Watson and MacDonncha tool) in pre-season; non-contact lower limb injury surveillance and exposure data. MethodsChi-square and logistic regression analyses were used to observe relationships between postural components and the incidence of non-contact lower limb injury. Results8.7% of players sustained a quadriceps injury; 7.2% sustained a calf injury. Semi-professional and professional players had the highest injury rates. The most common posture deviations were having a forward shoulder position (46.9%), a forward head position (33.3%), a varus knee interspace (32.9%) or a lumbar lordosis (30.9%). A moderate C-scoliosis deviation was associated with a decrease in injury risk (OR 1.57 95% CI 1.00-2.46 p = 0.052). Included in the model was player weight, which was associated with an increased risk of injury (OR 1.04 95% CI 1.01-1.07 p = 0.010). ConclusionsAlthough postural deviations are common in rugby league players, given the lack of association with injury, they may not warrant intervention.

Verifying Head Impacts Recorded by a Wearable Sensor using Video Footage in Rugby League: a Preliminary Study

BackgroundRugby league is a full-contact collision sport with an inherent risk of concussion. Wearable instrumented technology was used to observe and characterize the level of exposure to head impacts during game play.PurposeTo verify the impacts recorded by the x-patch™ with video analysis.Study designObservational case series.MethodsThe x-patch™ was used on eight men’s semi-professional rugby league players during the 2016 Newcastle Rugby League competition (five forwards and three backs). Game day footage was recorded by a trained videographer using a single camera located at the highest midfield location to verify the impact recorded by the x-patch™. Videographic and accelerometer data were time synchronized.ResultsThe x-patch™ sensors recorded a total of 779 impacts ≥ 20 g during the games, of which 732 (94.0%) were verified on video. In addition, 817 impacts were identified on video that did not record an impact on the sensors. The number of video-verified impacts ≥ 20 g, per playing hour, was 7.8 for forwards and 4.8 for backs (range = 3.9–19.0). Impacts resulting in a diagnosed concussion had much greater peak linear acceleration (M = 76.1 g, SD = 17.0) than impacts that did not result in a concussion (M = 34.2g, SD = 18.0; Cohen’s d = 2.4).ConclusionsThe vast majority (94%) of impacts ≥ 20 g captured by the x-patch™ sensor were video verified in semi-professional rugby league games. The use of a secondary source of information to verify impact events recorded by wearable sensors is beneficial in clarifying game events and exposure levels.

Verifying head impacts recorded by a wearable sensor using video footage in Rugby league: A preliminary study

Rugby league is a full-contact collision sport with an inherent risk of concussion. Wearable instrumented technology was used to observe and characterize the level of exposure to head impacts during game play. To verify the impacts recorded by the x-patch™ with video analysis. Observational case series. The x-patch™ was used on eight men’s semi-professional rugby league players during the 2016 Newcastle Rugby League competition (five forwards and three backs). Game day footage was recorded by a trained videographer using a single camera located at the highest midfield location to verify the impact recorded by the x-patch™. Videographic and accelerometer data were time synchronized. The x-patch™ sensors recorded a total of 779 impacts ≥ 20 g during the games, of which 732 (94.0%) were verified on video. In addition, 817 impacts were identified on video that did not record an impact on the sensors. The number of video-verified impacts ≥ 20 g, per playing hour, was 7.8 for forwards and 4.8 for backs (range = 3.9–19.0). Impacts resulting in a diagnosed concussion had much greater peak linear acceleration (M = 76.1 g, SD = 17.0) than impacts that did not result in a concussion (M = 34.2g, SD = 18.0; Cohen’s d = 2.4). The vast majority (94%) of impacts ≥ 20 g captured by the x-patch™ sensor were video verified in semi-professional rugby league games. The use of a secondary source of information to verify impact events recorded by wearable sensors is beneficial in clarifying game events and exposure levels.

Changes in Rugby League Tackling Ability During a Competitive Season: The Relationship With Strength and Power Qualities.

