Journal of Strength and Conditioning Research Publish Ahead of Print DOI: 10.1519/JSC.0000000000001348
PHYSICAL PERFORMANCE OF BRAZILIAN RUGBY PLAYERS FROM DIFFERENT AGE-CATEGORIES AND COMPETITIVE LEVELS
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Kitamura1, Cesar C. Cal Abad1, Lucas A. Pereira¹, Irineu Loturco1
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Ronaldo Kobal1, Fábio Y. Nakamura1,2, José E. Moraes3, Maurício Coelho4, Katia
1 - NAR - Nucleus of High Performance in Sport, São Paulo, SP, Brazil
2 - Department of Physical Education, State University of Londrina, PR, Brazil
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3 - CBRU – Brazilian Confederation of Rugby 4 – São José Rugby Club, SP, Brazil
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Running head: Physical performance in rugby players
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Corresponding author: Irineu Loturco
Nucleus of High Performance in Sport – São Paulo Av. Padre José Maria, 555 – 04753 – 060 - São Paulo – SP – Brazil Phone: +55 11 3758-0918 Fax: +55 11 3758-0918 e-mail:
[email protected]
Copyright ª 2016 National Strength and Conditioning Association
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ABSTRACT The aim of this study was to compare the anthropometric characteristics and physical
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capacities (vertical jumping, speed, agility, and endurance abilities) among different age -
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categories of Brazilian rugby players from the same high-level club and to compare their
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respective data with those obtained by the national team players. Eighty-eight male Brazilian
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rugby players from four different age categories were divided into four different groups (i.e., U-
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15, U-17, U-19, and professional senior team [PRO]) and a group composed of players from the
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Brazilian national team (NAT). Anthropometric measures (i.e., height and body mass), squat
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jump and countermovement jump tests (SJ and CMJ), two agility tests (COD and Pro-agility),
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40m sprinting, and the Yo-Yo endurance test level 1 were compared among the groups using
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analysis of covariance (multi-variables MANCOVA) with the body mass as a covariate. The
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NAT group demonstrated significantly greater performances in all variables compared to the U-
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15, U-17, U-19, and PRO groups (P < 0.05). Moreover, the PRO group demonstrated better
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performances in vertical jumping assessments (i.e., SJ and CMJ) and agility tests (i.e., COD and
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Pro-agility) than the younger categories (P < 0.05). Finally, except for the U-15, no significant
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differences were found between the young age-categories in sprint and endurance capacities.
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These findings show that, throughout the maturation process, rugby players improve their muscle
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power and agility abilities, without presenting significant increases in endurance and sprinting capacities. Importantly, this does not hold true for players from the NAT group, who presented
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superior performance in all assessed physical variables (in comparison to the younger and PRO
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categories).
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Keywords: muscle power; young athletes; plyometrics; team sports; speed performance
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INTRODUCTION Rugby is an intermittent sport characterized by bouts of high-intensity activities (i.e.,
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sprints, acceleration/deceleration and changes of direction [COD]) interspersed with bouts of
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lower-intensity activities (e.g. standing, walking and jogging), with a high frequency of physical
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collisions (i.e., tackles, scrums, rucks and mauls) (7, 15). Due to the complex demands, a better
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characterization of the physical capacities related to rugby performance (e.g., muscle power,
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speed, agility and endurance), which are expected to change across age-categories in prospective
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players, is needed. In addition, determining which capacities differentiate between elite and less
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qualified players may be relevant to enable implementation of effective training programs at the
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top-level of athletes’ preparation.
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In this regard, it is well established that the physical performance (i.e., assessed by means
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of vertical jumps, maximum strength assessments and endurance tests) of team sports players
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improves throughout their participation in development programs, due to the accumulation of
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training experience and the biological maturation process (6, 11, 25). However, these data in
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rugby are limited to some specific age-categories, such as very young “novices” (13-16 years) (8,
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9) or young professionals (16-21 years), (6, 10, 25). This fact makes it difficult to ascertain what
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typically occurs during the transition phases between the younger and professional rugby categories. For instance, Darrall-Jones et al. (6) compared three distinct age-categories of rugby
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players from the English academy (i.e., under-16, under-18, and under-21), reporting that the
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older athletes were taller and heavier and presented superior performances in vertical jumping
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and maximum strength tests. Curiously, for sprinting and endurance capacities, no significant
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differences were found between the three different age-categories. Moreover, Baker and Newton
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(1) reported no differences in sprinting and agility abilities among rugby players from distinct
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competitive levels (i.e., Australian elite first-division national rugby league versus second-
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division state league). Although these authors performed this investigation with rugby league
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players (instead of rugby union athletes), these data highlight the controversial questions
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regarding the possible evolution of the physical performance of top-level rugby players
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throughout the distinct phases of the maturation process. Hence, there is a lack of information
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related to which physical capacities are capable of differentiating athletes of different ages and
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also those selected to participate in the national team. From an applied perspective, a better
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understanding of the possible differences between different age-categories may allow coaches
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and sports scientists to adopt more adequate strategies for training and selecting young and elite
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rugby athletes.
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Therefore, this study aimed to compare the anthropometric characteristics (i.e., height
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and body mass) and physical capacities (vertical jumping, speed, agility, and endurance abilities)
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among different age-categories of Brazilian rugby players of the same high-level club (under-15,
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under-17, under-19, and professional) and to compare their respective data with those obtained
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for national team players. We hypothesized that: 1) the older and more experienced athletes
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would perform better than their younger counterparts, and 2) the players from the national team
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would present superior physical performances to all the other players.
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METHODS
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Experimental Approach to the Problem
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This cross-sectional study was designed to compare anthropometric characteristics
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(height and body mass) and physical performance (vertical jump height, speed, agility and
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endurance) of rugby players from four different age-categories from the same high-level club,
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and the national team (so-called National). Prior to the actual tests, all participants visited the
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laboratory on one occasion for familiarization with the procedures of this study. Besides this, the
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athletes were all previously familiarized with the tests due to their normal training and
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assessment routines. The experimental sessions took place over two days, separated by a
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minimum of 48 hours, in the following order: day 1 – anthropometric measures, squat jump and
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countermovement jump tests, agility, and sprint assessments; day 2 – Yo-Yo endurance test,
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level 1. Prior to all assessments, a standardized warm-up protocol was performed, including
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general (i.e., running at a moderate pace for 5 mins followed by 3 mins of lower limb light active
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stretching) and specific exercises. Three minutes after the warm-up, the players were required to
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perform the tests. All assessments were completed in the same month, during the in-season
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training period (after the pre-season), attesting that all athletes were close to their peak
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performance.
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Subjects
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Eighty-eight male Brazilian rugby players from four different age categories, divided into
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four different groups from the same rugby club (i.e., U-15, U-17, U-19, and PRO), and a group
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composed of players from the Brazilian national team (NAT) (including five players from the investigated club) participated in this study (Table 1). The following players were enrolled in the
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Brazilian First Division Championship of their respective age-categories. The five players from
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the club called for the national team were considered part of the NAT group. Currently, the
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Brazilian national team occupies the 39th position in the International Rugby Board (IRB)
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ranking, of 102 national teams. The players involved in this study were part of one of the most
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traditional rugby clubs in Brazil. Of note, the PRO players from this club have won the Brazilian
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national championship (the most important rugby union competition in Brazil for senior rugby
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players) 9 times (including the national championship disputed in 2015). All assessments took
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place at the beginning of the pre-season. The study procedures were approved by a local Ethics
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Committee, and the participants and their legal guardians (in the case of