Relationships between physical qualities and key performance indicators during match-play in senior international rugby union players

Abstract

The use of physical tests to profile physical capabilities, and provide training direction to athletes is common practice. Likewise, in professional team sports, notational analysis codes the key contributions of each player during competition. Limited studies have however investigated relationships between physical capabilities and key performance indicators (KPIs) of rugby union match-play. Elite professional players, categorised as forwards (n = 15) or backs (n = 14), from an international rugby union squad (n = 29) undertook assessments of isometric mid-thigh pull (IMTP), bilateral and unilateral countermovement jumps (CMJ) and drop jumps (DJ; from 40 and 20 cm, respectively), and assessment of acceleration (10 m), a 5 m weighted sled drive, and a Yo-Yo intermittent recovery test level 1 (Yo-Yo IRTL1). Game statistics of the same players from 92 matches (~23 matches per player) during the 2014–15 season were analysed for effort and performance-based metrics. For forwards, Yo-Yo IRTL1 correlated significantly with; number of tackles made (r = 0.717), first three players at a ruck in both attack (r = 0.568) and defence (r = 0.581), number of effective rucks (r = 0.630), total possessions (r = 0.522), passes made (r = 0.651), percentage of carries over the gainline (r = 0.610), effective ruck success (r = 0.600), tackle success (r = 0.540), and the number of turnovers made (r = 0.518). Drop jump performance in forwards was associated with; the number of clean breaks (r = 0.558), dominant collisions (r = 0.589), and offloads (r = 0.594). For backs, the sled-drive test correlated with; number of carries (r = -0.751), first three players at an attacking ruck (r = -0.613), effective attacking rucks (r = -0.584), number of dominant collisions (r = -0.792) and offloads (r = -0.814). Likewise, for backs, IMTP peak force was related to; the number of possessions (r = 0.793), passes made (r = 0.792), effective attacking ruck percentage (r = 0.628), and the number of offloads (r = 0.621) whilst relative peak force correlated with; the percentage of carries over the gainline (r = 0.533), percent tackle success (r = 0.603) and effective attacking ruck percentage (r = 0.584). Regression analyses highlighted that only a small number of variables (i.e., carries, tackles, attacking and defensive first three at ruck) returned practically achievable changes (<20%) in physical qualities. In spite of this, and while leaving scope identification of further physical and/or performance predictors, greater strength, power and intermittent running performance were positively related to match-derived KPIs during competition. This may provide a basis for better integrating the strategies used by physical and technical performance-focused coaching staff to improve key performance indicators, and thus match performance, of rugby union players.

Change of Direction Deficit in National Team Rugby Union Players: Is There an Influence of Playing Position?

“…As expected, forwards generated greater sprint momentum than backs, in accordance with previous literature [3,24,25]. In collision sports such as rugby, sprint momentum is of considerable importance [26].…”

“…Notably, no differences were found in COD deficit when comparing backs and forwards; by contrast, when using the median split analysis, faster players presented an inferior ability to change direction (i.e., greater COD deficits), independently of the angles of direction changes. This interesting finding indicates that separating rugby players by positional group might not be sensitive enough to discriminate between players of different COD skills, contrary to what has been reported for other speed–power variables (e.g., CMJ, SJ, linear sprint, absolute and relative strength) [2,3,23,25]. Therefore, rugby practitioners are strongly encouraged to assess COD ability and maneuverability using the COD deficit [10,11,12] and, subsequently, apply a median split analysis relative to linear speed to better identify player-specific training needs.…”

Testing methods and physical qualities of male age grade rugby union players: A systematic review

“…To account for the effect of body mass, allometric or ratio scaling can be used to normalise strength and power where a larger muscle mass is beneficial [81,82]. In contrast, greater body mass is detrimental for speed performance but contributes to a higher sprint momentum which is shown to relate to collision success in International RU [6]. Although under reported in age grade RU relative measures of 30-15IFT [73] and speed performance [71] have shown to differentiate between age grade and senior RU players where absolute measures did not.…”

“…To support the development of young RU players towards the senior game, many national governing bodies have established age grade development pathways culminating with the Under 20 (U20) World Championship. Developing technical, tactical and physical qualities throughout the pathway is key to enhancing RU performance [5][6][7][8]. RU match play is complex, with collisions, high speed running, and technical elements being interspersed with periods of recovery [9,10].…”

Rugby game performances and weekly workload: Using of data mining process to enter in the complexity

“…One of the main reasons certainly resides in the difficulty to identify and evaluate the key performance indicators (individual and collective) in team-sports. Nevertheless, for some time now, various studies succeed to reveal some tactical, technical and physical key performance indicators during RU games at different age categories and level of play [10,11,12]. Furthermore, elements of research outline some individual technical skills as being directly correlated to playing performance.…”