Speranza, MJA, Gabbett, TJ, Greene, DA, Johnston, RD, and Sheppard, JM. Changes in rugby league tackling ability during a competitive season: the relationship with strength and power qualities. J Strength Cond Res 31(12): 3311-3318, 2017-This study examined the relationship between changes in tackling ability, and muscular strength and power during a semiprofessional rugby league competitive season. Twelve semiprofessional rugby league players (mean ± SD age, 23.3 ± 2.0 years) underwent tests of upper- and lower-body strength and power during the preseason period. Tackling ability was tested using video analysis of a standardized one-on-one tackling drill. Players repeated these tests after round 15 of a 25-match competitive season. Changes in 1 repetition maximum (1RM) squat (rs = 0.70; p < 0.02) and squat relative to body mass (rs = 0.73; p < 0.01) were significantly related to changes in tackling ability. Players with the greatest improvements in tackling ability (i.e., "responders") retained 1RM squat (effect size, ES = 0.85, p = 0.09) and squat relative to body mass (ES = 0.82, p = 0.15) to a greater extent than the "nonresponders." The results of this study suggest that players who retained lower-body strength were able to improve tackling ability during the competitive season, whereas reductions in lower-body strength were associated with decrements in tackling ability. This study highlights the importance of the development and maintenance of lower-body muscular strength for effective tackling performance throughout the rugby league season.

Relationship Between 2 Standardized Tackling Proficiency Tests and Rugby League Match-Play Tackle Performance.

This study investigated the relationship between 2 different assessments of tackling ability, physical qualities, and match-play performance in semiprofessional rugby league players. A total of 18 semiprofessional rugby league players (mean [SD]: age = 23.1 [2.0]y and body mass = 98.8 [11.8]kg) underwent tests of upper- and lower-body strength and power. Tackling ability was assessed using video analysis of under- and over-the-ball tackle drills. A total of 2360 tackles were analyzed from match play. Over-the-ball tackle ability was positively related to the proportion of dominant tackles (Spearman rank-order correlation coefficients [rs] = .52; 95% confidence interval [CI] .07-.79, P = .03) and average play-the-ball speeds (rs = .50; 95% CI .04-.78, P = .03) and negatively related to tackles that conceded offloads (rs = -.55; 95% CI -.78 to .04, P = .04). Under-the-ball tackle ability was significantly related to the proportion of dominant tackles (rs = .57; 95% CI .14-.82, P = .01) and missed tackles (rs = -.48; 95% CI -.77 to .02, P = .05). Good over-the-ball tacklers performed proportionally more dominant tackles, allowed significantly fewer offloads, and had longer average play-the-ball speeds. Good under-the-ball tacklers missed proportionately fewer tackles. This study suggests that both the under-the-ball and over-the-ball standardized tackle assessments are associated with varying indicators of match-play tackle performance and justifies the practical utility of these tests to assess and develop both types of tackles.

An Alternative Test of Tackling Ability in Rugby League Players.

This study investigated the relationship between 2 tests of tackling ability, muscle strength, and power in semiprofessional rugby league players. Thirty-one players, 19 first-grade and 12 second-grade, underwent tests of muscle strength (1-repetition-maximum bench press, chin-up, and squat) and power (plyometric push-up and countermovement jump). Tackling ability was assessed via video analysis of under-and over-the-ball tackle drills. The first-grade players had significantly greater scores in both the under-the-ball (P = .03, effect size [ES] = 0.84, 95% CI 0.07-1.50) and over-the-ball tackling-ability tests (P < .001, ES =1.86, 95% CI 0.83-2.52) than the second-grade players. A large, significant relationship was found between under- and over-the-ball tackling ability (r = .55, 95% CI .24-.76, P = .001). Lower-body strength (r = .37, 95% CI .02-.64, P = .04) was moderately associated with under-the-ball tackling ability, whereas over-the-ball tackling ability was moderately associated with plyometric push-up performance (r = .39, 95% CI .04-.65, P = .03). This study found that over-the-ball tackling ability was significantly associated with under-the-ball tackling in semiprofessional rugby league players. Furthermore, it was found that, compared with the second-grade players, the first-grade players had superior tackle ability in both tackle drills. In this study it was observed that plyometric push-up peak power was significantly related to over-the-ball tackling ability and absolute lower-body strength was associated with under-the-ball tackling ability. These findings provide skill coaches and strength and conditioning staff a greater understanding of elements that contribute to effective tackling ability.

THE DEVELOPMENT AND VALIDATION OF A RUGBY LEAGUE MATCH SIMULATION – INTERCHANGE PROTOCOL WITH COLLISION ELEMENTS

Rugby league is a collision sport that is intermittent in nature. Players require highly developed maximal aerobic power, muscular strength and power and speed and agility, to perform through an...

Influence of Fatigue on Tackling Ability in Rugby League Players: Role of Muscular Strength, Endurance, and Aerobic Qualities.

This study investigated the influence of repeated high-intensity effort exercise on tackling ability in rugby league players, and determined the relationship between physical qualities and tackling ability under fatigued conditions in these athletes. Eleven semi-professional rugby league players underwent measurements of speed (10 m and 40 m sprint), upper-body strength (4 repetition maximum [RM] bench press and weighted chin-up), upper-body muscular endurance (body mass maximum repetition chin-up, body mass maximum repetition dips), lower-body strength (4RM squat), and estimated maximal aerobic power (multi-stage fitness test). Tackling ability was assessed using a standardized one-on-one tackling test, before, during, and following four bouts of repeated high-intensity effort (RHIE) exercise. The relationship between physical qualities and fatigue-induced decrements in tackling ability were determined using Pearson product moment correlation coefficients. Each cycle of the RHIE protocol induced progressive reductions in tackling ability. A moderate reduction (Effect Size = ~-1.17 ± 0.60, -34.1 ± 24.3%) in tackling ability occurred after the fourth cycle of the RHIE protocol. Players with greater relative lower-body strength (i.e. 4RM squat/kg) had the best tackling ability under fatigued conditions (r = 0.72, p = 0.013). There were no significant relationships between tackling ability under fatigued conditions and any other physical quality. These findings suggest that lower-body strength protects against fatigue-induced decrements in tackling ability. The development of lower-body strength should be a priority to facilitate the development of robust tackling skills that are maintained under fatigue.

The Application of Naturalistic Decision-Making Techniques to Explore Cue Use in Rugby League Playmakers

Within the sport of rugby league, there exists a perceived shortage of talent in playmaking positions. In Australia, an academy dedicated to the development of playmaking skills has recently been established. Although the precise skills targeted by the academy for development are yet to be determined, decision making is presumed to be integral. The current research used the naturalistic decision-making paradigm to inform training initiatives by investigating the decision processes engaged by rugby league playmakers. The research explored whether players of varying ability could be differentiated in relation to a key decision process, cue use. Rugby league playmakers were interviewed using a novel variation of cognitive task analysis, which used both retrospective (i.e., recalled game) and prospective (i.e., unfamiliar rugby league scenario) means. The sample comprised 10 participants: six professional and four semiprofessional rugby league players. From a content analysis, a concept map, cognitive demands tables, and a critical cue inventory were produced. Results indicated that professional players demonstrated greater cue discrimination, assigned different meaning to the cues, and processed cues in a different manner compared with their semiprofessional counterparts. The results offer insights for future training applications in the domain and raise important questions regarding the utility of critical cue inventories in training.

The Effect of Caffeine on Repeat-High-Intensity-Effort Performance in Rugby League Players.

Repeat-high-intensity efforts (RHIEs) have recently been shown to occur at critical periods of rugby league matches. To examine the effect that caffeine has on RHIE performance in rugby league players. Using a double-blind, placebo-controlled, crossover design, 11 semiprofessional rugby league players (age 19.0 ± 0.5 y, body mass 87.4 ± 12.9 kg, height 178.9 ± 2.6 cm) completed 2 experimental trials that involved completing an RHIE test after either caffeine (300 mg caffeine) or placebo (vitamin H) ingestion. Each trial consisted of 3 sets of 20-m sprints interspersed with bouts of tackling. During the RHIE test, 20-m-sprint time, heart rate (HR), rating of perceived exertion (RPE), and blood lactate were measured. Total time to complete the nine 20-m sprints during the caffeine condition was 1.0% faster (28.46 ± 1.4 s) than during the placebo condition (28.77 ± 1.7 s) (ES = 0.18, 90%CI -0.7 to 0.1 s). This resulted in a very likely chance of caffeine being of benefit to RHIE performance (99% likely to be beneficial). These improvements were more pronounced in the early stages of the test, with a 1.3%, 1.0%, and 0.9% improvement in sprint performance during sets 1, 2, and 3 respectively. There was no significant difference in RPE across the 3 sets (P = .47, 0.48, 1.00) or mean HR (P = .36), maximal HR (P = .74), or blood lactate (P = .50) between treatment conditions. Preexercise ingestion of 300 mg caffeine produced practically meaningful improvements in RHIE performance in rugby league players.

Semi-Professional Rugby League Players have Higher Concussion Risk than Professional or Amateur Participants: A Pooled Analysis.

A combined estimate of injuries within a specific sport through pooled analysis provides more precise evidence and meaningful information about the sport, whilst controlling for between-study variation due to individual sub-cohort characteristics. The objective of this analysis was to review all published rugby league studies reporting injuries from match and training participation and report the pooled data estimates for rugby league concussion injury epidemiology. A systematic literature analysis of concussion in rugby league was performed on published studies from January 1990 to October 2015. Data were extracted and pooled from 25 studies that reported the number and incidence of concussions in rugby league match and training activities. Amateur rugby league players had the highest incidence of concussive injuries in match activities (19.1 per 1000 match hours) while semi-professional players had the highest incidence of concussive injuries in training activities (3.1 per 1000 training hours). This pooled analysis showed that, during match participation activities, amateur rugby league participants had a higher reported concussion injury rate than professional and semi-professional participants. Semi-professional participants had nearly a threefold greater concussion injury risk than amateur rugby league participants during match participation. They also had nearly a 600-fold greater concussion injury risk than professional rugby league participants during training participation.

Effect of Strength and Power Training on Tackling Ability in Semiprofessional Rugby League Players.

This study examined the influence of a strength and power program on tackling ability in rugby league players. Twenty-four semiprofessional rugby league players (mean ± SD age, 23.4 ± 3.1 years) underwent tests of upper-body strength (3 repetition maximum [RM] bench press), lower-body strength (3RM squat), upper-body power (plyometric push-up), and lower-body power (countermovement jump [CMJ]). Muscular strength relative to body mass was also calculated. Tackling ability of the players was assessed using video analysis of a standardized one-on-one tackling drill. The players then underwent 8 weeks of strength and power training as part of their preseason training before being retested. Training resulted in significant (p ≤ 0.01) improvements in absolute and relative measures of squat, bench press, CMJ peak power, and plyometric push-up peak power. The strongest correlates of change in tackling ability were changes in 3RM squat (r = 0.60; p < 0.01) and squat relative to body mass (r = 0.54; p < 0.01). The players with the greatest improvements in 3RM squat and squat relative to body mass (i.e., responders) had significantly greater improvements in tackling ability than nonresponding players (p = 0.04; effect size [ES] ≥ 0.85). A small, nonsignificant difference (p = 0.20; ES = 0.56) in tackling ability was found between responders and nonresponders for lower-body power. The findings of this study demonstrate that the enhancement of lower-body muscular strength, and to a lesser extent muscular power, contribute to improvements in tackling ability in semiprofessional rugby league players.

Motion Capture System versus Common Force Platform Methodologies for Vertical Jump Analysis

Background: This study compared vertical jump phase identification using a three-dimensional motion capture system to three common force platform based methodologies. Methods: Thirty-two semi-professional male rugby league players (23.3 ± 4.1 years) volunteered to participate in the study. Participants completed six vertical jumps on a force plate with landmark body markers for the motion capture system analysis. The data from the motion capture system was then analysed against three common methods used in vertical jump analysis. Results: Eccentric phase time, concentric phase time, time to peak force and rate of force development for method one were significantly different (p<0.001) from motion capture system data. Method 2 was significantly different (p<0.05) for eccentric phase time identification compared to motion capture analysis. No significant differences were found among the three groups for maximum concentric force when compared with motion capture system data. Conclusion: While no differences were found in the maximum force values, differences were found in the eccentric and concentric phase times. The accurate identification of the start and ending of the phases is essential to correctly measure the time to peak force and rate of force development during the vertical jump. The rate of force development and time to peak force has been identified as key predictors of sports performance and therefore care must be taken in the methods chosen to measure these important variables.

Repeated High-Intensity Effort Activity in Relation to Tries Scored and Conceded during Rugby League Match-Play.

To examine the nature and frequency of rugby league repeated high-intensity effort (RHIE) activity in relation to tries scored and conceded in successful and unsuccessful teams. One-hundred and eighty-five semi-professional rugby league players (mean ± SD age: 23.7 ± 3.2 yr) from 11 teams participated in this study. Global positioning system (GPS) data was collected during 21 matches. Data were analysed for the total number of RHIE bouts, efforts per bout, duration of efforts and recovery between efforts. Using notational analysis, a RHIE bout frequency distribution, representing 0-60s, 61-120s, 121-180s, 181-240s, and 241-300s prior to scoring and conceding a try was established. Over 50% of RHIE bouts occurred within five minutes of a try. Bottom 4 teams performed a greater proportion of bouts within five minutes of a try than Top 4 teams (61.5% vs. 48.2%, effect size, ES = 0.69 ± 0.28, p=0.0001). Top 4 teams performed a greater number of RHIE bouts per conceded try (3.0 ± 2.1 vs. 1.6 ± 0.7, ES = 0.74 ± 0.51, p<0.05), while Bottom 4 teams performed a greater number of RHIE bouts per try scored (3.6 ± 2.5 vs. 2.1 ± 1.7, ES = 0.70 ± 0.71, p=0.10). The majority of rugby league RHIE bouts occur at critical periods during match-play. Successful rugby league teams perform more RHIE bouts prior to conceding tries, while unsuccessful teams perform more bouts prior to scoring tries. These findings demonstrate that unsuccessful teams are required to work harder to score tries while successful teams work harder to prevent tries.

Muscular Strength and Power Correlates of Tackling Ability in Semiprofessional Rugby League Players.

This study investigated the relationship between muscular strength and power and tackling ability in semiprofessional rugby league players. Thirty-six semiprofessional (mean ± SD age, 23.1 ± 3.6 years) rugby league players, from 3 distinct playing divisions (first grade, second grade, and under 20s), underwent tests of upper-body strength (3 repetition maximum [RM] bench press), lower-body strength (3RM squat), upper-body power (plyometric push-up [PPU]), and lower-body power (countermovement jump). Muscular strength relative to body mass was also calculated. Tackling ability of the players was tested using video analysis of a standardized one-on-one tackling drill. For all players, the strongest correlates of tackling ability were squat (r = 0.67), bench press (r = 0.58), relative squat (r = 0.41), and PPU (r = 0.56). The strongest correlates of tackling ability in first grade players were squat (r = 0.72), bench press (r = 0.72), relative squat (r = 0.86), and PPU (r = 0.70). For second grade players, only relative squat (r = 0.60) and PPU (r = 0.67) were associated with tackling ability. The strongest correlates of tackling ability in under 20s players were squat (r = 0.77), bench press (r = 0.70), and PPU (r = 0.65). The findings of this study demonstrate that muscular strength and upper-body power contribute to tackling ability in semiprofessional rugby league players. Therefore, as long as the technical aspects of tackling technique are adequately coached and practiced, then enhancements in muscular strength and power may serve as foundational components to underpin improvement in tackling ability.